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OCS Study

MMS 96-0045

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I TAXONOMIC ATLAS OF THE BENTHIC FAUNA OF

THE SANTA MARIA BASIN AND

| WESTERN SANTA BARBARA CHANNEL

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i INAL REPORT Volume8 of 14

I

The Mollusca Part 1mAplacophora, Polyplacophora,Scaphopoda, Bivalvia,

I and Cephalopoda

Edited by:

Paul H. Scott

James A. Blake

Submitted by:

I Science Applications International Corporation

10260 Campus Point Drive

San Diego, Califomia 92121

I For:

UMinerals .S. DepaManagement rtment of theSeInterio rvicer

Pacific OCS Region

770 Paseo Camarillo

I Camarillo, California 93010

Under Contract No. 14-35-0001-30484

I

Minerals Management Service

I Pacific OCS Region July 1996

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DISCLAIMER I

ThSeirsvice, repoU.S. rt hasDepa beenrtment revieweofdthebythInterior e Pacifiand c Outapproved er Continent foralpublication. Shelf Region, TheMineopinions, rals Mange findings, ment I

conclusions or recommendations expressed in this report are those of the authors, and do not

nnot ecessarily consitiutereflendorsement ect the view oforthe Minerals Management Service. Mention of trade names does I

recommendation for use. This report has not been edited for

conformity with Minerals Management Service editorial standards.

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TAXONOMIC DISCLAI MER

This report is not deemed nor intended to be a valid publication for the naming of new taxa as I

stipulated in the Intemational Code of Zoological Nomenclature, Article 8b.

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PROJECTORGANIZATION

]

I PROGRAM MANAGER

Science Applicati DR. ANDREW ons Internati L. LISSNER onal Corporation

10260 Campus Point Drive

I San Diego, California 92121

I DEPUTY PROGRAM MANAGER

I DR. JAMESA. BLAKE

ENSR Consulting and Engineering

I 89 Water Street

Woods Hole, Massachusetts 02543

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I PROJECT TECHNICAL OFFICER

MR.FRANKJ. MANAGO

I U.S. Department of the Interior

Minerals Management Service, Pacific OCS Region

I 770 Paseo Camadllo

Camaxillo, California 93010

I

Co_UrlNG AUrHORS

I DR. EUGENEV. COAN

DR. DOUnLASJ. EERNISSE

I DR. F. G. HOCrmERC DR. AM_IE H. SCHELTEMA

MR.PAULH. Scorn"

I DR. RONALDL. SHIMEK

I

°°.

I 111
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ACCESS NUMBER: 30484.8

TECHNICAL SUMMARY i

STUDY TITLE: Taxonomic Atlas of the Santa Maria Basin and Western Santa Barbara Channet.

REPORT TITLE: Taxonomic Atlas of the Santa Maria Basin and Westem Santa Barbara Channel. Volume i

8. The Molluscs Part 1 m Aplacophora, Polyplacophora, Scaphopoda, Bivalvia, and Cephalopoda.

i

CONTRACT NUMBER: MMS Contract No. 14-35-0001-30484. H

SPONSORING OCS REGION: Pacific. i

APPLICABLE PLANNING AREA: Southern California.

FISCAL YEARS OF PROJECT FUNDING: 1990; 1991;1992; 1993; 1994; 1995; 1996. ii

COMPLETION DATE OF REPORT: April 1996.

COSTS: FY 1989, $229,013; FY 1990, $150,000; FY 1991 $150,000; FY 1993 $150,000; FY 1995 $45,371. H

CUMULATIVE PROJECT COST: $724,384. i

PROJECT MANAGER: Andrew L. Lissner.

AFFILIATION: Science Applications International Corporation. i

i

ADDRESS: 10260 Campus Point Drive, San Diego, California 92121.

i

PRINCIPAL INVESTIGATORS" James A. Blake, Andrew L. Lissner. g

KEY WORDS: Marine invertebrates, Mollusca, Aptacophora, Polyplacophora, Scaphopoda, Bivalvia, i

Cephalopoda, California, Santa Maria Basin, Santa Barbara Channel, continental shelf, i

BACKGROUND: The Taxonomic Atlas of the Santa Maria Basin and western Santa Barbara Channel is an

extension of the benthic reconnaissance (Phase I) and monitoring programs (Phase II) that were conducted i

by the MMS since 1983. The organisms that were collected as part of those programs provide the material

on which the Atlas is developed. In order to fully document the fauna collected by those programs, a series

of 14 volumes will be prepared that provide keys, descriptions, and illustrations of the benthic fauna of the i

hard and soft substrate environments. A team of 40 experts on the fauna has been assembled to carry out =

this work and their contributions are distributed among the 14 volumes.

OBJECTIVES: The objectives of Volume 8 are to introduce the Phylym Mollusca. This volume treats the i

non-gastropod classes. The following 5 classes are treated in this volume: Aplacophora, Polyplacophora,

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Scaphopoda, Bivalvia, and Cephalopoda.

DESCRIPTION: Volume 8 treats the non-gastropod classes and includes the Aplacophora, Polyplacophora, H

Scaphopoda, Bivalvia, and Cephalopoda. The 5 chapters are organized into sections that include the

morphology, taxonomic history, biology, keys of species, and descriptions of genera and species. Each •

species is fully illustrated with relevant characteristics Labeled and identified. =

SIGNIFICANT CONCLUSIONS: The keys, detailed descriptions, and illustrations to the 96 species treated

in this volume represents a major contribution to molluscan systematics for the eastern Pacific Ocean. Many i

poorly know species are newly defined with new illustrations or photographs. Five new aplacophoran species

i

are described, along with diagnoses for one new genus and four new species of bivalves.

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ACCESS NUMBER: 30484.8

I STUDY RESULTS: The faunaof the Santa Maria Basinand westem Santa BarbaraChannel isevaluated

fromsamplesthatwere takenfrom depthsof about50 to 1,000 m. Organismswere collectedfromsoft

sedimentsusingboxcoresandfromrocksusingmanipulatorarmsof submersiblesand remotelyoperated

I vehicles. The collectionsare organizedinto sets of vouchersfrom Phase I and II that have been made availableto the team of investigators. Additional material from the bulk collections now archived with the

Natural HistoryMuseumof LosAngeles County isalsobeing examined. Thetotal number of speciestreated

I in theentire TaxonomicAtlas (14volumes) mayexceed 1,300species.

A totalof 69 generaand42 familiesare treatedas part of Volume8. The scopeof thisvolumeincludes

i materialsfrom the MMS surveysaswell as additionalmaterialfrom the eastern Pacificaccumulatedby the authors. The authors have also examined most type specimens for each species and have produced a

monographthat willbe applicableto the entire marineenvironmentof western NorthAmerica. Inthis regard,

this volume becomes the most importantcompilationon northeastern Pacific non-gastropod mollusks inthe

I contribu last century, tion,inthiparticular s study iswitha valuable the bivalves contand ribution aplacophorans. to understandIniaddition, ng the distribution to beinganandimportant zoogeography taxonomicof

aplacophorans,chitons, scaphopods,bivalves, and cephalopods in the easternPacific. The rangesof many

I species are extended. Ninenew species are heredescribedfor the first time.

STUDY PRODUCT: Scott, P. H. and J. A. Blake(Editors). 1996. TaxonomicAtlasof the Benthic Fauna of

the SantaMaria BasinandWestern Santa BarbaraChannel.Volume 8. The MolluscaPart 1-- Aplacophora,

I Polyplacophora,Scaphopoda,Bivalvia,and Cephalopoda. A final reportpreparedby Science Applications International Corporation,for the U.S. Department of the Interior, Minerals Management Service, Pacific

OCS Region, Camarillo, CA. OCS Study MMS 96-0045. Contract No. 14-35-0001-30484.

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I "P.I'saffiliationmaybe differentthanthatlistedfor ProjectManager(s).
I

KEY MAP

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SouthernCaliforniaPlanningAreaIndicatingthe TaxonomicAtlas StudyRegion.

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I
REPORT DOCUMENTATION 1. e[|,owr NO. MMS 96-0045 =" =. I_clpam¢'_=, c,=,_o. PAGE

4. _ ,,.d s,._., s. _,po,t o._

Taxonomic Atlas of the Santa Maria Basin and Western Santa Barbara Channel. Volume July 1996

8, The Mollusca Part 1-- Aplacophora, Polyplacophora, Scaphopoda, Bivalvia, and ;_

Cephalopoda.

7. Author(s) 8, Perforrninl Orlianizatimq Rept, No,

Paul H. Scott and James A. Blake (editors)

9. Per_rmir_ OrlPln_zation Name and Address 10. Project/"l'lsk/Work Unit No.

Science Applications International Corporation 11.co,t,-==¢_=, o,_,_ No.

10260 Campus Point Drive

San Diego, California 92121 (c) 14-35-001-30484

(G)

12. Sponsoring Orlanlzltion Nlml and Address 13L Type of Report & Period Covered

Final 8 of 14 volumes,

Mineral Management Service, U. S. Department of the Interior, 9/89 to 7/96

Pacific OCS Region, 770 Paseo Camarilto .

Camarillo, California 93010 14.

15. SuDplermentlry Notes

Contributing authors: Dr. Eugene V. Coan, Dr. Douglas J. Eernisse, Dr. F. G. Hochberg, Dr. Am_lie H. Scheltema,

Mr. Paul H. Scott, Dr. Ronald L. Shimek.

lfh Abstract (L|mlt: 200 words)

A total of 69 genera and 42 families are treated as part of Volume 8. The scope of this volume includes materials from

the MMS surveys as well as additional material from the eastern Pacific accumulated by the authors. The authors have

also examined most type specimens for each species and have produced a monograph that will be applicable to the

entire marine environment of western North America. In this regard, this volume becomes the most important compilation

on northeastern Pacific non-gastropod mollusks in the last century, in particular with the bivalves and aplacophorans. In

addition, to being an important taxonomic contribution, this study is a valuable contribution to understanding the distribution

and zoogeography of aplacophorans, chitons, scaphopods, bivalves, and cephalopods in the eastern Pacific. The

ranges of many species are extended. Nine new species are here described for the first time.

17. Doc=mer, t Ans|ysls u. _r_

Marine invertebrates, Mollusca,Aplacophora, Polyplacophora, Scaphopoda, Bivalvia, Cephalopoda, taxonomy, California,

Santa Maria Basin, Santa Barbara Channel, continental shelf.

b. Identtfle_/Open-Ended Terms

Taxonomic Atlas, Keys to species, faunal guide, marine ecology, Mollusca, chitons, clams, tusk shells, octopus,

squids, marine benthos.

C. COSATI Field/Group

11L A'velTabitity _b1[ataument 19. Security Class (This Report) 21. No. of Pages

U nlimited Unclassified 238

_0, Security Cla_. (This PaLe) "Y). Price

See ANSI-7-39.183 See Instructions on Reverse OPTIONAL FORM 272 (4-7/_

(Formerly NTI S--35)

i Depsrtrr_t of Commecce
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Table of Contents |

1. INTRODUCTIONTOTHEMOLLUSCA(by Eugene V. Coan) i

General References on the Mollusca ............................................................................................... 2

2. CLASSAI'LACOPnORA(by Am61ie H. Scheltcma) i

Introduction ..................................................................................................................................... 3

Reproduction and Development ...................................................................................................... 4 i

Phylogeny ........................................................................................................................................ 4

Habitat and Behavior ....................................................................................................................... 4 n

Aplacophora of the Santa Maria Basin and Santa Barbara Channel ............................................... 4 1

External and Hard-part Morphology ............................................................................................... 5

Collection and Preservation ............................................................................................................ 6

Laboratory Methods ........................................................................................................................ 8 i

List of Species ................................................................................................................................. 9

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Abbreviations Used in the Figures ................................................................................................ 10

Key to the Species of Aplacophora in the Santa Maria Basin, Santa Barbara ChanneI, and Southern ll

California Bight ................................................................................................................ 10

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Descriptions of Species ................................................................................................................. 12 1

Family Gymnomeniidae ................................................................................................... 12 i

?Gymnomenia minuta Seheltema, new species .................................. 12

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?Genitoconia mariensis Scheltema, new species ................................ 14

Family Dondersiidae ........................................................................................................ 14 i

Heathia porosa (Heath, 1911) ............................................................... 14 I1

?Nematomenia sp................................................................................... 16

Neomeniomorpha sp............................................................................... 16 i

Family Limifossoridae ..................................................................................................... 18 II

Limifossor fratuIa Heath, 1911 .............................................................. 18

Family Chaetodermatidae ................................................................................................ 20 i

Crystallophrisson MiSbius, 1875. Ivanov, 1981..................................... 20 i

Chaetoderma argenteum Heath, 1911 ................................................... 20

Chaetoderma californicum Heath, 1911 ................................................ 22 ]l

Chaetoderma elegans Scheltema, new species ...................................... 24

Chaetoderma hancocki (Schwabl, 1963) ............................................... 26

Chaetoderma marinelli (Schwabl, 1963) ............................................... 28 i

Chaetoderma nanulum Heath, 1911 ...................................................... 30

Chaetoderma pacificum (Schwabl, 1963) .............................................. 32

Chaetoderma scabrum Heath, 1911 ....................................................... 34 I

Falcidens hartmanae (Schwabl, 1961) .................................................. 36

Falcidens longus Scheltema, new species ........................................... 38

Falcidens macracanthos Scheltema, new species ............................... 40 i

Furcillidens incrassatus (Schwabl, 1963), new combination .............. 42 n

Family Prochaetodermatidae ............................................................................................ 42

Spathoderma californicum (Schwabl, 1963) ......................................... 44 •

Literature Cited ............................................................................................................................. 46 1

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I 3. CLASSPOLXa'LACOPnOgA(by Douglas J. Eernisse)

Introduction ................................................................................................................................... 49

I Observing External and Internal Features 52 Systematic Treatment for Polyplacophora .................................................................................... 53

Glossary ......................................................................................................................................... 54

I Taxa Treated in This Atlas ............................................................................................................ 56 Key to the Polyplacopborans of the Santa Maria Basin ................................................................ 56

Descriptions of Species ................................................................................................................. 60

I Family Leptochitonidae Dall, 1889 .................................................................................. 60 Leptochiton rugatus (Carpenter in Pilsbry, 1892) ................................. 60

Hanleyella oldroydi (Bartsch MS, Dall, 1919) ...................................... 62

I SuborderFamily Ischnochit Ischnochitonidae onina Bergenhayn, Dalt, 1889 1930 ............................................................................................................................................................... 6464

Subfamily Ischnochitoninae Dall, 1889 ........................................................................... 64

I Lep Lepidozona idozona scabricostata retiporosa (Carpenter, (Carpenter,I864) 1864) .............................................. ......................................... 6664

Subfamily Callistoplacinae Pilsbry, 1893 ........................................................................ 67

I Family MopaliidaeCallistochiton Dall, 1889 palmuIatus ......................................................................................... Carpenter MS, Dall, 1879 ............................ 678

Mopaliaphorminx Berry, 1919 .............................................................. 68

I Ackn Literature owledgements Cited .................................................................................................................................................................................................................................................... 6971

4. CLASSSCAPItOPODA(by Ronald L. Shimek)

I Introduction ................................................................................................................................... 75

Systematic Treatment for the Santa Mafia Basin Area ................................................................. 77

I Taxa GlossaryTreated ......................................................................................................................................... 78 in This Atlas ............................................................................................................ 79

Key to the Scaphopods of the Santa Maria Basin ......................................................................... 79

i Des Ordercriptions Dentaliida of Species DaCosta,................................................................................................................. 81

1834 ................................................................................................... 82

Family Rhabdidae Chistikov, 1975 .................................................................................. 82

i Family DentaliidaeRhabdus Gray, rectius 1834 ........................................................................................ (Carpenter, 1864) ........................................................ 8284

Dentalium vallicolens Raymond, 1904 .................................................. 84

I Order Gadilida Starobogatov, 1977 .............................................................................................. 86 Family Gadilidae Stoliczka, 1868 .................................................................................... 86

Cadulus tolmiei Dall, 1897 .................................................................... 86

GadiIa aberrans (Whiteaves, 1887) ....................................................... 88

I Siphonodentalium quadrifissatum (Pilsbry and Sharp, 1898) ............... 90

Family Pulsellidae Scarabino, 1982 ................................................................................. 91

Acknowledgements ....................................................................................................................... 91

I Literature Cited .............................................................................................................................

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5. CLASSBIVALVlA(by Paul H. Scott) •

Introduction ................................................................................................................................... 97

Glossary ......................................................................................................................................... 98 1

Key to the Superfamilies ............................................................................................................. 102

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Subclass Palaeotaxodonta Korobkov, 1954 ................................................................................ 105

OrderNuculoida Dall, 1889 ........................................................................................................ 105 l

Superfamily Nuculoidea J. E. Gray, 1824 ............................................................................ 105

Family Nuculidae J. E. Gray, 1824 ................................................................................ 105

Nucula carlottensis Dall, 1897 ............................................................. 106 il

Eunnucula tenuis (Montagu, 1808) ..................................................... 107

Eunnucula cardara (Dall, 1916) .......................................................... 108

Acila castrensis (Hinds, 1843) ............................................................. 109 i

OrderSolemyida Dall, 1889 ........................................................................................................ 110 i

Superfamily Solemyoidea J. E. Gray, 1840 .......................................................................... 110

Family Solemyidae J. E. Gray, 1840 .............................................................................. 110 Ii

Solemya reidi F. R. Bernard, 1980 ....................................................... 111

Superfamily Manzanelloidea Chronic, 1952 ........................................................................ 112

Family Manzanellidae Chronic, 1952 ............................................................................ t 12 •

Huxleyia munita (Dall, 1898) ............................................................... 113

Superfamily Nuclanoidea H. Adams & A. Adams, 1858 ..................................................... 114

Family Nuculanidae H. Adams & A. Adams, 1858 ....................................................... 114 •

NucuIana leonina (Dall, 1896) ............................................................. 115

Nuculana hamata (Carpenter, 1864) .................................................... 116

Nuculana conceptionis (Dall, 1896) .................................................... 116 i

Nuculana taphria (Dall, 1896) ............................................................. 117 1

Nuculana pontonia (Dall, 1890) .......................................................... 118

Family Tindariidae Scarlato & Starobogatov, 1971 ...................................................... 119 •

Tindaria kennerlyi (Dall, 1897) ........................................................... 120 n

Family Neilonellidae J. A. Alien, 1978 .......................................................................... 121

Neilonella ritteri (DaU, 1916) .............................................................. 122 I

Family Sareptidae Stoliczka, 1871 ................................................................................. 122 l

Yoldia seminuda Dall, 1871 ................................................................. 123

Subclass Pteriomorphia Beurlen, 1944 ....................................................................................... 124 •

Order Mytiloida F6rassac, 1822 .................................................................................................. 124 I

Superfamily Mytiloidea Rafinesque, 1815 ........................................................................... 124

Family Mytilidae Rafinesque, 1815 ............................................................................... 125 I

Modiolus neglectus Soot-Ryen, 1955 .................................................. 126 I

Amygdalum paIlidulum (Dall, 1916) .................................................... 126

CreneIla decussata (Montagu, 1808) ................................................... 128 I

Solamen columbianum (DaI1, 1897) ..................................................... 129 i

Gregariella coarctata (Carpenter, 1857) ............................................. 130

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Order Limoida Waller, 1978 ....................................................................................................... 130 m

Superfamily Limoidea Rafinesque, 1815 ............................................................................. 131 I!

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Family Limidae Raf'mesque, 1815 ................................................................................. 131

Limatula saturna F. R. Bernard, 1978 ................................................. 132

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I Order Osteroida F6mssac, 1822 .................................................................................................. 132

Superfamily Pectinoidea Rafinesque, 1815 .......................................................................... 133

i Family PectinidaeChlamys Rafmesque, 1815 .............................................................................. 133 hastata (G. B. Sowerby II, 1842) .......................................... 134

Leptopecten latiauratus (Conrad, 1837) .............................................. 136

i Delectopecten vancouverensis (Whiteaves, 1893) .............................. 137

Subclass Heterodonta .................................................................................................................. 138

Family Lucinidae Fleming, 1828 ................................................................................... 138

Parvilucina tenuisculpta (Carpenter, 1864) ......................................... 139

n Lucinoma annulams (Reeve, 1850) ..................................................... 140

Family Thyasiridae Dall, 1900 [1895] ........................................................................... 140

Thyasiraflexuosa (Montagu, 1803) ..................................................... 141

I Axinodon redondoensis Burch, 143

(T. 1941)

Axinopsida suborbicularis (A. Adams, 1862) ..................................... 144

Adontorhina cycIia Berry, 1947 ........................................................... 145

I Superfamily Carditoidea Fleming, 1828 146 Family Carditidae Fleming, 1828 .................................................................................. 146

Cyclocardia ventricosa (Gould, 1850) ................................................. 146

I Cyclocardia barbarensis (Stearns, 1890) 147 Superfamily Chamoidea Lamarck, 1809 .............................................................................. 148

Family Charnidae Blainville, 1825 ................................................................................ 148

I Chama arcana Bernard, 1976 149 Pseudochama exogyra (Conrad, 1837) ................................................ 150

Superfamily Galeommatoidea J. E. Gray, 1840 ................................................................... 151

I Family Galeommatidae J. E. Gray, 1840 ....................................................................... 151 New Genus, New Species A ................................................................ 151

Family Lasaeidae J. E. Gray, 1842 ................................................................................. 152

I Rochefortia compressa Dall, 1913 ....................................................... 153 Rochefortia grippi Dall, 1912 .............................................................. 154

Rochefortia tumida (Carpenter, 1864) ................................................. 155

I Rochefort Rochefortiaia sp. A ................................................................................. 156 sp. B .................................................................................. 156

Rochefortia sp. C .................................................................................. 157

I Superfamily Family Cardiidae CardioideaLamarck, Lamarck,18091809.................................................................................................................................................................. 158 158

Nemocardium centifilosum (Carpenter, 1864) ..................................... 159

I Superfamily Family Veneridae VeneroideaRaf'mesque, Raf'mesque,18151815.............................................................................. .......................................................................... 159 159

Compsomyax subdiaphana (Carpenter, 1864) ..................................... 160

I Superfamily Family Tellinidae TellinoideaBlainville, Blainville,1814814................................................................................ ............................................................................ 161 161

Tellina modesta (Carpenter, 1864) ....................................................... 161

I Macoma Tellina carpenteri yoldiformisDall, Carpenter, 1900 ............................................................... 1864 .................................................. 1623

Macoma carlottensis Whiteaves, 1880 ................................................ 164

I Family Bernardinidae Halodakra Keen,salmonea 1969 ................................................................................. (Carpenter, 1864) ............................................... 164 165

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Order Myoida Goldfuss, 1820 ..................................................................................................... 165 •

Superfamily Hiatelloidea J. E. Gray, 1824 ........................................................................... 165

Family Hiatellidae J. E. Gray, 1824 ............................................................................... 166 •

Hiatella arctica (Linnaeus, 1767) ........................................................ 166 I

Saxicavella nybakkeni P. H. Scott, 1994 .............................................. 168

SaxicaveUa pacifica Dall, 1916 ........................................................... 168 il

Subclass Anomalodesmata Dall, 1889 ........................................................................................ 169 |

Order Pholadomyoida Newell, 1965 ........................................................................................... 169

Superfamily Pandomidea Rafinesque, 1815 ......................................................................... 169 In

Family Pandoridae Rafinesque, 1815 ............................................................................ 170 I

Pandora biIirata Conrad, 1855 ............................................................ 170

Family Lyonsiidae Fischer, 1887 ................................................................................... 171 m

Lyonsia californica Conrad, 1837 ........................................................ 171 •

Superfamily Thracioidea Stoliczka, 1870 [1830] ................................................................. 172

Family Thraciidae Stoliczka, 1870 [1830] ..................................................................... 172 m

Thracia trapezoides Conrad, 1849 ....................................................... 173 ]]

Family Periplomatidae Dall, 1895 ................................................................................. 174

m

Periploma discus Stearns, 1890 ........................................................... 174

Superfamily Verticordioidea Stoliczka, 1871 ...................................................................... 175

Family Verticordiidae Stoliczka, 1871 .......................................................................... 175 w

Dalliocordia alaskana (Dall, 1895) ..................................................... 175

Order Septebranchida Pelseneer, 1888 ........................................................................................ 176 •

Superfamily Cuspidarioidea Dall, 1886 ............................................................................... 176 m

Family Cuspidariidae Dall, 1886 ................................................................................... 177 I

Cuspidariaparapodema F. R. Bernard, 1969 ...................................... 177

Cardiomya pectinata (Carpenter, 1864) .............................................. 178 II

Acknowledgements ..................................................................................................................... 179

Literature Cited ........................................................................................................................... 180 I

6. CLASSCV_,VnALOVOI)(by A F.G. Hochberg)

Introduction ................................................................................................................................. 189 I

Collection and Preservation ........................................................................................................ 190

Laboratory Study ......................................................................................................................... 191

Terms for Measurements and Counts ......................................................................................... 191 •

Indices ......................................................................................................................................... 192

Glossary ....................................................................................................................................... 193

Key to the Orders of Cephalopoda .............................................................................................. 197 •

List of Species ............................................................................................................................. 197

Description of Species ................................................................................................................. 198

Family Sepiolidae Leach 1817 ....................................................................................... 198 •

Subfamily Rossinae Appelloff 1898 .............................................................................. 198

Rossia pacifica Berry, 1911 ................................................................. 198

Family Loliginidae d'Orbigny, 1848 ............................................................................. 203 •

Loligo opalescens Berry, 1911 ............................................................. 203 !1

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I Order Octopoda Leach, 1818

Key to Species of Octopoda ........................................................................................................ 207

i Family Octopodidae Orbigny, 1840 ............................................................................... 207 Subfamily Bathypolypodinae Robson, 1928 .................................................................. 207

Benthoctopus leioderma (Berry, 1911) new combination ................... 208

Benthoctopus robustus Voss and Pearcy, 1990 ................................... 210

I Subfamily Graneledoninae Voss 1988 ........................................................................... 212

Graneledone boreopacifica Nesis, 1982 .............................................. 213

Subfamily Octopodinae .................................................................................................. 216

I Octopus dofleini Wtilker, 1910 ............................................................ 216

Octopus rubescens Berry, 1953 ........................................................... 219

Octopus californicus Berry, 1911 ........................................................ 222

I Acknowledgments ....................................................................................................................... 225 Literature Cited ........................................................................................................................... 225

I Avv_ro_ ................................................................................................................................................... 233

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List of Figures i

Figure 2.1. Spicule morphology: A, crystallographer's interference color chart showing birefringence i

of aragonite under cross-polarized hght (diagonal line), thickness (ordinate), and colors

(abscissa). The highest order of color for a spicule is determined when all light is extinguished i

except that passing through the spicule, starting at the black edge of spicule. The greatest 1

thickness is illustrated in B by stippling. An isochrome between any two color bands is

indicated by a dotted line and shows the pattern consequent upon varying thicknesses in the Hi

spicule. The base and blade of a spicule may or may not be set apart by an ill-def'med 1

waist. A spicule may be sculptured by a keel, indicated by a double line, or by ridges,

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shown with a single line ..................................................................................................... 7

Figure 2.2. ?Gymnomenia minuta Scheltema, new species: A, B, holotype (NMNH), lateral and ventral II

views, anterior to left; C, ventral view of paratype (LACM) showing mouth/vestibule opening

andpedal pit; D, E, holotype spicules from body (D) and ventral furrow (E); F, two copulatory •

spicules, proximal ends eroded, from a bundle of about twelve, specimen C; radula tooth,

base not seen, from paratype (LACM) ............................................................................. 13

Figure 2.3. ?Genitoconia mariae Scheltema, new species: A, holotype (NMNH), dorsal view, anterior 1

to right; the drawing does not do justice to the shining, glossy coat of spicules; 13,paratype,

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posterior end, lateral view (LACM); C, anterior end of A, ventral view; D, several copulatory

spicules from B, proximal ends to left probably eroded; E, short-pointed spicules; F, spicules D

from foot furrow; G, long-pointed spicule; H, radula teeth from two different views .... 15

Figure 2.4. lchthyomenia (= Heathia) porosa Heath: A, figure from Heath, 1911, plate 3, fig. 4; B-D, •

holotype spicules from body (B), foot-furrow (C), and lateral to foot-furrow (D) ......... 16

Figure 2.5. ?Nematomenia sp.: A, B, posterior and anterior ends, respectively, in lateral view showing 1

dorsal caxina, spicules not indicated; C, D, lateral and frontal views of spicules ............ 17 i

Figure 2.6. Neomeniomorpha sp.: A, entire specimen, anterior to left; B, C, ventral view of anterior

and posterior ends, respectively; D, spicules of body ...................................................... 17 1

Figure 2.7. Limifossorfratula Heath: A, specimen from Santa Maria Basin (NMNH); B, C, radula of

A, dorsal 03) and frontal (C) view; D, E, G, spicules of A from dorso-anterior body (D), I

mid-dorsal trunk (E), and midventral trunk (G); F, spicule from syntype (CAS). Longitudinal i

lines here indicate grooves, not ridges ............................................................................. 19 I

Figure 2.8. Chaetoderma argenteum Heath: A, specimen from Santa Maria Basin (NMNH); B, oral •

shield of presumed syntype of C. montereyensis (MCZ); C, posterium of specimen A; D-H, l

spicules of specimen B, from neck (D), anterior trunk at constriction (E, F), posterior region

of anterior trunk (G), and mid-posterior trunk (H); J, K, radula of specimen A, frontal view •

(J) and lateral view of cone (K), frontal to right .............................................................. 21 I

Figure 2.9. Chaetoderma californicum Heath: A, specimen from Santa Maria Basin (NMNH); B, oral

shield of A; C, posterium of A; D, radula reconstructed from holotype sections (CAS); E, I

G, J, spicules of specimen A, from neck (E), anterior trunk at constriction (G, lateral view g

above), and mid-posterior trunk (J); F, H, spicules from anterior (F) and posterior (H) trunk

of holotype ........................................................................................................................ 23 i

II

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I Figure 2.10. Chaetoderma elegans Scheltema, new species: A, holotype (LACM 00000); B, oral shield

of paratype (NMNH); C, posterium of A; D-G, spicules of holotype from neck (D), anterior

i trunk at constriction (E), mid-anterior trunk (F), and mid-posterior trunk (G): H, J, radula of paratype, lateral view of cone (H), frontal to left, and frontal view (J) (cone broke after

drawing H) ........................................................................................................................ 25

I Figure 2.11. Chaetoderma hancocki (Schwabl): A, specimen from San Pedro Basin (BLM-LACM Sta. 827), deep constriction between anterium and neck indicated by arrow; B, C, oral shield of

specimen A 03) and lectotype (C, LACM 2093); D, E, posterium of lectotype (D) and

I frontal specimenviewA (E); (F) andF, G,lateral radulaviewof specimen of cone (G), fromfrontal San Pedro to right;BaH-O, sin (BLM-LACM spicules of specimen Sta. 821),A

(H-L, O) and lectotype of Cr. inflatum (M, N) from neck (type 1, H, type 2, J), anterior

I trunk (type 1, K, type 2, L) and posterior trunk (type 1, M, type 2, N, O) ...................... 27

Figure 2.12. Chaetoderma marinelli (Schwabl): A, specimen from offSan Diego (LACM); B, posterium

of specimen A; C, oral shield of lectotype (LACM 2099); A, entire specimen; B, posterium

I showing dorsoterminal C, oral shieldof 2099); D-J,

sense organ (black); lectotype (LACM

spicules of lectotype (E-G) and specimen A (D, H, J) from neck (D, E), anterior trunk at

constriction (F, H), and mid-posterior trunk (G, J), posterior trunk spicules slightly oblique

I showing curve towards body; K, L, radula of specimen A, frontal view (K) and lateral view, frontal to right, broken at base (L) ................................................................................... 29

I Figure 2.13. B, Chaet small oderma individual nanuIumfromHeath: Santa A, Barbara specimenBasinfrom(NMNH); San PedrC, o Baoral sinshield (BLM-LA of large CM individual Sta. 825);

from Santa Barbara Basin (NMNH); D, posterium of specimen A showing dorsoterminal

I strunk ense from: organ holotype (stippling);(F,E,CAS), neck specimen spicule ofAlarge (G),individual; specimen fromF-H, south type 1ofspicules Santa Cruz of anteIsland rior

(H), and 44-mm individual (Sta. R-7, NMNH)(J); K, L, type 2 spicules of anterior trunk

i frO,om holotype (K) and 44-mm individual(L); M, posterior trunk spicule from holotype; N, frontal and lateral views of radula of specimen from south of Santa Cruz Island (BLMLACM Sta. 227) ............................................................................................................... 31

I Figure 2.14. Chaetoderma pacificum (Schwabl): A-H, specimen, from Santa Maria Basin (NMNH). A,

entire specimen; B, posterium, mantle cavity open and ctenidia extended, dorsoterminal

sense organ black; C, oral shield; D, frontal view of radula; E, lateral view of radula cone,

I frontal to left, base broken; F-H, spicules from neck (F), anterior trunk at constriction (G), and mid-posterior trunk (H) ............................................................................................. 33

i Figure 2.15. Chaet Sta. 842); odermaB, oral scabrum shield,Heath: individual A, indi fromvidual Sann

Pedro orthwest Basin; of SanC, Nposte icolriasumIsland of A;(BD-J, LM-LACM spicules

from neck (D), anterior trunk near constriction type 1 (E) and type 2 (F), mid-anterior trunk

i (G, H), and mid-posterior trunk (J), all from individual A except spicule G from holotype; K, L, frontal and lateral views of radula of individual A, front of radula cone to right in L

...... • ................................................................................................................................... 35

I Figure 2.16. Falcidens hartmanae: A, specimen from Santa Maria Basin (NMNH); B, oral shield of specimen A; C, D, E, radula of specimens from, respectively, Southern California Bight,

San Diego Trough, and Santa Barbara Basin (NMNH); denticles and triangular plate broken);

I Fupper, -H, spiJ cfrom ules from specimen anteriA;umG (F), lowerneckleft(from G), trunk San Diego (H), andTroposterium ugh; G, H,(J);lower F, Grighupper, t, fromH

Southern California Bight ................................................................................................ 37

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Figure 2.17. Falcidens longus Scheltema, new species: A, holotype (NMNH); B, oral shield of specimen I

A; C, neck region of specimen A; C, posterium of specimen A; F-J, spicules from neck (F),

anterior trunk at constriction (G), mid-anterior trunk (H), and mid-posterior trunk (J), F •

right, G left from paratype, rest of spicules from holotype; K, frontal view and L, lateral |

view of radula (paratype, LACM) .................................................................................... 39

Figure 2.18. Falcidens macracanthos Scheltema, new species: A, holotype (NMNH 000000; B, C, II

posterior mantle cavity wall and oral shield, respectively, of specimen A; D-F, spicules of i

paratype no. 1 (NMNH) from neck (E), anterior trunk (F), and mid-posterior trunk (D),

spicule F at right same as spicule to left, greatly reduced, showing pattern of thickening; G, II

abfrontal view of radula of small specimen 5.4 mm long (paratype no. 3, NMNH) showing I!

triangular plate; H, spicule of same specimen as G; J, K, frontal and lateral views of radula

of paratype no. 2 (NMNH) (drawn at smaller scale than G) ........................................... 41 1

i

Figure 2.19. Furcillidens incrassatus (Schwabl): A, specimen from BLM-LACM Sta. 803; B, oral shield,

specimen (SMB Ph. I Sta. 99, NMNH); C, D, radula, frontal and lateral views, respectively, I

sclerotized portions stippled (SMB Ph. I Sta. 91, NMNI-I); E, F, neck spicules; G, H, anterior i

trunk spicules; J, posterior trunk spicule; D, F, H, J, (SMB Sta. 91); E, G, lectotype (LACM)

mR

............. ...... ....................................................................... .................... ............................ 43

Figure 2.20. Spathoderma californicum (Schwabl): A, paralectotype (LACM 2092), spicules dissolved, U

jaws evident through cuticle; B, C, specimen in ventral (B) and dorsal (C) view (SMB Ph.

I Sta. 62, NMNH); D-G, radula apparatus of paralectotype; D, distal and proximal ends of i

two teeth; E, central plate; F, G, jaws in side and medial views; H-M, spicules of specimen

B, C; H from dorso-anterior, J from mid-dorsal trunk, K, L from region between trunk and

posterium, M from midventral trunk ................................................................................ 45 •

Figure 3.1. External anatomy of chitons, from Eernisse and Reynolds (1994). Figures oriented with

anterior end at the top. A. Dorsal view of Chiton tuberculatus (Ischnochitonina: Chitonidae). ms

C, central area (note the anterior portion of tail valve with same sculpturing pattern); g, i

girdle elements (overlapping scales in this case); h, head valve; j, jugum and jugal area; l, i

lateral area (note head valve and posterior part of tail valve have similar sculpturing); t, tail i

valve. B. Ventral view of disarticutated valves of Chiton squamosus, a, apophyses; ip, II

insertion plates; js, jugal sinus; s, slit in insertion plate of articulamentum shell layer. C. I

Ventral view of Ferreirella caribbeanensis (Lepidopleurina: Leptochitonidae). Note

posterior placement of gill rows, which are adanal (most posterior gill in each row is not the H

largest) and without interspace. D. Ventral view of Chiton bowenii. Gill rows are adanal i

with interspace, f, foot; g, ventral side of girdle; gr, left gill row; m, mouth and oral platform.

E. Ventral view of Mopalia hindsii (Ischnochitonina: Mopaliidae). Gill rows are abanal

(most posterior gill in each row is largest) with interspace. Scale bars: A, B = 5.5 mm; C-E

= 1 cm ............................................................................................................................... 50

i

Figure 3.2. Leptochiton rugatus (Carpenter in Pilsbry, 1892). Dorsal view of specimen, 6 mm length, U

from Bahia San Luis Gonzaga, Baja California, Mexico ................................................. 61

Figure 3.3. HanIeyella oldroydi (Bartsch MS, DaU, 1919). Dorsal view of specimen, 4 mm length, i

dredged off Ensenada, Baja California, Mexico .............................................................. 63 g

Figure 3.4. Lepidozona scabricostata, specimen (18 mm length) dredged by fishermen from 340 m on •

coral, off Carlsbad, California: A, dorsal view; B, head valve region; C, tail valve region; 1

D, lateral areas of intermediate valves and girdle ............................................................ 65

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I Figure 3.5. Lepidozona retiporosa, specimen (8 mm length) dredged by fishermen from 340 m on

coral, off Carlsbad, California: A, tail valve region; B, lateral dorsal view .................... 67

I Figure 3.6. Mopalia phorminx, specimen from Gulf of Alaska, 10 mm length: A, dorsal view of specimen; B, close-up of tail valve region; C, lateral areas of intermediate valves; D, head

valve region. Mopalia imporcata, specimens from Port Gamble, Washington: E, dorsal

I view G, of specimen of I 1mm length; F, close-up of tail valve region of 17 mm long specimen; lateral areas of intermediate valves of same specimen as F; H, head valve region of same

specimen as F ................................................................................................................... 70

I Figure 4.1. Semi-diagrammatic illustration of a dentaliid scaphopod with the shell removed, and the

mantle reflected as if cut with a scalpel. Major organs and structures are labelled. A =

Anus; BP = Buccal Pouch; C = Captacula; CG = Cerebral Ganglia; DG = Digestive Gland;

I F = Foot; G = Gonad; N = Nephridium; R = Radula; RR = Respiratory Ridges .............

75

Figure 4.2. Generalized Scaphopods. A. Dentaliid scaphopod with the foot extended and the epipodial

I lo........................................................................................................... bes extended; B. Gaditid scaphopod with the foot extended, note the.......... foot'..................... s terminal disc76

Figure 4.3. Rhabdus rectius (Carpenter, 1864) .................................................................................. 83

I Figure 4.4. Dentalium vallicolens Raymond 1904. A. Entire shell. B. Dorsal shell apex showing

longitudinal fibs. C. Dorsal shell apex, apical view showing longitudinal ribs ............... 85

I Figure 4.5. CaduIus tolmiei DalI, 1897 ............................................................................................... 87

Figure 4.6. GadiIa aberrans (Whiteaves, 1887) ................................................................................. 89

I Figure 4.7. Siphonodentalium quadrifissamm (Whiteaves, 1887) ..................................................... 90

Figure 5.1. Nucula carlottensis: A, interior of left valve; B, exterior of left valve .......................... 106

I Figure 5.2. Ennucula tenuis: A, exterior of fight valve; B, interior of left valve ............................. 107

Figure 5.3. Ennucula cardara: A, exterior of right valve; B, interior of left valve ......................... 108

I Figure 5.4. Acila castreneis: A, exterior of right valve; B, interior of left valve; C, dordal view of both

valves .............................................................................................................................. 109

I Figure 5.5. Solemya reidi: exterior of fight valve ............................................................................. 111

Figure 5.6. HuxIeyia munita: A, exterior of fight valve; B, interior of left valve; C, dorsal view of both

valves .............................................................................................................................. 113

I Figure 5.7. NucuIana leonina: A, exterior of fight valve; B, interior of left valve; C, dorsal view of both

valves .............................................................................................................................. 115

I Figure 5.8. Nuculana hamata: A, exterior of fight valve; B, dorsal view of both valves ................ 116

Figure 5.9. Nuculana conceptionis: A, exterior of right valve; B, interior of left valve; C, dorsal view of

I both valves ...................................................................................................................... 117

Figure 5.10. Nuculana taphria: A, exterior of right valve; B, interior of left valve; C, dorsal view of both

valves .............................................................................................................................. 118

I Figure 5.11. Nuculana pontonia: A, exterior of right valve; B, interior of left valve; C, dorsal view of

both valves ...................................................................................................................... 119

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I

Figure 5.12. Tindaria kennerleyi: A, exterior of left valve; B, interior of right valve ....................... 120 I

Figure 5.13. Neilonella ritteri: A, interior of right valve; B, exterior of left valve ............................ 122

Figure 5.14. Yoldia seminuda: A, exterior of left valve; B, interior of right valve; C, dorsal view of both I

valves .............................................................................................................................. 123

Figure 5.15. Modiolus neglectus: A, exterior of left valve; B, interior of right valve ....................... 127 I

Figure 5.16. Amygdalum pallidulum: A, exterior of left valve; B, interior of right valve ................. I27

Figure 5.17. Crenella decussata: A, interior of left valve; B, exterior of left valve .......................... 128 I

Figure 5.18. Solamen coIumbianum: A, exterior of left valve; B, dorsal view of both valves .......... 129

Figure 5.19. Gregariella coarctata: A, exterior of left valve; B, interior of right valve ................... 130 I

Figure 5.20. LimatuIa saturna: A, exterior of left valve; B, interior of fight valve ........................... 132

Figure 5.21. Chlamys hastata: A, exterior of right valve; B, exterior of left valve ........................... 135 I

Figure 5.22. Leptopecten latiauratus: A, exterior of right valve; B, exterior of left valve ................ 136

Figure 5.23. Delectopecten vancouverensis: A, exterior of right valve; B, exterior of left valve ..... 137 I

Figure 5.24. ParviIucina tenuiscuIpta: A, exterior of left valve; B, interior of right valve ............... 139

Figure 5.25. Lucinoma annulatus: A, exterior of left valve; B, interior of right valve ...................... 140 I

Figure 5.26. Thyasira flexuousa: A, exterior of right valve; B, details of hinge, left valve lower, right

valve above; C, dorsal view of both valves .................................................................... 142 I

Figure 5.27. Axinodon redondoensis: A, exterior of left valve; B, interior of right valve ................. 143

Figure 5.28. Axinopsida suborbicularis: A, exterior of left valve; B, interior of right valve ............ 144 I

Figure 5.29. Adontorhina cyclia: A, exterior of right valve; B, interior of right valve; C, dorsal view of

both valves ...................................................................................................................... 145

Figure 5.30. Cyclocardia ventricosa: A, exterior of left valve; B, interior of right valve ................. 147 I

Figure 5.31. Cyclocardia barbarensis: A, exterior of left valve; B, interior of fight valve ............... 148

Figure 532. Chama arcana: A, exterior of right valve; B, interior of left valve ............................... 149 I

Figure 5.33. Pseudochama exogyra: A, exterior of left valve; B, interior of right valve .................. 150

Figure 5.34. Galeommatidae new genus, new species A: A, interior of left valve; B, exterior of living I

animal from the left side ................................................................................................ 152

Figure 5.35. Rochefortia compressa: A, detail of hinge in right valve; 13,exterior of left valve ....... 154 I

Figure 5.36. Rochefortia grippi: A, detail of hinge in right valve; 13,exterior of left valve .............. 155

Figure 5.37. Rochefortia tumida: A, interior of right valve; B, exterior of left valve ........................ 156 I

Figure 5.38. Rochefortia sp A: A, detail of hinge in right valve; B, interior of right valve ............... 157

Figure 5.39. Rochefortia sp. B: A, interior of right valve; B, exterior of left valve ........................... 157 I

Figure 5.40. Rochefortia sp. C: A, interior of right valve; B, exterior of left valve ........................... 158

I

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I Figure 5.41. Nemocardium centifdosum: A, detail of hinge in right valve; B, exterior of left valve ...... 159

Figure 5.42. Compsomyax subdiaphana: A, exterior of left valve; B, interior of right valve ............ 160

I Figure 5.43. Tellina modesta: A, interior of right valve; B, interior of left valve .............................. 162

Figure 5.44. Tellina carpenteri: A, interior of right valve; B, interior of left valve .......................... 163

I Figure 5.45. Macoma yoldiformis: A, interior of right valve; B, interior of left valve ...................... 163

im Figure 5.46. Macoma carlottensis: A, interior of right valve; B, interior of left valve; C, posterior view

_: i of both valves ................................................................................................................. 164

Figure 5.47. Halodakra salmonea: A, hinge of left valve; B, hinge of right valve. (after Coan, 1984).

I ........................................................................................................................................ 165 Figure 5.48. Itiatella arctica: A, exterior of left valve; B, interior of left valve ............................... 167

I Figure 5.49. Saxicavella nybakkeni: A, dorsal view of living animal; B, lateral view of living animal. (after Scott, 1984) ........................................................................................................... 168

Figure 5.50. Saxicavella pacifica: A, exterior of left valve; B, interior of right valve ...................... 169

I Figure 5.51. Pandora bilirata: A, exterior of left valve; B, exterior of right valve ........................... 170

Figure 5.52. Lyonsia californica: A, interior of right valve; B, exterior of right valve ..................... 172

I Figure 5.53. Thracia trapezoides: A, exterior of left valve; B, interior of right valve ....................... 173

Figure 5.54. PeripIoma discus: A, exterior of left valve; B, interior of right valve ........................... 174

I Figure 5.55. Dalliocordia alaskana: A, exterior of valve; B, interior of right valve ......................... 176

Figure 5.56. Cuspidaria parapodema: A, exterior of left valve; B, interior of right valve ............... 178

I Figure 5.57. Cardiomya pectinata: A, exterior of left valve; B, interior of right valve ..................... 179

Figure 6.1 Rossia pacifica: A, ventral view; B, male - oral view of right arms. (after Berry, 1912a) ........

I ........................................................................................................................................ 202

Figure 6.2. Loligo opaIescens. A, dorsal view of mature male holotype (USNM); ventral view of

I mature male holotype (USNM); C, gladius of male (USNM). (after Berry, 1912a) ..... 205

Figure 6.3. Benthoctopus leioderma: lateral view of living animal. (after Berr, 1912a) ................. 209

I Figure 6.4. Benthoctopus B, ligula; C, digestive robustus:tract A, lateral of paratype view of(USNM holotype730895), (USNMmale, 729994), 49 mmmaleML;137D,mmcropML;of

holotype; E, crop of paratype; F, funnel organ of holotype; G, H, upper and lower beaks of

i _ holotype. (after Voss and Pearcy, 1990) ........................................................................ 211

i Figure 6.5. GraneIedone boreopacifica: lateral view of holotype, USNM 730716, male, 85 mm ML.

(after Voss and Pearcy, 1990) ........................................................................................ 215

I Figure 6.6. Octopus dofleini: view of living specimen. (from Morris, Abbott, and Haderlie, 1980) .... 218

Figure 6.7. Octopus rubescens: view of living specimen. (from Morris, Abbott, and Haderlie, 1980) .......

I ........................................................................................................................................ 221

Figure 6.8. Octopus californicus: A, ventral view of large male, San Diego, California; B, dorsal view

I of holotype specimen (male). (after Berry, 1912a) ........................................................ 223

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Acknowledgments I

This study was funded by the Pacific Outer Continental Shelf Region of the U.S. Department of the i

Interior, Minerals Management Service, Washington, D.C., under Contract No. 14-35-0001-30484. Ms.

Marie Murphy of the Santa Barbara Museum of Natural History provided graphic design and production 1

assistance for this volume. Ms. Adele Smith ass•ted with editing and production of this volume.

!

List of Acronyms i

i

ANSP Academy of Natural Sciences, Philadelphia, Pennsylvania, USA.

BLM Bureau of Land Management. B

BMNH The Natural History Museum, London, United Kingdom.

BRA Refers to a station designation from the MMS Phase I Reconnaissance: Benthic Rocky, i

transect A/B.

to a station designation from the MMS Phase I Reconnaissance: Benthic Rocky, 1

BRC Refers

transect C/D.

CAS California Academy of Sciences, Department of Invertebrate Zoology, San Francisco, i

California, USA.

ICZN International Code of Zoological Nomenclature. []

LACM Natural History Museum of Los Angeles County, Los Angeles, California, USA. i

MCZ Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA. n

MMS Minerals Management Service. i

SCAMIT Southern California Association of Marine Invertebrate Taxonomists. []

SBMNH Santa Barbara Museum of Natural History, Santa Barbara, California, USA. II

SDNHM San Diego Natural History Museum, San Diego, California, USA. am

USNM United States National Museum. A historical designation for the National Museum of i

Natural History (NMNH), Smithsonian Institution, Washington, D.C., USA.

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1. INTRODUCTION TO THE MOLLUSCA

II by

Eugene V. Coan I

I The living Mollusca are believed to be a monophyletic group of organisms that originated at least as

early asthe Lower Cambrian. Their shell-less ancestor was probably unsegmented and dorsoventrally flattened,

I and it lived in the ocean, scraping microorganisms offthe substratum for food. Differentiation of the Mollusca into distinct classes occurred so long ago and probably at least in part among shell-less ancestors that

relationships remain a topic of lively debate.

I Key features of the living Mollusca, although not each in all classes, include a hardened

present

calcium carbonate shell, a unique feeding apparatus called a radula, an otherwise soft body that has as its

external layer mantle tissue capable of secreting the shell, and a cavity invaginating the mantle that contains

I gills and openings to the digestive and reproductive systems.

The modern Mollusca are now divided into seven distinctive classes, each represented in the Santa

Maria Basin and the Santa Barbara Channel.

I The Aplaeophora are divided into two subclasses the Chaetodermomorpha and the Neomenimorpha.

The Chaetodel'momorpha are cylindrical, wormlike mollusks from 2-140 mm in length. They have a

I radula a posterior but nomantle shell,cavity insteadwithbeinga paircovered of bipectinate by a chitinous ctenidia. cuticle Theywithare embedded marine, mostly imbricating infaunalscales. burrowers Therethatis

feed on microorganisms and detritus. There are about 70 species.

I They areThe Neomeniomorpha are also wormlike, but are laterally compressed, with a ventral pedal groove. from 1-300 mm in length. Like the Chaetodermomorpha, they lack a shell, and only some have a

radula. Their outer surface is covered with a cuticle and scales or spicules. There is a posterior mantle cavity,

I which epizoiclacks on cnida a gillrians, but hupon as secondar whichytherespi y fered. atoryThere structures are abouin tsome. 180 species. They are marine and live on sediment or

The Polyplacophora, or chitons, are dorsoventrally flattened, elongate to ovate, from 3-400 mm in

I length. Their dorsal surface is covered by eight overlapping calcareous plates embedded in an encircling girdle. The girdle covers or almost covers the plates in a few species, and it is covered by spines, spicules or

bristles. There is a broad ventral foot, surrounded by a narrow encircling mantle cavity with 6-88 pairs of

I gills. species.They are mostly grazing herbivores on hard substrata using their radula. There are more than 800

The Monoplaeophora, are similar in shape to limpet gas_opods, but have not undergone torsion.

I There are eight pairs pedal muscles and 5-6 pairs of gills in the mantle cavity that surrounds the foot. These benthic marine animals make a living scraping substrata with their radula. There are as many as 20 living

species from 200 m to abyssal depths. A single species has been reported in about 300 m in southern California.

I Gastropoda, or snails, are by most common They occur through seas, as

The far the class. the well

as in fxeshwater and on land. A few marine taxa are entirely parasitic. They were primitively torted (the body

mass being twisted relative to the foot), resulting in bilateral asymmetry. There is generally a single shell,

I coiled in in several and the shell has become lost in different lineages. There

most, limpet-like groups, many

!

i t Department of Invertebrate Zoology Santa Barbara Museum of Natural History, 2559 Puesta del Sol Road, Santa Barbara, California 93105 USA
I

is a radula in most taxa, which has become specialized for various tasks in different groups. The foot of most •

is used for creeping, but it is specialized for swimming in a few. The mantle cavity, moved anteriorly by

torsion, has gills in primitive forms, but these are lost in some groups, replaced by secondary structures, or by •

a lung in land snails. There are about 35,000 species. l

The Seaphopoda, also known as the tusk or tooth shells, is an exclusively marine group, members

of which have an elongate, curved, tapered, tubular shell from 2-150 mm in length that is open at both ends. •

The group, which is bilaterally symmetrical, is entirely marine, occurring from shallow to deep water. There

is a radula, and the wider anterior end has numerous, elongate contractile f'flaments called captacula, with

which they capture benthic microorganisms. They can dig in soft substrata by means of a lobed foot. The •

mantle cavity is tubular, and they take water into and expel it from the posterior end, which extends above i

the substratum. There is no gill. There are approximately 300 species.

The Bivalvia are found in marine and freshwater environments. As the name implies, almost all i

species are enclosed in a pair of lateral valves that are hinged dorsally. Some groups are cemented to the

substratum by one valve. In some groups, the animal cannot be enclosed within the paired valves, and in one

group the entire animal is surrounded by a calcareous tube, with the tiny valves embedded on its surface. •

Primitive forms are benthic feeders, using collecting and sorting organs near the mouth called palms. In

most, there are a pair of complex gills called ctenidia, which not only provide respiration but also strain and

sort food particles from the water, which are then processed by much-reduced palps. The posterior end of •

the mantle cavity is modified into incurrent and excurrent siphons in many groups. In some offshore marine

taxa, the ctenidia have become reduced and the mantle cavity modified for capture of prey as small crustaceans.

There is no radula. There are about 8,000 species, i

The Cephalopoda include the squids and octopods, and modem representatives with the single exception

of Nautilus do not have an external shell but rather an internal calcareous or cartilaginous shell. They are

bilaterally symmetrical, and the head-foot of most has 8-10 flexible tentacles with adherent suckers. There is i

a set of beaks in the mouth and a radula. The mantle cavity contains a pair of gills, and in squids a funnel from

this cavity provides propulsion. There are about 600 carnivorous marine species, of which a number of

shallow-water species are commercially important as food. i

General References on the Mollusca I

Boss, Kenneth Jay. 1982. Mollusca. In: Sybil P.Parker, ed., Synopsis and classification of living organisms,

Vol. 1, and pp. 1092-1096, Vol. 2. New York (McGraw-Hill). 1: xviii + 1166 pp., pls. 1-87; 2:1232 H

pp., pls. 88-141. Pp. 946-1166. i

Dance, S. Peter. 1986. A history of shell collecting, 2nd ed. Leiden (Brill). xv + 265 pp.. 32 pls. •

Morton, John Edward. 1967. Molluscs, 4th ed. London (Hutchinson University Library). 244 pp. [repr.,

1968].

i

Turgeon, Donna DeMorganville, Arthur E. Bogan, Eugene Victor Coan, William Keith Emerson, William B

Gober Lyons, William Lloyd Pratt, Clyde E E. Roper, Amelie Scheltema, Fred Gilbert Thompson &

James David Williams. 1988. Common and scientific names of aquatic invertebrates from the United •

States and Canada: mollusks. American Fisheries Society, Special Publication 16: vi + 277 pp., 12 |

pls.

Vaught, Kay Cunningham, ed. by, Robert Tucker Abbott & Kenneth Jay Boss. 1989. A classification of the

living Mollusca. Melbourne, Florida (American Malacologists). xii + 196 pp.

I
!

I 2. CLASSAPLACOPHORA

| by

Am61ie H. Scheltema 1

!

Introduction

I The Aplacophora are a small class of marine MoUusca represented in the literature by fewer than 300

species worldwide. Most inhabit the deep-sea benthos from the edge of the continental shelf to hadal depths

I over 9,000 m, and nearly every deep-sea dredge or box core sample brings new species to light. All Aplacophora

are free-living.

i The class is comprised of two subclasses, the Neomeniomorpha or neomenioids (---ClassSolenogastres, see Salvini-Plawen, 1985) and the Chaetodermomorpha or chaetoderms (=Class Caudofoveata). All

Aplacophora are vermiform and covered by a cuticle in which are embedded innumerable spicules of aragonite.

The animals range in size from 1 mm to over 30 cm, and in shape from nearly spherical to long and extremely

I Their molluscan affinities clear from the of raduta and its coelomic

narrow. presence a supports, pericardial

cavity around a heart with ventricle and usually paired auricles, ladderlike nervous system similar to that in

chitons, and mantle cavity into which empty gametoducts and anus. As in other Motlusca, most of the body

I cavity Fully expressed body-wall circular, two orthogonal,

is hemocoel. musculature consists of outer middle

and inner longitudinal muscle layers. Neomenioids have an additional pair of ventral longitudinal bands,

giving them their "new moon" shape.

I In the creeping subclass Neomeniomorpha there is a ventral, longitudinal, ciliated ridge, or foot,

within a furrow that begins from an anterior pedal pit just posterior to the mouth (Fig. 2.2C). This character

i separates them from the burrowing subclass Chaetodermomorpha in which a foot is lacking. Cephalization is only weakly expressed in neomenioids; indeed, sometimes the anterior end can be determined only from the

posteriorly facing spicules along the foot furrow. Chaetoderms have a cuticular oral shield, often exposed,

and fringing spicules around the posterior mantle cavity. In both groups the mantle cavity is small and posterior;

I in the chaetoderms it houses a pair of ctenidia (Fig. 2.14B). The gut is composed of a mouth, a pharynx with

a radula (sometimes lacking in neomenioids) and salivary glands, a combined (neomenioids) or separate

(chaetoderms) stomach and digestive gland, intestine, and anus.

I The reproductive system, unique among mollusks, has a paired or fused gonad that empties directly

into the pericardial cavity. The gametes pass posteriorly through the pericardium into U-shaped gametoducts

i that emptySensory throughelements the glandular in bothlower subclasses limb int consist o the ofmantle one orcavity. more dorsoterminal sense organs (Fig. 2.12B)

In neomenioids, a vestibule with sensory papillae lies above the mouth, with which it usually shares a common

I opening (Fig. 2.2C). General accounts of the group in English are Heath (1911), Hyman (1967), Salvini-Plawen (1985),

Scheltema (in press), and Scheltema et al. (1994). A systematic account appears in Salvini-Plawen (1978) for

I Neomeniomorpha and in Boss (1982) for the whole class.

!

I _Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543 USA.

! 3
!

Reproduction and Development I

The chaetoderms have a unique, derived ectaquasperm, or externally fertilizing sperm (Buckland- •

Nicks and Chia, I989). Neomeniomorpha, on the other hand, have a primitive introsperm, that is, a fiUform, |

internally fertilizing sperm (Buckland-Nicks and Scheltema, in prep.). External fertilization is thus presumed

for chaetoderms, which are dioecious and have a simple reproductive tract, and internal fertilization for I

neomenioids, which are hermaphroditic and have a more complicated reproductive tract with seminal receptacles, 1

sometimes seminal vesicles, and often copulatory spicules.

Development is lecithotrophic, the larvae called "pericalymma" or "test-cell" larvae. They are similar m

to the larvae of protobranch bivalves, with a ciliated, cellular test within which the juvenile develops. In I

aplacophorans the test is eventually engulfed by the expanding ectodermal layer (Thompson, 1960). A larva

of one species was said to go through a stage with seven bands of spicules, reminiscent of chiton plaques •

(Pruvot, 1890). l

Phylogeny I

The phylogenetic position of the Aplacophorans among the Mollusca is not certain. Their highly I

modified external worm shape and primitive-appearing internal anatomy have been interpreted as indicating I1

that they are basal mollusks, with the chaetoderms the sister taxon to all other extant mollusks (Salvinilira

Plawen, 1985), or that they are progenetic aculiferans, sharing sister status to conchiferan mollusks with the m

Polyplacophora (Schettema, 1993). In the latter case, the aplacophoran worm shape is considered to have II

evolved only once and the Chaetodermomorpha are said to be the more derived of the two subclasses, with

m

loss of the foot, reduction in the nervous system, and a derived digestive system. 1

Habitat and Behavior

!

Insofar as known, aplacophorans are carnivores or emnivores. Neomenioids mostly prey on Cnidaria,

grasping their prey with the radula and sucking out tissue with a muscular pharynx (Scheltema and Jebb, m

1

994). Chaetoderms feed on foraminiferans or organic debris, the radula apparently used for capture. Only in II

the Prochaetodermatidae is the radula known to be used for rasping (Schehema, 1981). Movement is extremely

slow in all Aplacophora. Neomenioids creep on or within sediment on their ciliated, nonmuscular foot, or they 1

wrap around hydroids or octocorals upon which they prey. Chaetoderms, on the other hand, burrow through 1B

the sediment by means of a hydrostatic skeleton.

E

Life histories are unknown except partially for one deep-sea prochaetodermatid species from the •

Western North Atlantic that lives at 2,000 m depth. This species becomes sexually mature within one year i

(Scheltema, 1987).

!

Aplaeophora of the Santa Mada Basin and Santa Barbara Channel

Neomeniomorpha are represented in the Santa Maria Basin and Santa Barbara Channel MMS 1

collections by only 4 species and 29 individuals, but there are 11 species and 116 individuals of

w

Chaetodermomorpha. The family Chaetodermatidae, in particular, is represented by 9 species, with 3 further m

species known from the Southern California Bight but not present in the Santa Maria Basin samples examined II

here. This radiation is the greatest yet discovered for a chaetoderm fauna. II

Excluding unnamed species represented by a single individual, depth distributions can be determined 1

for 11 species as shown in Table 2.1. The divisions are based on the dendrogram figured in Blake (1993). 1

4 I
i

I Table 2.1. Aplacophom of the Santa Maria Basin: Vertical Distribution

I Species Inner Outer Upper

I Shelf Shelf Slope

?Gymnomenia minuta +

I ?Genitoconia mariensis + +

Limifossor fratula +

Chaetoderma argenteum +

Chaetoderma californicum +

I Chaetoderma el nanulum egans + + +

Chaetoderma pacificum +

I Falcidens hartmanae +

longus +

Falcidens macracanthos + +

i Spathoderma caIifornicum +

I Three species can be considered as exclusively continental shelf species, whereas the majority_ 9

species, are upper continental slope species. These vertical distributions parallel those known elsewhere, that

I is, that the Aplacophora are primarily creatures of the continental slope.

Several species occurring in the Santa Maria Basin have also been taken from depths greater than

1,000 m in the basin south of Santa Cruz Island (referred to as LACM under "Material examined"). These

I deep records are apparently due to slumping of the sediments, which animals with them into the basin.

carry

I External and Hard-Part Morphology

Body Shape

I or laterallNye.omeniomorpha Anterior and pomay sterior be rends oundmaoryoval be rounded, in cross-sepointed, ction, theslanted, oval woridthbulbou greates;steith either er edor nd smaoveyntbrally e the

widest. The mouth/vestibule entrance may be open (Fig. 2.2C) or contracted in a specific manner (Fig. 2.3C).

I The body is circular in cross-section in all chaetoderms, and may be of one width throughout (Fig. 2.7A), or, most usual, divided into two or more regions: anteriurn, often retracted; neck, usually separated

from the trunk by an anterior constriction; anterior mink; posterior trunk; and posterium. Anterior and posterior

I trunks may not be separate, or the anterior constriction may be lacking (cf. Figs.2.8A, 2.11A, 2.16A, and 1.20B). The oral shield may be large or small, circular or greater in one dimension than another, and pierced

or cleft by the mouth opening; dorsally, the two lobes of the shield may be large (Fig. 2.9B) or small (Fig.

I 2.10B).

Spicule Attitude and Form

I Attitude of the numerous spicules of the body ranges from more or less upright (Figs. 2.8A; 2.9A,

n, at) to adpressed against the body (Fig. 2.7A). They may lie parallel or at an angle to the anterior-posterior

i body axis (Figs. 2.9A, pt; 2.20 B, C) and may be only slightly or deeply buried in the cuticle. Many neomenioid

! '
!

species have several layers of spicules within a thick cuticle, but none were collected from the Santa Maria i

Basin. Spicules produce a sheen from dull to glossy or opalescent. They may be thinly or densely arranged

along the body. The spicules around the mantle cavity in both neomenioids and chaetoderms have a distinctive •

pattem according to species. i

Spicule morphology, like shell morphology in other mollusks, is of utmost taxonomic importance

in determining species and often genera. Spicules are minute to large, ranging from 25 0rn to more than 500 •

lain in length and from 1 lam to >10 vm in thickness. They are solid, flat or spherical in cross section, I

straight (Fig. 2.10E-G) or bern (Fig. 2.8F) or sinuous (Fig. 2.6D), oval (Fig. 2.2D) to elongate (Fig. 2.7D-F),

and in neomenioids paddle- or hook-shaped or hollow (Fig. 2.4D). Spicules are often sculptured with ridges •

or grooves, and chaetoderm spicules may exhibit a distinct waist (Fig. 2.1B). Spicules from along the l

ventral furrow in neomenioids differ in shape from those on the rest of the body (Fig. 2.2D, E). Spicule

morphology may differ between different regions of the body, particularly in the family Chaetodermatidae •

(Fig. 2.8E, H), and there may be more than one type of spicule present in particular body regions in both |

neomenioids and chaetoderms (Figs. 2.3E,G; 2.13F,L). The pattern formed by variations in spicule thickness

and determination of greatest thickness are taxonomically important and can be determined from isochromes

formed by birefringence colors (Fig. 2.1). I

Radula I As in other mollusks, the morphology of the radula is important for species and often generic or

family determination. The primitive form of the radula in aplacophorans is distichous, that is, two teeth per

row, andall chaetoderms have a distichous radula, albeit highly modified in the Chaetodermatidae. The radula 1

in neomenioids may be distichous, monostichous (one tooth per row), or polystichous (many teeth per row).

Copulatory Spicules i

Many neomenioids have paired single, double, or multiple copulatory spicules formed within deep,

modified pockets of the mantle cavity (Fig. 2.2F). Only exceptionally are they unpaired. They are of great •

taxonomic importance atthe species level and are particularly useful in distinguishing closely related species. I

Collection and Preservation i

Aplacophora are usually collected in samples takenby dredge, box core, or grab from the soft, level- 1

bottom community. The best general fixation for such samples is buffered 10%formalin, with preservation in i

buffered 80% alcohol within 24 hours. The samples axe then sorted after screening through a fine (.027 mm) i

sieve. Staining with Rose Bengal facilitates the sorting process. Living aplacophorans have been collected by

several methods, according to habitat. Chaetoderms, all of which burrow in muds and silts, can be seen with i

the naked eye in grab samples that are washed through a 1- mm-mesh screen as they are collected. However, i

the chaetoderms need to be sufficiently large (about 2 cm) and numerous (1 or more organisms per grab) in

order to make this procedure successful. Density in an area should be determined by previous quantitative 1

sampling. Capture rates for aplacophorans can be about a dozen animals per hour with grabs taken and

screened as rapidly as possible. Smaller chaetoderms and neomenioids can also be retrieved from dredge

collections which are taken back to the laboratory, where they are carefully screened while the sediment is still 1

fresh and the residue examined under a binocular microscope. The process is tedious as usually only a few

animals are captured, but will bring results if collections are made in areas known to have aplacophorans

present. I

!

° I
I

I o¢D

m o ®

i

-_ _ 0 0 _ 0

_m _ _ m m >- >" 0 > m (D >-

10. . . : -

| A I

I

--biade

I

I rid, waLst

;': ...i '!..

I area of greatest .. :.-.:...i ,_i-._?._,_:i

-_ .. ;:::_ _ base

.... ,..i:i_:_ !

!

Figure 2.1. Spicule morphology: A, crystallographer's interference color chart showing birefringence of

i aragonite under cross-polarized light (diagonal line), thickness (ordinate), and colors (abscissa). The highest order of color for a spicule is determined when all light is extinguished except that

passing through the spicule, starting at the black edge of spicule. The greatest thickness is illustrated

i in B by stippling. An isochrome between any two color bands is indicated by a dotted line and

• shows the pattern consequent upon varying thicknesses in the spicule. The base and blade of a

spicule may or may not be set apart by an ill-defined waist. A spicule may be sculptured by a keel,

indicated by a double line, or by ridges, shown with a single line.

!

Interstitial neomenioids, most of which are usually only about 1 mm long, can be retrieved from

I well-aerated, diving, or intertidally shallow-water, with a trowel coarse insediments. areas of swift The tidal sediments currents areduring collected spring either low tide. by anchor The sediments dredge, areby

placed in buckets with several inches of aerated sea water and not disturbed for a day or two. The top few

I centimeters quickly pouredare then throughremoved a f'me toscreen. a container, The residue stronglyis wagitated ashed intowitha apetri quantity dish and of seaexamined water, andunder the asupematant dissecting

microscope.

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!

One tropical neomenioid genus, Epimenia, is so large (10-30 cm) that it can be collected by divers m

in its habitat, hard coral rock in areas of swift currents with alcyonarian corals. Observations have been

made on living Epimenia collected this way (Scheltema and Jebb, 1994). mm

Laboratory Methods

Taxonomic descriptions of Aplacophora have been based with few exceptions on preserved animals, m

and usually primarily from histologic sections. As the species descriptions herein demonstrate, hard parts and

body shape are adequate for species identifications, although the higher classification of neomenioids, with m

their complicated reproductive systems and variety of salivary glands, depends on histologic sections.

Body Characters m

Measurements are made using dividers, measuring wheel, or digitizer on camera-lucida drawings

of entire specimens, or on lines drawn through the axes of a camera-lucida image. A digitizer could also n

directly measure an image, although this method has not been used yet. Dimensions of the different body m

regions should be made for Chaetodermomorpha, and for Neomeniomorpha, relative differences between

m

anterior and posterior widths and between dorsoventral height and lateral width should be noted. Because m

aplacophorans

are minimal for

are

living

conla'actile,

individuals.

and preserved specimens are nearly always contracted, length measurements m

Spicules I

Temporary slides of spicules aremade by placing an individual in adrop of glycerine inadepression

slide and teasing off a few spicules with a needle or, if spicules are particularly resistant to being removed, []

with the end of a dissecting knife. In this manner, spicules can be removed from particular parts of the body.

Permanent slides are made by first rinsing an individual in distilled water and then placing it in a drop of

distilled water on a slide. After the spicules have been teased into the water-drop, they are thoroughly air-dried •

and permanently mounted with a histologic mountant and coverslip. []

Spicules are drawn at as large a scale as possible under a compound microscope with the aid of a

camera lucida and measured with an ocular micrometer. When solid spicules are placed between crossed m

polarizers of a light microscope 2,spicules produce bands of rainbow colors owing to the high birefringence of

aragonite. The bands, or isochromes, are species specific in their topography, depending upon where and to

what extent each spicule is thickened. The interference colors exhibited by a spicule can be compared to a 1

crystaUographer's chart relating birefringence, interference colors, and thickness, upon which is drawn a

diagonal representing the birefringence of aragonite (Fig. 2.1A). By comparing the spicule colors to the

colors on the interference color chart, one can determine the greatest thickness of the spicule. The microscope _

stage or lower polarizer should be rotated until the background extinguishes all light except that passing

through the spicule. The thickest part(s) of the spicule and at least one isochrome are then traced.

Radula m

The entire buccal mass is dissected from an individual by means of a dorsal longitudinal cut and m

removed to a drop of hypochlorite (filtered household bleach) in a depression slide. In very small specimens, 1

the entire anterior end may need to be dissected and placed in the hypochlorite. After the tissue has dissolved,

aa

the hypochlorite is drawn off with a pipette and the radula washed several times by adding and drawing off

I

_Several types of microscopes are equipped with tmlafizing light, including differential interference comrast (Nomarksi)

optics and petrographic microscopes. I

N
!

distilled water. A drop of glycerine is then added to the slide and the radula drawn under a compound

microscope with the aid of a camera lucida. If the radula is very small (cf. Figs. 2.2G, 2.3H), it should be

i placed make ainpermanent glycerine slide, on a flat the slide, radula,covered clearedwith of tissue, a coverslip, is washed and examined in a quantityat 100x of distilled under water; oil immersion. the use ofToa

small Stender dish works well. After a day, the radula is removed to a drop of CMPC-10 (a mountant

i miscible in water) containing a water miscible stain. A micropipettor can be used to pick up very small radulae. The preparation is allowed to harden for a day and then is covered with clear mountant and a cover

slip.

I Copulatory Spicules

The posterior endof aneomenioid is cut free andplaced in hypochlorite. When the tissue dissolves,

I the drawncopulat as described ory spicuabove les canforberadula teasedprepa outrfro ations. m theTosurrounding make a permanent cuticle, slide, washed, the placed spiculesinareglyce washed rine, and in a

quantity of distilled water, and using a micropipettor placed on a slide to dry. They are then covered by a

I histological mountant and a coverslip.

i List of Species

Subclass Neomeniomorpha

I

Family Gymnomeniidae

i ?Gymnomenia minuta Scheltema, new species ?Genitoconia mariensis Scheltema, new species

I Family Dondersiidae

Heathia porosa Heath

?Nematomenia sp. I

Family undetermined

I Neomeniomorpha sp.

Subclass Chaetodermomorpha

I Family Limifossoridae Chaetoderma pacificum (Schwabl)

Limifossor fratula Heath Chaetoderma scabrum Heath

I Falcidens hartmanae (Schwabl)

Family Chaetodermatidae Falcidens longus Scheltema, new species Falcidens macracanthos Scheltema, new

I Ch Chaetoderma argenteum Heath species aetoderma californicum Heath Furcillidens incrassatus (Schwabl)

Chaetoderma elegans Schdtema, new Scheltema, new genus

i species Chaetoderma hancocki (Schwabl) Family Prochaetodermatidae

Chaetoderma marinelIi (Schwabl)

I Chaetoderma nanulum Heath Spathoderma californicum (Schwabl)

,i 9
!

Abbreviations Used in the Figures I

an, anterium m/v, opening of vestibule and mouth m

ap, apophysis n, neck I

at, anterior trunk pos, posterium

c, carina pp, pedal pit

fr, frontal pt, posterior trunk II

lat, lateral tp, triangular plate 1

lp, lateral projection vf, ventral furrow

me, opening of mantle cavity •

1

Key to the Species of Aplacophora in the Santa Maria Basin, I

Santa Barbara Channel, and Southern California Bight

i

1A. Cuticle interruptedby ventral longitudinal furrow .................................... Neomeniomorpha ...... 2 l

lB. Cuticle entire; oral shield present ............................................................... Chaetodermomorpha. 6

I

[Neomeniomorpha species are differentiated by spicule morphology exclusive of spicules lying beside the

foot furrow] I

2A. Spicules of 1 type ............................................................................................................................ 3

2B. Spicules of 2 or more types ............................................................................................................. 4 I

3A. Spicules rimmed ovals .................................................................................. ?Gymnomenia minuta i

3B. Spicules broad, paddle-shaped ............................................................................. ?Nematomenia sp. 1

spicules ....................................................................................... Neomeniomorpha sp. I

4A. With rodlike

Ill

4B. With oval-shaped spicules ............................................................................................................... 5

5A. Some oval-shaped spicules with elongate points ........................................ ?Genitoconia mariensis !

5B. Some spicules elongate, paddle-shaped ................................................................... Heathia porosa i

[Body shape is used m differentiate the first four species of Chaetodermomorpha. The remainder oftSe key

is based on morphology of anterior trunk spicules at the anterior constriction] I

6A. Body short, cylindrical, body regions not delimited ............................................ Limifossorfratula l1

6B. Body regions differentiated ............................................................................................................. 7 1

7A. Posterium long, narrower than rest of body, anterior and posterior trunk not differentiated ......... 8 I

1

7B. Posterior trunk same width or wider than anterior trunk, trunk regions differentiated by attitude of

spicules ............................................................................................................................................ 9

I

10 |
!

8A. Anterior constriction present ........................................................................... Falcidens hartmanae

8B. Neck and anterior trunk not differentiated by constriction, jaws present ..... Spathoderma californicum

I

9A. Neck and/or anterium greatly expanded, posterior trunk broad, >2x width short, narrow anterior

trunk ............................................................................................................. Furcillidens incrassatus

I 9B. Body elongate, width of posterior trunk <2x width of anterior trunk ............................................ 10

I 10A. Some or all spicules deeply curved or sharply bent ...................................................................... 11

10B. Spicules flat or nearly so ............................................................................................................... 14

I 11A. Spicules of 2 dominant types, one type fiat, longer than curved or bent spicules, thickest basaUy .... 12

llB. Spicules predominantly of 1 type .................................................................................................. 13

!

12A. Shorter spicules bent, usually with many ridges, with abfrontal groove, radula cone straight ........

i 12B. Shorter ..................................................................................................................... spicules curved, ridge of keel single, isochromes pinched in below keelChaetoderma on midanterior nanulum spicules

....................................................................................................................... Chaetoderma scabrum

!

13A. Spicules thickened in inverted V, <130 _m long ...................................... Chaetoderma argenteum

i 13B. Spicules large, thick ( 10 pm), up to 400 _un long, base broad, asymmetrical .................................

............................................................................................................... Chaetoderma californicum

I 14A. Spicules widest medially, tapered basally ...................................................................................... 15 B

14B. Spicules widest and more or less flared basally ............................................................................. 16

I 15A. Spicules ridged, thin (5 pm or less), body slender throughout, radula cone curved ...........................

........................................................................................................................ Chaetoderma elegans

I 15B. Spicules thickest (to 8 prn) laterally or medially or both, ridges few or none, posterior trunk broader than anterior trunk, radula cone straight ...................................................... Chaetoderma pacificum

I 16A. Spicules with few or no ridges, sparse, long (>450 Inn), thick (>10 lit-n);posterior end "glandular,"

knoblike, anterior end usually greatly swollen .............................................. Chaetoderma hancocki

I 16B. Spicules with many parallel ridges ................................................................................................ 17

17A. Spicules to 400 pin long, with abfrontal groove, ridged medially, thickest laterally, radula cone straight

I .................................................................................................................... Falcidens macracanthos

17B. Most spicules <250 pm long .......................................................................................................... 18

i 18A. Spicules flat, thickest laterally or medially, base of radula cone bulbous frontally .........................

...................................................................................................................... Chaetoderma marineIli

i 18B. Spicules somewhat curved, thickest laterally and medially in 3 longitudinal bands, radula cone narrow frontally ...................................................................................................... FaIcidens longus

! I 11
!

Descriptions of Species I

Subclass Neomeniomorpha I

Solenogastres Gegenbaur, 1878 [partim]; Salvini-Plawen (1967, 1985).

Diagnosis. Aplacophorans with ventral furrow within which lies a foot fold and with a more or less 1

distinct pedal pit at anterior end of groove.

III

Family Gymnomeniidae I

Wireniidae Salvini-Plawen, 1978. I

U

Type Species: Gymnomenia pellucida Odhner, 1921.

!

Genus Gymnomenia Odhner, 1921

Diagnosis. Small, 5 mm or tess in length, dorsoventrally flattened, tapered posteriorly, becoming ..1

terminally bulbous (Fig. 2.2A); with midgut sacculations visible through thin cuticle; mouth and vestibule

surrounded, or nearly surrounded, by external fold (Fig. 2.2B, C); pedal pit evaginated and heavily ciliated

(Fig. 2.2A, C); posterior end tapered to point in juveniles; spicules small, flat, thin ovals ridged around 1

perimeter (Fig. 2.2D); radula small, mostly within radula sac, teeth with distichous hooks; ventral salivary I

glands opening through numerous ductules; copulatory spicules in paired bundles of a dozen or more.

It

?Gymnomenia minuta Scheltema, new species I

Figure 2.2 I

Material Examined. Santa Maria Basin, Sta. R-3 (1); Sta. R-6 (5, holotype, USNM 860388;

paratype LACM 2745); Sta. R-9 (20, paratype LACM 2746). hi

Description. A small species less than 2 mm long, spicular coat mossy rather than glistening (Fig. _l

2.2A). Opening to vestibule and mouth broad (Fig. 2.2C). Posterior bulbous in lateral view, mantle cavity

opening small, round, with rounded prominences within (Fig. 2.2B). Oval spicules up to 25 _n long and 11 •

0m wide (Fig. 2.2D); spicules beside ventral furrow up to 47 orn long and 14 pm wide (Fig. 2.2E); all |

spicules 1 gm or less thick. Copulatory spicules in bundles of about 12, tips bent, staff either ridged or

grooved, longest about 65 larn (Fig. 2.2F). Radula examined from 1 paratype: about 20 rows, total length 142 ll

[am;teeth with distal hook, medial denticle, and small proximal denticle, length about 35 pm (Fig. 2.2G). I

Biology. In silts and sandy silts with 16% or less clay and up to 34% sand; occurred at same stations

as Limifossorfratula, Chaetoderma nanulum, C. argenteum, Falcidens hartmanae, and an unnamed species []

of Neomeniomorpha.

Remarks. The original description of Gymnomenia considered both radula and spicules to be lacking

(Ohdner, 1921). However, the easily dissolved spicules (they axe lacking on most of the specimens from the 1

Santa Maria Basin) leave telltale lacunae in the cuticle as illustrated by Odhner, and the tiny radula was

apparently destroyed in the sagittal sections upon which the original description was based.

Generic assigmnent is here based on similarity of spicules, body, and radula to numerous specimens 1

of an undescribed but undoubted species of Gymnomenia off west Africa (Scheltema, 1981, figs. 1A, 2M,N, 4). 1

Etymology. From Latin minutus, small, this being a small species for the genus. I

12 I
I

I Distribution. An upper continental slope species so far known only from the Santa Mafia Basin at

409-410 m, but collections still to be closely examined from the Southern California Bight have similar or

perhaps the same species.

Genus Genitoconia Salvini-Plawen, 1967

I Type Species: Genitoconia rosea Salvini-Plawen, 1967.

I and posteriorly; Diagnosis. pedalSmall, pit indistinct; seldom more edgesthanof 5ventral mm infurrow length, evaginated, nearly roundforming in cross-section, a sharp V; rounded cuticle thin, anteriorly easily

torn; spicular coat glossy; spicules thin, somewhat oval-shaped with rounded base and a distal point; midgut

I sacculations in paired bundles lacking; of upradula to 20.small, mostly within radula sac, teeth with distichous hooks; copulatory spicules

| ---

!

i

I

I F

B mc .02 mm

I 1.0 mm

I Figure 2.2. ?viGymnomenia ews, anterior tominuteftat; CS,cheltema, ventral viewnewofspecies paraty:peA,(LAC B, holoM t2y745 pe )(UsShNMowing860388) mouth,/vlaestibul teral ane dopevenntral ing

and pedal pit; D, E, holotype spicules from body (D) and ventral furrow (E); F, 2 copulatory spicules,

I proximal ends eroded, from a bundle of about 12, specimen C; radula tooth, base not seen, from paratype (LACM 2746).

i

i 13
!

?Genitoconia mariensis Scheltema, new species n

Figure 2.3

I

Material Examined. Santa Maria Basin, Sta. PJ-1 (3, holotype USNM 860389; paratype (LACM !

2747); Sta. R-5 (4).

Description. Up to 4.4 mm long and 1.5 mm in diameter, anterior end slightly bulbous, widest at n

midbody (Fig. 2.3A); posterior mantle cavity wall flattened in lateral view (Fig. 2.3B); retracted mouth/

i

vestibule Y-shaped (Fig. 2.3C). Spicules 1-2 pm thick, mostly ovals with short points, up to 52 pan long x

29 prn wide (Fig. 2.3E), but many others with points half spicule length, up to 79 pm long x 34 prn wide n

(Fig. 2.3G); spicules of foot furrow curved on one edge, recurved on other, 45 pm x 16 lam (Fig. 2.3F). Ill

Copulatory spicules numerous, slender, flat, ridged along edges, ridges meeting to form a solid, rounded,

distal point (Fig. 2.3D); length not determined. Radula 100 [amlong, denticles 31 [amlong with distal hook, i

medial denticle, and shorter proximal denticle; edge away from denticles is recurved (Fig. 2.3H). U

Biology. Taken from silt with 16% sand and sand with 40% silt, both with clay content of 12% or I

less. Collected at the same station as Falcidens macracanthos, i

U

Remarks. This species is placed in the genus Genitoconia on the basis of body shape and glossiness,

evaginated ventral furrow, lack of midgut sacculations, spicule morphology, bundles of copulatory spicules, lm

and radula morphology, i

Etymology. The ending -ensis means belonging to, i.e., the Santa Maria Basin.

Distribution. A continental shelf species so far known only from 145-154 m in the Santa Maria i

Basin, but like Gymnomenia, Genitoconia is a widespread genus (unpublished data), and some species of n

Gymnomeniidae have broad distributions.

Family Dondersiidae 1

Diagnosis. With 2 types of solid spicules; radula monostichous (single tooth per row) with 1 or 2 i

pairs of denticles, the medial denticles fused at tips, or radula lacking.

Genus Heathia Thiele, 1913 U

Ichthyomenia Heath, 1911.

Type Species: lchthyomenia porosa Heath, 1911. 1

Ill

I1

,Ill

Heathia porosa (Heath, 1911) l

Figure 2.4

Material Examined. Southern California Bight, off San Diego, 900-976 m,holotype and paratype l

(Albatross Sta. 4400, 4402, CAS 021406, 021407, spicule slide and serial sections).

Description. According to Heath (1911): average length 16 mm, diameter 1.2 mm (Fig. 2.4A); i

posterior drawn into finger, "but in other cases it may become blunt and trumpet-shaped"; with numerous 1

sensory pits ventrolaterally; radula lacking. All spicules thin, about 1 [amthick, of 2 types: short ovals

drawn to point distally, with thickened rim and light striations, up to 20 x 11 ktrn (Fig. 2.4B), and long II

paddles with short, solid, proximal "handle" and longer, rimmed "scoop," up to 81 x 9 [am (Fig. 2.4D). I

Paddles located along foot furrow, lateral to foot-furrow spicules with which they are juxtaposed on the type

slider, and which are elongate ovals up to 47 x 7 [am(Fig. 2.4C). i

14 i
I

I

I

I

I 1.0 mm

g__ _ C _ I

D

I .05 mm

', E

!

! G

i Figure 2.3. ?Genitoconia mariensis Sclheltema, new species: A, holotype (USNM 860389), dorsal view, anterior

to right; the drawing does not do justice to the shining, glossy coat of spicules; B, paratype, posterior

end, lateral view (LACM 2747); C, anterior end of A, vemral view; D, several copulatory spicules

from B, proximal ends to left probably eroded; E, short-pointed spicules; F, spicule from foot furrow;

i G, long-pointed spicule; H, radula teeth from 2 different views.

I

I porosa inRemmuseum arks. collections. Specimens of Gymnomeniidae from off southern California are sometimes labeled Heathia

Distribution. Known only from type material off San Diego.

.!

I

I 15
1

i

1

_.-_-_,'__'.... -" _','-'.!;'_,_ I

......... .._-.-."_. E

_ _ _ _ _ l I l ll__ _

"_" _ _ l _ll_ :'_

_ " l: l_:l l I l I " l_ l_._

 i i!l'l l:

l_ 11 1 _ lll" l_ ]l _l_l_

_ ll _ _ _ : 1 1 _l 1

I

1

Figure 2.4. Ichthyomenia (= Heathia) porosa Heath: A, figure from Heath, 1911, plate 3, fig. 4; B-D, holotype

spicules from body (B), foot-furrow (C), and lateral to foot-furrow (D). 11

?Nematomenia sp.

Figure 2.5 lll

Material Examined. Santa Mafia Basin, Sta. 1 (1). 1

Description. Length 5.3 mm, dorsoventral width 1.4 mm, body narrower than high; anterior and 1

posterior ends slantingly truncated (Fig. 2.5A, B); with dorsal carina. Spicules paddle shaped, paddle thicker

and forming shelf above handle (Fig. 2.5C, D); length to 65 btrn,width to 32 larn,thickness 4 pm or less. 1

Radula, if present, not known. 1

Biology. Collected from sand with some gravel; silt and clay together <25%.

Remarks. The single specimen is in poor condition. Based on spicule morphology of the paddles, 1

even though a second spicule type was not discovered, it belongs to the genus Nematomenia Simroth, 1893, 1

species of which live and feed on hydroids (see Pruvot, 1891, as Dondersia). This individual may have

dropped off a hard-bottom, fouling prey organism and may not be part of the soft-bottom community. 1

Distribution. One locality at 98 m in the Santa Mafia Basin.

Neomeniomorpha sp. l

Figure 2.6

el

Material Examined. Santa Mafia Basin, Sta R-6 (1). 1

Description. A small species 2.8 mm long, 1.4 mm wide dorsoventrally, and very narrow laterally,

between 1.2 and 1.3mm, rounded anteriorly, pointed posteriorly (Fig. 2.6A-C). Pedal pit indistinct. Spicular 1

coat dull. Spicules small, straight or curved or recurved solid rods and paddles, up to 52 grn long (Fig. 2.6D). 1

Specimen not dissected; radula and copulatory spicules, if present, not known.

I
I

I Biology. Found with an individual of Gymnomenia minuta in sandy silt with 34% sand. Limifossor

fratula, Chaetoderma argenteum, and Falcidens hartmanae occur at the same station.

i Distribution. Known only from a single specimen taken from the Santa Maria Basin at 410 m.

i

1 A B

1.0 mm 0 D

I

Figure 2.5. ?Nematomenia sp.: A, B, posterior and anterior ends, respectively,in lateral view showing dorsal

i carina, spicules not indicated; C, D, lateral and frontal views of spicules.

i

I _

I

, /

i D c__

l B .o5mm C me

I

F_re 2.6, Neomeniomorpha sp.: A, entire specimen, anterior to left; B, C, ventral view of anterior and I

posterior ends,respectively; D, spiculesof body.

I
!

Subclas s Chaetodermomorpha Pelseneer, 1906 I

Caudofoveata Boettger, 1956. i

Diagnosis, Aplacophorans with cuticle entire and with an oral shield.

Family Limifossoridae t

Genus Limifossor Heath, 1904 l

Type Species: Limifossor talpoideus Heath, 1904.

Diagnosis. Short, broad, no divisions of body evident; spicules closely adpressed to body and thickly I

overlaid; oral shield divided; radula large, distichous with 20-30 rows, teeth heavily sclerotized, each tooth

with a large lateral denticle and one or more smaller median denticles on a broad base. i

W

Limifossorfratula Heath, 1911

Figure 2.7 I

Limifossorfratula Heath, 1911: 44, 72, pl. 2 fig. 6, pl. 4 fig. 13, pl. 35 figs. 1-5, 10, pl. 36 fig. 8.---Schwabl,

1963, 261-262.---Salvini-Plawen, I992, 318, figs. 2, I2. I

Material Examined. British Columbia, 181 m (1) (IOS).----Off Oregon, 200-600 m (12) (OSU).-- ill.

California, Santa Mafia Basin, Sta.26 (1, USNM); Sta. 106 (1, SBMNH); Sta. R-3 (1) (voucher, USNM); •

Sta. R-6 (1); Sta. R-9 (i).---Southern California Bight, south of Santa Cruz Island, 626-1,830 m (16) (LACM ule

76-252, 76-253, 76-257, 76-272, 76-271,76-269, 76-268, 76-263); off San Diego, 468 m,syntypes (Albatross

Sta. 4369, CAS 021401, 021402, spicule slide and serial sections, and wet specimen, MCZ). I

I

Description. A short, stout species up to 7.4 rnm long x 2.3 mm wide (to 10 mm long, Schwabl,

1963), length/width index 3.2-3.5 (Fig. 2.7A); mantle cavity distinctly set off from trunk by sharply reduced I

width; oral shield not known; dorsoterminal sense organ present, but not evident except in sectioned material. II

Spicules deeply embedded in cuticle over entire body and forming ring around mantle cavity. Spicules long,

aU 10 lmathick, slightly curved towards body, with very short, sharp keel attapered distal end, taper more or l

less abrupt Fig. 2.7D-G); often longitudinally grooved on either side of raised medial section; narrowest from !

dorsoanterior region, up to 440 pm long and 58 om wide (Fig. 2.7D); mid-dorsally and dorsoposteriorly to

over 500 0m long and up to 87 pm wide (Fig. 2.7E, F); shorter ventrally, many <400 pm long, to 87 larnwide _IR

(Fig. 2.7G). Radula with up to 30 rows, lateral denticles up to 135 Inn long, medial denticles single, up to 72 l

0m long, distance between inner edges of denticles at base 41 0rn (Fig. 2.7B, C) to about 53 0m (holotype). u

Biology. Most specimens taken from the Santa Maria Basin were from muddy silts with 66% or IN

more silt and up to 31% clay; one specimen was collected from sandy silt having 34% sand. Limifossor II

fratula occurred at the same stations as Chaetoderma nanulum, C argenteum, Falcidens hartmanae,

Gymnomenia minuta, and an unnamed species of Neomeniomorpha; and in the Southern California Bight at •

the same stations as F.longus, F. hartmanae, C. hancocki, C. marinelli, C. nanulum, C. elegans, C. scabrum,

|

Spathoderma californicum, and a species of Psilodens. Off Oregon, L. fratula is stouter, with a length/

diameter index of 3:0 or less.

Remarks. Species of Limifossor are not easily confused with any other Chaetodermomorpha. I

Limifossor species are best differentiated from each other by body shape, i.e., length:width index, and radula

morphology. Spicules of L.fratu/a are morphologically similar to those of L. talpoideus Heath, found from I
I

I

l /__ <

_N7

_.0 mm

I

0

I 0.05 mm

.i _ ,_ !C

| /\ • t. .... .. "

..,.,

: "i fi: :_I:

.... " : [:.:..1:...: :

I . . : .. :

: : • .

.II D E E F G

I Figure 2.7. Limifossorfratula Heath: A, specimen from Santa Maria Basin (USNM); B, C, radula of A, dorsal

i

(B) and frontal (C) view; D, E, G, spicules of A from dorso-anterior body (D), mid-dorsal trunk (E),

and midventral trunk (G); F, spicule from syntype (CAS). Longitudinal lines here indicate grooves,

i not ridges.

i 19
I

southern Alaska perhaps as far south as off Oregon, but L. taIpoideus is more slender (index up to 6.0) and i

each radula tooth has two medial denticles. L.fratula is the sole member of the genus known south of San

Francisco. !

Distribution. An upper continental slope species from off Oregon to Southern Califomia Bight i

between 200-600 m, except to 1,830 m south of Santa Cruz Island. Schwabl (1963) reported a depth range

in the Southern California Bight of 140-810 m. if

II

Family Chaetodermatidae D

Genus Chaetoderma Lov6n, 1844

Crystallophrisson Miibius, 1875. Ivanov, 1981. I

kll

Type Species: Chaetoderma nitidulum Lov6n, 1844.

Diagnosis. With distinct body regions of neck, anterior trunk, posterior trunk, andposterium. Radula I 

with paired denticles lying outside dome-shaped cuticutar membrane covering buccal mass and with paired i 

lateral projections extending from radula cone to dome-shaped membrane opposite base of denticles (Fig.

2.8J) (Scheltema, 1972; Scheltema et aI., 1991). I

Chaetoderma argenteum Heath, 1911 i_

Ill Figure 2.8

Chaetoderma argentea Heath, 1911: 43, 62-63, pl. 4 Fig. 7, pl. 26 figs. 1-7, pl 36 fig. I, pl.37 fig. 6. 1

Chaetoderma argenteum: Scheltema et al., 1991. Ill

Chaetoderma attenuata Heath, 1911: 43, 55-59, pl. 4 figs. 3, 10, pl. 5 fig. 1, pl. 12 fig. 4, pl. 25 figs. 1-10,

pl. 36 fig. 2, pl. 37 fig. 8.

Chaetoderma montereyensis Heath, 1911: 43, 61-62, pl. 4 figs. 4, 8, 14, 17, pl. 27 figs. 1,2, 4-11, pl. 37 figs.

Chaetoderma 2,3. montereyense: Salvini-Plawen, 1993. !

Chaetoderma sp. Buckland-Nicks and Chia, 1989.

i

Material Examined. Southeast Alaska, Behm Canal, 148-203 m, holotype (Albatross Sta. 4231, g

CAS 021392, spicule slide and serial sections)', Stikine R. delta, Stephens Passage, and Kasaa Bay, 90-362

m (7) (holotype of C. attenuata, Albatross Sta. 4250, CAS 021393, spicule slide and serial sections; and 6 _1_

paratypes, MCZ).--British Columbia, off SW Vancouver Island, 100-200 m (96) (IOS); Observatory Inlet, II

400-600 m, (36) (IOS); Saanich inlet, 90 m (4) (IOS).---off Oregon coast, t50-200 m (11) (OSU).---Califomia,

Monterey Bay, 70-640 m (31) (leetotype of C. montereyensis, Albatross Sta. unknown, CAS 021397, spicule

slide and serial sections; paratypes and presumed syntypes, MCZ).--Santa Maria Basin, Sta. 19 (1, II

SBMNH); Sta. 59 (1, USNM); Sta. 85 (1); Sta. R-3 (11); Sta. R-6 (7) (vouchers, USNM); Sta. R-9 (3).

Description. Greatest length to more than 40 mm; anterior trunk longer and narrower than posterior I

trunk, narrower than or same width as neck, wrinkled when greatly contracted, with dense, furry coat of short, I

upright spicules; posterior trunk up to 2.0 mm in diameter (Fig. 2.8A). Posterior end roundly truncated, with

short, bushy terminal spicules; posterior mantle cavity wall covered with spokelike spicules (Fig. 2.8A, C). i

Oral shield nearly circular, often retracted, up to 1.1 mm wide by 1.0 mm high, with deep, wide dorsal cleft, II

dorsal lobes large (Fig. 2.8B). Anterior constriction deep, dorsoterminal sense organ obvious. All spicules

widest basally, up to more than t0 Hmthick; neck spicules curved, most narrow, thickest medially at flared i

I

20 U
m.

I

I at ,,___

mm _L\_ _k_ Ii 2.0 ___:,,, po,

i C_"

1.0 mm

1 _ 1"0 mmlp

I ( / i

'|

'

i i

!

!

'

!

K

II E G H

I

I Figure 2.8. presumed Chaetoderma argenteum Heath: A, specimen from Santa Maria Basin (USNM); B, oral shield of

syntype of C. montereyensis (MCZ); C, posterium of specimen A; D-H, spicules of

specimen B, from neck (D), anterior trunk at constriction (E, F), posterior region of anterior trunk

i (G), and mid-posterior trunk (H); J, K, radula of specimen A, frontal view (J) and lateral view of

cone (K), frontal to right.

I 21
!

base, <100 iJxnlong, up to 25 Jamwide (Fig. 2.8D); anterior trunk spicules diagnostic, bent and abfrontally I

grooved (Fig. 2.8F), basally flared and up to 40 tam wide, thickest on each side with isochromes often

meeting in an inverted V, length greatest near anterior constriction, up to 130 pm in length (Fig. 2.8E), Ii

decreasing to 90 _arnat the midpoint and to 80 pan next to posterior trunk, spicules nearest posterior trunk |

sharply keeled (Fig. 2.8G); posterior trunk spicules fiat, tapered, sharply keeled, with 1 or more lateral

ridges on each side and numerous free axial striations on base, from 170 pan long anteriorly to 265 larn m

posteriorly, up to 60 grn wide, thickest medially at keel (Fig. 2.8H). Radula cone large, deeply curved II

laterally (Fig. 2.8J, K), 510 _m long, 140 _unwide frontally, and 190 lainwide laterally in largest specimen

examined, tapered distally in lateral view to narrow end; lateral projections narrow, long, up to 250 lam;

denticles 30 to 60 lain long; cuticular dome one-half length of cone. |

Biology. Chaetoderma argenteum was collected from Santa Maria Basin in silty sands with 48%

sand, in silts, and in muddy silts with up to 24% clay. A juvenile came from the Santa Barbara Channel, south !

of the usual range, in a very muddy silt with 30% clay. In British Columbia, it occurs in fine and muddy silts. |

Species found at the same stations as C. argenteum in the Santa Mafia Basin were C. nanulum, Falcidens

macracanthos, F. hartmanae, Limifossor fratula, Gymnomenia minuta, and an unnamed species of I

Neomeniomorpha; off Oregon and British Columbia it was found with Limifossor cf. talpoideus and Falcidens II

longus.

Remarks. Specimens from British Columbia provided materiaI for the first published account of I

spermiogenesis in a chaetoderm aplacophoran (Buckland-Nicks and Chia, 1989). II

The synonymy of C. montereyense (but not C. attenuatum) with C. argenteum has recently been

questioned based on the presence of a smaller pericardial cavity in the type of C. argenteum and in one

paratype ofC. attenuatum, and small differences in the manner in which muscle fibers of the ctenidial retractors II

divide in C. argenteum and C. montereyense (Salvini-Plawen, 1993). Pericardial size can be related to age

(the type of C. argenteum is a juvenile) or, probably, to reproductive state, as eggs must pass from the gonad I

through the pericardium to the outside in spawning individuals. Muscle fibers can split in divergent ways even B

on two sides of an individual. Therefore, the differences given are not considered here to be more than individual,

or at the most population, differences.

!1 Distribution. Primarily an upper continental slope species from off Pt. Conception, California, to

southeast Alaska, between 70-640 m.

!

Chaetoderma californicum Heath, 1911

Figure 2.9 I.

Chaetoderma californica Heath, 1911: 43, 64-66, pl. 4 fig. 6, pl. 31 figs. 1-4, 7, 8, 10, pl. 35 fig. 11, pl. 37

fig. 14. i

Material Examined. California, Santa Mafia Basin, Sta. 56 (1) (voucher, USNM).---Off San Diego,

1,112-1,200 m, holotype (Albatross Sta. 4381, CAS 021394, spicule slide and serial sections). Possibly the E

same species from off the Farallon Islands, 2,623-2,750 m (47).----off Oregon, 800-2,800 m (2). II

Description. A robust species up to 24 mm long (holotype) and 2.3 mm wide at posterior trunk

(Fig. 2.9A); anterior trunk shorter than posterior trunk, narrowest at anterior constriction, slightly wider •

than neck, with densely arranged, large upright spicules; neck with short spicules; anterium short; posterior I

trunk rough, with large spicules; posterium truncated, spicules extending beyond mantle cavity wall, which

has spokelike spicules not easily discernible through heavy encrustations (Fig. 2.9C). Oral shield wider than "l

high, 1.85 x 1.65 mm, with short dorsal cleft, dorsal lobes large (Fig. 2.9B). Anterior constriction covered I/

by anterior trunk spicules; dorsoterminal sense organ indistinct. All spicules with greatest thickness much

greater than I0 lain and very long except on neck; neck spicules narrow, with short keel and broad base, up ili

to 153 _m long and 36 lainwide (Fig. 2.9E); anterior trunk spicules bent (Fig. 2.9G, lateral view), base long, il
I

i

I _II__O' :l_g_ /_) _

I

1.0 mm D

r

i '_

ii

• .::

i'Q'j

F F G G H H J

i.

i Figure 2.9. Chaetoderma A; C, po californicum Heath: A, specimen from Santa Mafia Basin (USNM); B, oral shield of sterium of A; D, radula reconstructed from holotype sections (CAS); E, G, J, spicules of

specimen A, from neck ('El, anterior trunk at constriction (G, lateral view above), and mid-posterior

i trunk (J); F, H, spicules from anterior (F) and posterior (H) trunk of holotype.
!

broad, asymmetrical, distal ends either narrow (Fig. 2.9F) or, in individual from Santa Maria Basin, both I

broad and narrow (Fig. 2.9G), thickest medially, keeled from distal end to midpoint, usually with several

ridges, spicule length from 230 to 400 lamlong, width from 80 pm (Santa Mafia Basin) to 100 pm (holotype); S

posterior trunk spicules keeled from distal end to midpoint, base flat (most spicules of holotype, Fig. 2.9H I

left) or rounded (most spicules in Santa Mafia Basin individual, Fig. 2.9J below), most holotype spicules

symmetrical, with lateral ridges and keel without ridges, most Santa Mafia Basin spicules without lateral n

ridges but with ridged keel, many with asymmetrical base. One radula examined, from holotype in serial II

sections; cone length about 475 btmlong, frontal width about 85 pro, lateral projections about 50 tmatong

(Fig. 2.9D). I

Biology. Taken in the Santa Maria Basin from a well-sorted sediment with 33% sand, 47% silt, and I

19% clay.

Remarks. Chaetoderma californicum is distinguishable from other southern California species by _l_

its large, thick, asymmetrical spicules. The species is probably also present off the Famlton Islands and the I!

Oregon coast; however, there is enough variation in spicule morphology that identification of the more northern

specimens is not yet certain. The variation may due to the calcification process that produces great spicule l1

thickness in combination with irregular shape. II

Distribution. A continental slope species found off southern California between 900-1,200 m;

possibly to 3,000 m off the Farallones Islands and Oregon coast. I

Chaetoderma elegans Scheltema, new species

Fig. 2.10 i

Material Examined. California, Santa Maria Basin, Sta. 21, paratype (USNM 860390).--Southern i

California Bight, south of Santa Cruz Island, 33°45.85'N, 119°39.25%V, 1,808 m, holotype (LACM 2748). II

Description. Long (holotype 31.6 mm), slender, anterior trunk shaggy, up to twice as long as posterior

trunk (Fig. 2.10A). Neck bent at 90 ° angle, narrower than or same diameter as anterior trunk at constriction. II

Anterior trunk up to 1.0 mm in diameter at constriction, wider posteriorly, to 1.4 mm becoming same width n

as opaque posterior trunk. Posterium rounded, bulblike, spicules bushy, dorsoterminal sense organ indistinct

(Fig. 2.10C). Oral shield wider than high, 1.50 x 1.40 mm (paratype), dorsal lobes small, dorsally cleft (Fig. i

2.10B). Spicules flat, thin, 5 _a or less thick, with those of trunk with parallel sides, rounded or straight II

base, sharp narrow keel, and few to several parallel ridges, easily dislodged from preserved specimens (Fig.

2.10F, G). Spicules of neck narrow, arrow- to nearly rod-shaped, thickened symmetrically or asymmetrically, i

up to 86 larnlong x 16 jamwide x 5 punthick (Fig. 2.10D); anterior trunk spicules both at constriction (Fig. 1

2.10E) and midpoint (Fig. 2.10F) with keel medial or offset laterally, up to 225 jamlong x 35 pin wide x 3.5

/am thick, thickened at keel and ridges; mid-posterior trunk spicules up to 205 x 42 x 5 pro, except a few tll

broader, up to 54 pm wide (Fig. 2.10G). Radula small, curved in lateral view, cone 220 pm long, frontal |

width 50 pro, lateral width 85 _un (Fig. 2.10H, J), dome-shaped piece 140 pm long, denticles (broken) >20

pro, lateral projections about 50 prn; cuticle of dome strongly cuticularized in part. !

Biology. Chaetoderma elegans was taken from a sandy silt (21% sand, 75% silt, 4% clay) in the I

Santa Mafia Basin. The species was not found with other aplacophorans in the Santa Mafia Basin, but

occurred at the same station as C. nanulum south of Santa Cruz Island. /

Remarks. The long, slender body and thinness of spicules distinguish C. elegans from C. pacificum, U

which has a broader body, radula without a curve, longer, thicker spicules on the posterior trunk, and often

longer anterior trunk spicules; and from Falcidens longus, which has basally flared, thicker anterior trunk l

spicules and joined radula denticles. II

Etymology. From Latin elegans, elegant, as the species seems elegant in its slenderness.

i

Distribution. Known from a single specimen from the Santa Maria Basin at 49 m and one from the 1

basin south of Santa Cruz Island at 1,808 m.

24 I

!

Chaetoderma hancocki (Schwabl, I963) .i

Figure 2.11

m

Crystallophrisson hancocki Schwabl, 1963: 272-273, figs. 14, 15. I

CrystalIophrisson inflatum Schwabl, 1963: 276-277, figs. 21, 22.

?CrystaUophrisson rectum Schwabl, 1963: 278-279, figs. 25, 26. I

Crystallophrisson riedli Schwabl, 1963: 274, Sta. 2352 only.

Material Examined. Southern California Bight: San Pedro Basin, 504-803 m (14) (ieetotype, 1

LACM 2093; lectotype and paralectotype of Cr. inflatum, LACM 2097 and LACM 2098; LACM 53-158;

l

LACM 77-204, 77-275, 77-203, 77-276, 77-202, 77274).--south of Santa Cruz Island, 833-1,830 m (18) /

(LACM 76-252, 76-253, 76-258, 76-271, 76-270, 76-269). 1

Description. A distinctive long, slender species up to 45 mm long x 2.0 mm wide at posterior trunk,

often greatly swollen anteriorly, knoblike posterior end, spicules large, anterior trunk shaggy with spicules m

sparsely scattered (Fig. 2.11A). Anterior trunk longer than posterior trunk; anterium and neck divided by deep II

constriction; spicules of anterior trunk easily dislodged; posterior wall of mantle cavity extending without

spicules beyond spiculose body wall, ending in a round, glandular-appearing protuberance with dumbbell- j

shaped opening (Fig. 2.11D, E). Oral shield large, width and height nearly equal, up to 1.90 x 1.80 mm, with |

short dorsal cleft and large dorsal lobes (Fig. 2.11B, C). Anterior constriction deep, with dorsoterminal sense

organ obvious, long, extending from outer body walt onto protruded, glandular posterior mantle cavity wall. i

Spicules long, fiat, with little or no sculpturing; type I spicules (Fig. 2.11H, K, N, O) with or without parallel II

ridges on basal half, often with narrow medial keel, thickest medially, up to 8 pm thick, flared basally on neck

and anterior trunk, more than 200 pm long x 60 pat wide on neck, up to 300 x 60 pm on anterior trunk at lm

constriction, >300 x 55-60 pm on mid-anterior and mid-posterior trunk, ridges most numerous on posterior |

trunk; type 2 spicules (Fig. 2.11J, L, M) usually without sculpturing, lateral edges slightly convex, longer and

thicker than type 1 spicules from same region, neck spicules thickest medially and up to 250 x 52 x 10 _xm, aim

trunk spicules thickest laterally, with thickenings joining distally in inverted V, up to >450 x 60 x >10 pro. ]_

Trunk spicules commonly with one lateral edge at base more curved than other (Fig. 2.11 M-O). Radula cone

i

large, curved, up to 520 Ima long, frontal and lateral widths nearly equal, 150 and 165 pro, respectively, m

lateral projections short, teeth small (30 pm), dome extending from one-third to two-fifths cone length (Fig. J

2.11F, G).

Biology. Qualitative descriptions of the sediment in which Chaetoderma hancocki has been found ill

are sticky or oozy muds and clay. The species has been found at the same stations as Chaetoderma nanulum, II

C.scabrum, ?C marinelli, Falcidens hartmanae, F. longus, Limifossor fratula, Spathoderma californicum, and

Psilodens sp. 111

Remarks. Crystallophrisson inflatum Schwabl is synonymized with Chaetoderma hancocki 1

(Schwabl) based on similarity of body morphologies in the two lectotypes and single paralectotype of Cr.

inflatum. Although spicules are now entirely lacking on the lectotype of Chaetoderma hancocki, a few j

remain on the lecto- and pamlectotypes ofCrystallophrisson inflatum and can be compared to spicules from I1

recently collected specimens and Schwabl figures for both (1963, figs. 14, 21). The small radula denticles

were considered to be lacking in the original descriptions of both Chaetoderma hancocki and •

Crystallophrisson inflatum (Schwabl, 1963). l

Distribution. Off southern California on the upper continental slope between 508-1,830 m. The

species has not been found north of Pt. Conception and was not in the Santa Maria Basin collections. !l

I

J
I

I Figure 2.11. Chaetoderma hancocki (Schwabl): A, specimen from San Pedro Basin (LACM 77-203, 77-276),

deep constriction between anterium and neck indicated by arrow; B, C, oral shield of specimen A

I (B) and lectotype (C, LACM 2093); D, E, posterium of lectotype (D) and specimen A (E); F, G, radu|a of specimen from San Pedro Basin (LACM 77-204, 77-275), frontal view (F) and lateral view

of cone (G), frontal to right; H-O, spicules of specimen A (H-L, O) and lectotype ofCr. inflatum (M,

N) from neck (type 1, H, type 2, J), anterior trunk (type 1, K, type 2, L) and posterior trunk (type 1,

i M, type 2, N, O).

i 27
!

Chaetoderma marineUi (Schwabl, 1963) i

Figure 2.12

Crystallophrisson marinelli Schwabl, 1963: 277-278, figs. 23, 24. I

Material Examined. Southern California Bight: off San Diego, 47-64 m (5) (SD Sta. A-2, A-10 I

[voucher, LACM], B-1, B-5).--San Pedro Basin, 29 m leetotype (LACM 2099); 1 specimen from type I

station, not syntype (LACM 53-94); 1 specimen identified by Schwabl as C. pacificum, 50 m (LACM

2102). I1

Description. A large species up to nearly 40 mm x 3.3 mm in posterior trunk diameter (lectotype); I

other specimens 20-30 mm long x 1- to 2 mm posterior trunk width. Neck narrower posteriorly than anteriorly

except when fully contracted as in Figure 2.12A. Anterior trunk shaggy, about same length as posterior trunk, qll

Posterium rounded, somewhat bulbous, with short terminal spicules and, in large lectotype, spiculeless a

collar around mantle cavity; dorsoterminal sense organ obvious (Fig. 2.12B). Oral shield dorsally cleft, nearly

spherical, up to 1.1 mm in width, with large dorsal lobes (Fig.2.12C). Spicules of both anterior and posterior II

trunk with many parallel ridges, posterior trunk spicules usually shorter than those of anterior trunk. Neck II

spicules narrowly or broadly arrowhead-shaped on smaller specimens (Fig. 2.I 2D), nearly rod-shaped on

large lectotype (Fig. 2.12E), asymmetrically thickened except in broad spicules, up to 120 pm long x 23 prn _l

wide x 7 prn thick; anterior trunk spicules flat, keeled, most thickened laterally only, but also medially, or I

both, base striaght to slightly flared, lateral edges often appear thickened in plain transmitted light, up to 260

x 40 x 9 pm (Fig. 2.12F, H); mid-posterior trunk spicules somewhat curved towards body, lateral edges m

straight, thickest at keel and sometimes at adjacent ridge, less than 225 lain long, up to 40 gm wide x 7.5 _un I

thick (Fig. 2.12G, J). Radula cone large, up to 370 pm long, proximally bulbous and curved in lateral view,

width up to 145 pm frontally and 174 pmalaterally, dome-shaped cuticle up to 232 prn long, denticles up to lib

35 prn long (Fig. 2.12K, L). |

Biology. Probably a shallow-water species occurring at <65 m. Found with Falcidens longus at

some stations. Sediment type not known.

I Remarks. Chaetoderma marinelli can be confused with C. pacificum, Falcidens macracanthos, and

E Iongus. The anterior trunk spicules ofC. marinelli are simi/ar to, but shorter than those ofE macracanthos,

and the radulae differ. The species is differentiated from C. pacificum by the many ridges and flared base I

present on anterior trunk spicules, by the shorter mid-posterior trunk spicules, and by the flared proximal end U

of the radula cone; neck spicules in both species are thickened asymmetrically. It differs from F. longus by

radula morphology and by the flat, basally less flared anterior trunk spicules which are predominantly n

laterally thickened. l!

Distribution. A continental shelf species in the Southern California Bight from 30-64 m.

I

t

!

i

t

|

!

Chaetoderma nanulum Heath, 1911 I

Figure 2.13

l/

Chaetoderma nanula Heath, 1911: 66-67, pl. 4 figs. 1, 12, pl. 27 fig. 3, pl. 28 figs. 7, 10-12, pt. 37 fig. 18. I_

Crystallophrisson riedli Schwabl, 1963: 274-276, figs. 19, 20. in

CrystalIophrisson rubrum Schwabl, 1963: 280, figs. 27, 28. II

Crystallophrisson scabrum (Heath): Schwabl, 1963:269 [extant material from AHF Sta. 2418].

Material Examined. California, Santa Maria Basin, Sta. 16 (4) (vouchers, USNM); Sta. 54 (5, I

SBMNH); Sta. 60 (2); Sta. 61 (2); Sta. R-2 (1); Sta. R-3 (7, USNM); Sta. R-7 (l).---Southern California

Bight, Santa Barbara Channel, 337 m (1) (LACM 77-279); south of Santa Cruz Island, 833-1,843 m (24) _l

(LACM 76-252, 76-253 [voucher, LACM], 76-257, 76-258, 76-271, 76-270, 76-269, 76-268, 76-263, 76- ,il

262); San Pedro Basin, 333 m (6) (AHF Sta. 2418, as CrystaUophrisson scabrum in SchwabI, 1963); 558 m,

lectotype and paraleetotype Crystallophrisson riedli (LACM 2105, 2106); 250-504 m (7) (LACM 77-293, Ill

77-203, 77-276, 77-260).---off San Diego, 468 m, holotype (Albatross Sta. 4369, CAS 021398, spicule II

slide and serial sections).

i

Description. A species greatly variable in body and spicule size. One individual from Santa Maria _i

Basin (Sta. R-7) 44 mm long; all others examined 15 mm or less. Anterior trunk shaggy, about equal to or II

shorter than posterior trunk plus posterium, slightly narrower than neck (Fig. 2.13A, B); posterior trunk up to

3.7 mm wide, usually <3 mm; anterior trunk only slightly less wide than posterior trunk. Oral shield wider a

than high, up to 1.65 x 1.40 mm, with short dorsal cleft and small dorsal lobes (Fig. 2.13C). Posterior end 11

truncate, ringed by long spicules; few spicules on posterior mantle-cavity wall (Fig. 2.13D). Anterior constriction

and dorsoterminal sense organ obvious. Spicules thick, those on anterior trunk of 2 distinctive types. Neck _J

spicules long, bent, arrowhead- to rod-shaped, often ridged, usually thickest basally but also medially, or l

both, often asymmetrical, up to 130 lxrn long x 30 larn wide x 10 _tn thick (Fig. 2.13E). Spicules of anterior

trunk of 2 main types: type 1bent outward, flared basally below a waist, thickest basally at broad ridged keel J

over an abfrontal groove, bearing sharp lateral ridges (Fig. 2.13F, J); some with narrow keel (Fig. 2.13H); II

greatest spicule dimensions not correlated with body length except in individuals <4 mm long, largest spicules

ranging from 152-240 _rn long, 50-75 _m wide, and up to 10 parnor more thick (Fig. 2.13 cf. F, G, H); type Ill

2 spicules longer than type 1 spicules, fiat, thickest laterally, or medially, or both, waist scarcely or not I

evident, ridges faint, size variable as for type 1 spicules, ranging from 185-390 _trrtlong, 30-70 lainwide, and

up to 10 prn or more thick (Fig. 2.13K, L). Mid-posterior trunk spicules fiat, with sharp keel and ridge along I1

each side running nearly to base, with shorter ridges between the lateral ridges and edge of spicule, thickest at 41

keel, isochromes symmetrical around keel, up to 300 _trnlong, 60 _tmwide, and 10 tim thick, usually shorter

than type 2 anterior trunk spicules (Fig. 2.13M). Radula cone straight, nearly as wide frontally as laterally, up I1

to 475 _trnlong, 115 _na in frontal width, and 140 _m in lateral width; lateral projections up to 70 pxrnlong; I

denticle length up to 55 lam; cuticular dome extending one-half length of cone or less, slightly to greatly

tanned distally. I/

Biology. Chaetoderma nanulum was collected from a wide range of silty, sandy, and muddy sediments _l

in the Santa Maria Basin, with the sand content ranging from 2% to 59%, the silt fraction from 33% to 85%,

and the clay fraction from 8% to 30%. It was the only aplacophoran species to occur at Sta. R-7 in the oxygen rill

minimum zone (see Blake, 1993: Vol. 1, p. 26). The great variability in morphology and habitat may indicate II

that a species complex is involved here under a single species name. Chaetoderma nanuIum was taken in the

Santa Maria Basin atthe same stations as Chaetoderma pacificum, C. argenteum, Limifossorfratula, Falcidens I1

hartmanae, and Gymnomenia minuta and, in addition to these, in the Southern California Bight at the same |

stations as Spathoderma californicum, Chaetoderma hancocki, C. elegans, C. scabrum, Falcidens Iongus,

and a species of Psilodens. 1
I

i Figure 2.13. individual Chaetodermafromnanulum Santa Barba Heath: ra Basin A, specimen (USNM); from C, oralSanshieldPedroof large Basinindividual (LACM from77-293); SantaB,Barsmall bara

Basin (USNM); D, posterium of specimen A showing dorsoterminal sense organ (stippling); E, neck

I spicule of large individual; F-H, type 1 spicules of anterior trunk from: holotype (F, CAS), specimen A (G), specimen from south of Santa Cruz Island (H), and 44-mm individual (Sta. R-7, USNM)(J);

K, L, type 2 spicules of anterior trunk from holotype (K) and 44-mm individual(L); M, posterior

trunk spicule from holotype; N, O, frontal and lateral views of radula of specimen from south of

i Santa Cruz Island (LACM 76-553).

i 31
!

Remarks. Only Chaetoderma scabrum has similar anterior trunk spicules; however, C. nanulum I

type 1 spicules have a heavily ridged keel, and type 2 spicules are blunter distally and thickest laterally and

medially. Posterior trunk spicules in C. nanulum are narrower than those in C.scabrum and have a sharp keel !1

to the base and lateral ridges. II

Three specimens labeled CrystaUophrisson riedli Schwabl are extant, all with few or no spicules.

One, from AHF Sta. 2352, is cf. Chaetoderma hancocki (Schwabl). Of the two specimens from Sta. 2150, _l[

one was chosen as the lectotype from its similarity in body form and measurements to Schwabl's illustration II

(1963, Fig. 30)(LACM no. 2105). The second specimen, distorted and without spicules, may or may not be

the same species (LACM no. 2106). Synonymy of Cr. riedli with C. nanulum Heath is based on body ]J

measurements, shape of the mantle cavity wall, and morphology of spicules from the posterior end. II

Crystallophrissom rubrum Schwabl was described from a single specimen apparently no longer

extant. It was found at Sta. 2150 with Cr.riedli, from which it was differentiated on the basis of its purple i

color, but there is great similarity between these two species in the illustrations of the spicules (Schwabt, U

1963, Figs. 19, 27) and of the animals (Figs. 20, 28), as well as in the written descriptions. Cr. rubrum is

therefore here considered a probable synonym of C. nanulum, its purple color due to diet and not a species I

character. II

Distribution. An outer continental shelf-upper continental slope species of the Santa Mafia Basin

and Southern California Bight between about 160-650 m, except to 1,843 m in the deep basin south of Santa

Cruz Island. I

Chaetodermapacificum (Sehwabl, 1963) i

Fig. 2.14

Crystallophrisson nitidulum var. pacificum Schwabl, 1963: 273-274, figs. 16-18. I

Material Examined. California, Santa Mafia Basin, Sta. 60 (1) (USNM).---Southern California i

Bight, south of Santa Cruz Island, 1,464 m (1) (LACM); San Pedro Basin, 22-279 m, lectotype (LACM 1

2100) and paraleetotypes (LACM 2101 [probable, spicules lacking], 2103, 2104); off San Diego, 62-80 m

(2) (SD Sta. A-4, A-15).

Description. A large species up to 30 mm long x 2.5 mm in posterior trunk diameter (Fig. 2.14A). 1

Neck more slender posteriorly than anteriorly when not fully contracted. Anterior trunk shaggy, spicules often

mlw

dislodged in preserved specimens, same length as or only 2 to 3 mm longer than posterior trunk. Posterium /

somewhat bulbous, with short terminal spicules and spiculeless collar around mantle cavity opening; R

dorsoterminal sense organ obvious (Fig. 2.14B). Oral shield dorsally cleft, with large dorsal lobes, wider than

high, up to 1.0 x 1.7 mm (Fig 2.14C). Spicules long, fiat, only those of posterior trunk with many parallel

ridges (Fig. 2.14F-H). Neck spicules slightly arrowhead-to rod-shaped, up to 118 gm long but usually <100 R

lam,base narrow, up to 18 gm wide, and up to 7.5 gm thick, usually thickened asymmetrically (Fig. 2.14F);

anterior trunk spicules with parallel sides and slightly tapered base, up to 300 gm long x 35 grn wide x 8 gm I

thick, most >200 gm long, keeled but with few or no ridges, thickest laterally, or medially, or both, shorter .I

than ridged mid-posterior trunk spicules (Fig. 2.14G); 2 types of spicules predominant on mid-posterior 'IB

trunk, one similar to anterior trunk spicules, the other longer, ridged, and broad, up to 400 x 55 x 10 __rn,

many >300 gm long by 7.5-8 Inn thick (Fig. 2.14H). Radula large, cone straight in lateral view, up to 425 gm

long, 90 larn wide frontally, and 150 _tmwide lateraUy; denticles to 40 grn long; cuticular dome to 275 tam m

long; lateral projections broad, to about 60 orn long (Fig. 2.14D. E).

Biology. Chaetoderma pacificum was collected with C. nanulum in the Santa Mafia Basin from a I

sandy silt with 33% sand and 15% clay. In the Southern California Bight the species was found with Limifossor W

fratuIa and Falcidens Iongus. I
i1

I

I c

3.0 mm ":;} _.;. '

II _ _°

pt ,/ _.., _. :/'1

| _ -_ _-}_{G.

A 1.0 mm

i

| ° iiii_ 't

_ "

' !

!

! " 1

I D,,_..JEi. "_:!

0.1 mm

0.1 mm

I Figure 2.14. Chaetoderma pacificum (Schwabl): A-H, specimen from Santa Maria Basin (USNM). A, entire specimen; B, posterium, mantle cavity open and ctenidia extended, dorsoterminal sense organ black;

C, oral shield; D, frontal view of radula; E, lateral view of radula cone, frontal to left, base broken; FH, spicules from neck (F), anterior trunk at constriction (G), and mid-posterior trunk (H).

| 33
!

Remarks. Chaetodermapacificum is differentiated from C. marinelli by (1) length of mid-posterior I

trunk spicules, which are more than 250 Fanin C.pacificum; (2) relative lengths of lrunk spicules: those from

the anterior constriction are shorter than those from the mid-posterior trunk in C. pacificum and longer in C. !1

marinelli; and (3) in C. marinelli, anterior trunk spicules bear many parallel ridges and are basally flared, II

whereas in C. pacificum, they have few to no ridges and are slightly tapered basally. Anterior trunk spicules

are similar in shape to, but thicker than, those in C. elegans; greater body width and uncurved radula cone of II

C. pacificum readily distinguish the two species. II

Distribution. A continental shelf species taken from off San Diego north to the Santa Mafia Basin

from 22 to 280 m, except to 1,464 m south of Santa Cruz Island. I

u

Chaetoderraa scabrum Heath, 1911

Figure 2.15 I

Chaetodermascabra Heath, 1911: 44, 63-64; pl. 4figs. 2, 16, pl. 29 figs. 6, 7, 9-11, pl. 30 figs. 1, 3, pl. 37

fig. 19. I

Material Examined. Central California, off Monterey Bay, 1,568 m, holotype (Albatross Sta.

4538, CAS 021400, spicule slide and serial sections).--Southern California Bight, south of Santa Cruz I

Island, 833 m (1) (LACM 76-271); 1,101 m (1) (LACM 76-270); northwest of San Nicolas Island, depth W

unknown (2) (LACM 77-238); San Pedro Basin, 504 m (1) (LACM 77-203, 77-276).

Description. Similar in appearance to C. nanulum. Greatest length 18 mm; anterior trunk shaggy, i

shorter than posterior trunk, narrower than neck and posterior trunk; diameter of posterior tnmk up to 2.7 mm ti

(Fig. 2.15A). Expanded oral shield nearly circular, 1.80 x 1.90 mm, pierced by mouth opening (Fig. 2.15B).

Posterior end rounded, bushy (Fig. 2.15C). Anterior constriction obvious, dorsoterminal sense organ narrow t

but distinct. Neck spicules bent, with waist, thickest usually both basally and medially, <200 _rt long, up to

60 larnwide, and 10 bumor more thick (Fig. 2.15D). Anterior trunk spicules near anterior constriction of two

types: type 1 narrowly keeled, curved, basalty flared, thickest medially and laterally at base, up to 300 pin

long x 90 _rn wide x 10 pm or more thick (Fig. 2.15E); type 2 spicules long, without sharp keel, flared II

basally, thickest either medially, or basally, or both, up to 420 x 90 x >10 bun (Fig. 2.15F). Spicules of midanterior trunk with isochromes pinching inwards between thickened base and blade, a character diagnostic

for this species; sides convex, with keel and short lateral ridges, up to 290 x 70 x 10 pm (Fig. 2.15G, H), II

spicules of mid-posterior trunk to 420 x 80 x 10 pm, isochromes around keel bulged outwards. Radula with

curved cone 425 lam long, widths 100 iprn frontally, 150 _na laterally, denticles 30 _a_a,lateral projections

100 pro; dome heavily tanned distally, extending nearly one-half length of cone (Fig. 2.15K, L). I

Biology. Sediment type unknown. Found atthe same stations as Chaetoderma hancocki, C. nanulum,

and Falcidens hartrnanae. _i

N Remarks. Chaetoderma scabrum resembles C. nanulum in body dimensions and similarity of type 1

spicules near the anterior constriction. However, in C. scabrum, type 1 spicules lack the broad, ridged keel

found in C. nanulum. Spicules from the mid-anterior and posterior trunks and type 2 spicules at the anterior

constriction have little resemblance between the two species. C. scabrum is further differentiated by a pierced, ,Ira

circular oral shield, bushy posterior end, and curved radula cone. Five of the specimens identified by Schwabl dh

(1963) as C. scabrum are extant (LACM 53-76); they belong to C. nanulum.

,I

Distribution. An Upper Slope species from off southern California between Monterey Bay and San

Pedro Basin between 504-1,568 m; none occurred in the samples from the Santa Mafia Basin. I

!
I

,,, ,/,, C_-,...>.."-/ ---. i._.___.__

n .....:_, ".,;_L-"._ ,':---" ::, _>'--f_ --_ -"-_--

-"'_....'"":,,!_,," _-_-__

.. : ,,£X,L _,,g_',

A

/'_ 1.0 mm

!

I

I

. 0.1 mm

!

,i ., K 0.2.mmL

I E F G H J

Figure 2.15. Chaetoderma scabnon Heath: A, individual northwest of San Nicolas Island (LACM 77-238); B,

I oral shield, individual from San Pedro Basin; C, posterium of A; D-J, spicules from neck (D), anterior trunk near constriction type 1 (E) and type 2 (F), mid-anterior trunk (G, H), and mid-posterior trunk

(J), all from individual A except spicule G from holotype; K, L, frontal and lateral views of radula of

I individual A, front of radula cone to right in L.
!

Genus Falcidens Salvini-Plawen, 1968 i

Chaetoderma. Ivanov, 1981 (Not Lovtn, 1844).

Type Species: Falcidens crossotus Salvini-Plawen, 1968. 1

Diagnosis. With characters of the family. Radula with paired sickle-like denticles on a cuticular

spring attached to the radular cone and with a triangular back plate (Fig. 2.16C, D); cuticle of buccal mass i

paired lateral membranes (Scheltema, 1972). t

Falcidens hartmanae (Schwabl, 1961) l

U

Fig. 2.16

Crystallophrisson hartmani Schwabl, 196t : 258- 277, figs. 1- 10; 1963, 269-271, figs. 11, 12. I

Material Examined. California, Santa Mafia Basin and Santa Barbara Channel, Sta. 63 (2) (vouchers, n

USNM); Sta. 92 (3, SBMNH); Sta. R-3 (1); Sta. R-6 (1); Sta. R-9 (2, USNM).--Southem California Bight, 1

South of Santa Cruz Island, 1,101-1,843 m (11) (LACM 76-252, 76-253, 76-270, 76-268, 76-262); San

Pedro Basin, 558 m, paralectotype (LACM 2095); 324 m, lectotype (LACM 2094); San Diego Trough, /

1,166-1,241 m, 32°25'-27'N, 117°28'W (11) (SIO, Rokop Sta. R-17, R-36, R-47). I! _

Description. A distinctive species up to 11 mm long with broad trunk up to nearly 4 mm wide and

narrow, tail-like posterium up to nearly 6 mm long (Fig. 2.16A), often heavily encrusted posteriorly with Ill

yellow-brown substance. Anterium usually evident, often large and balloon-like. Neck short, set off from 11

combined anterior and posterior trunk by distinct, though shallow, anterior constriction. Neck and posterium

spicules extending out from body; trunk spicules flat-lying, parallel to body axis. Single row of long spicules Jail

surrounding mantle cavity; posterior mantle cavity wall fiat. Oral shield surrounding mouth opening, lobes l

scarcely evident (Fig. 2.16B). Spicules of anterium short, broad, blunt, lacking ornamentation (Fig. 2.16F).

Neck spicules long, broad, bluntly rounded to somewhat pointed distally, base short, fiat or slightly indented Hi

proximally; some with slight waist; thickened and often ridged distally in inverted V; up to 145 [amlong, 60 II

_m wide,and 7 pamthick in ridges (Fig. 2.16G). Trunk spicules narrower and thinner than neck spicules,

bluntly rounded distally, curved towards body, with single keel or double ridges, up to 170 _rn long, 38 [am tll

wide, and 6 _n thick in ridges (Fig. 2.16H). Spicules of posterium similar to those of trunk, but thinner, up to |

4 pm, and with single sharp keel and a sharp ridge along edges. Radular cone straight, up to 360 larn long,

frontal width to 60 pro, lateral width more than twice frontal width, up to 135 Wn (Fig. 2.16E); lateral lira

membranes up to 200 btrnlong; denticles up to 40 _trn long (Fig. 2.16C,D,E); triangular plate with 2 little I

denticles and a pair of apophyses (Fig. 2.16D).

Biology. Falcidens hartmanae has been collected in silts with up to 34% sand or up to 21% clay. It Jim

has been taken at the same stations in the Santa Mafia Basin as Chaetoderma argenteum, C. nanufum, II

Limifossor fratula, Gymnomenia minuta, and an unnamed species of Neomeniomorpha. In the Southern

California Bight it has also been collected with C. pacificum, C. hancocki, and Falcidens longus. I

Remarks. This species is distinctive. In Schwabl's (1963) description, the spicules labeled "b" in II

Figure 11 are from the trunk, and those labeled "d" axe a mixture from the neck and posterium. The greatest

length given, 18 mm, may be of a distorted specimen with the posterium stretched, am

Dist II ribution. Southern California on the upper continental slope from about 300-1,200 m, except

to 1,843 m south of Santa Cruz Island. A similar species with a smaller radula and larger spicules occurs at

1,200 m and deeper off the Farallon Islands and at shallower depths off the Oregon coast. I

I
!

I

t _ 7'_i -,,.,...--___

!

/ ,

i ..i

i .__..,. ,!

_H- J--

I G <. _'x

0.1ram

i 0.1 mm

t. G H

I Figure 2.16. Falcidens hartmanae: A, specimen from Santa Maria Basin (USNM); B, oral shield of specimen A;

C, D, E, radula of specimens from, respectively, Southern California Bight, San Diego Trough, and

Santa Barbara Basin (USNM) (denticles and triangular plate broken); F-H, spicules from anterium

(F), neck (G), trunk (H), and postefium (J); F, G upper, H upper, J from specimen A; G lower left

I from San Diego Trough; G, H, lower fight, from Southern California Bight. Arrow: scale for spicules.

i 37
!

Falcidens longus Scheltema, new species I

Figure 2.17

t

Material Examined. California, Santa Maria Basin, Sta. R-4 (5) (holotype, USNM 860391; I

paratype LACM 2749); Sta. R-1 (8); Sta. R-8 (22).--Southern California Bight, south of Santa Cruz Island,

1,165-1,812 m (12) (LACM 76-253, 76-269, 246, 76-264, 76-263); south of San Miguel Island, 249 m (2) ll

(LACM 77-282); San Pedro Bay, 32 m (2) (LACM77-273); offSan Diego, 47-81 m (36) (SD Sta. A-2, A- tl

3, A-4, A-5, A-8, A-9, A-10, A-11, A-13, A-14, B-l, B-3, B-5).---Oregon, off Newport, 100-200 m (11)

(OSU).--British Columbia, off Bamfield, Vancouver Island, 106-175 m (82). II_

D NI escription. Elongate, slender to somewhat robust, up to 28 mm long (holotype 15.5 mm) (Fig.

2.17A). Neck sometimes swollen with 2 obvious constrictions; anterium often extended (Fig. 2.17C). Anterior

trunk shaggy with thick-set spicules, same width as neck at anterior constriction, longer than posterior trunk

in specimens >15 mm long, width to 1.3 mm, only somewhat narrower than posterior trunk, up to 1.6 mm. 41

Posterior trunk translucent to opaque. Dorsoterminal sense organ distinct (Fig. 2.17D). Contracted posterior

mantle cavity wall flat to rounded, covered by spoke-like spicules (Fig. 2.17E). Oral shield small, usually

wider than high, up to 1.68 x 1.58 mm, indistinctly dorsally cleft, dorsal lobes small, close to each other (Fig. II

2.17B). Spicules symmetrical, keeled, all but neck spicules with many sharp parallel ridges, fiat except at

anterior constriction where trunk spicules curve slightly outward; narrowly or broadly arrowhead-shaped on IN

neck, up to 146 pna long, base 14-50 pro, up to 8 parnthick (Fig. 2.17F); most anterior trunk spicules at IW

constriction less than 200 [amlong, but up to 215 #Jm,flared at base or with straight sides, sharply keeled to

base, thickest at keel and lateral ridges in three longitudinal bands up to 7.5 pro, or thickest laterally (Fig. I

2.17G); spicules between anterior and posterior trunk thinner, with ridges and keel 3.5 pm thick and up to 200 11

pm long (Fig. 2.17H); posterior trunk spicules up to 215 pm long and 50 _rn wide, keeled and ridged, thickest

medially, 5 pm or less (Fig. 2.17J). Radula cone length up to 300 pro, wider laterally than frontally, curved in I_

lateral view, denticles 40-45 tam,spring between denticles not cuticularized, triangular plate often lacking U

(Fig. 2.17 K,L).

Biology. Falcidens longus was collected from sediments ranging from f'me sand to muddy silt with I

up to 20% clay in both the Santa Maria Basin and Southern California Bight. It occurred at the same stations IN

as Falcidens macracanthos north of Pt. Conception, and with Chaetoderma nanulum, C. hancocki, C.

pacificum, C. marinelli, Falcidens hartmanae, Limifossor fratula, Spathoderma californicum, and a species I_

of Psilodens in the Southern California Bight. Falcidens longus is one of the more common chaetoderm g

species, and box cores often contain small juveniles.

Etymology. From the Latin for "long," indicating a long, slender species. I

_lm

Remarks. Unusual for a species of Falcidens, but similar to F. macracanthos, the spring joining

the radular denticles of F. longus lacks tanning, and the triangular plate, which is very thin, is often missing mlR

in large specimens. FaIcidens longus can be differentiated from Chaetoderma species by radula morphology l_

and externally from F. macracanthos by its shorter, thinner spicules and by the predominance of triply

w

thickened spicules of the anterior trunk; from C. pacificum by more numerous parallel ridges and flared i

base on anterior trunk spicules and shorter posterior trunk spicules; and from C. elegans by a more robust 1

shape and thicker anterior trunk spicules which are flared basally and bear more ridges. Easily confused

with C.marinelIi (q.v. for differences between the two species).

Distribution. A continental shelf species from off Vancouver Island, British Columbia, to the IN

Southern California Bight between 32-250 m, except to 1,812 m in the deep basin south of Santa Cruz

Island. '1

I
i Figure 2.17. Falcidens longus Scheltema, new species: A, holotype (USNM 860391); B, oral shield of specimen

A; C, neck region of specimen A; D, E, posterium of specimen A; F-J, spicules from neck (F),

anterior trunk at constriction (G), mid-anterior trunk(H), and mid-posterior trunk (J), F right, G left

from paratype, rest of spicules from holotype; K, frontal view andL, lateral view ofradula (paratype,

I LACM 2749).

I 39
!

Falcidens macracanthos Scheltema, new species I

Fig. 2.18 II

Material Examined. California, Santa Barbara Channel, Sta. 85, paratype (LACM 2752); Sta. R- _l

4, paratype (LACM 2751); Sta. PJ-1, paratype (LACM 2750); Sta. PJ-17, holotype (USNM 860392).--

San Pedro Basin, depth 82 m (1) (LACM 53-132). i

Description. A short, thickset species distinguished by long spicules inregion of obvious constriction

between smooth neck and shaggy anterior mank and by relatively thick body (Fig. 2.18A). Largest of 4

known individuals 14.0 mm long; holotype 9.9 mm long. Anterior trunk widest at constriction, up to 1.2 I[

mm, narrowing slightly to 1.9 mm posteriorly; posterior trunk somewhat longer than anterior trunk and 11

wider, up to 1.4 mm in diameter, and translucent. Sides of posterium straight, posterior wall of contracted

mantle cavity flat, with spoke-like arrangement of spicules (Fig. 2.18A, B). Dorsoterminal sense organ I

obvious. Oral shield with large lobes, somewhat higher than wide in holotype, 1.40 mm wide x 1.45 mm

high (Fig. 2.18C). Spicules from neck and anterior trunk long and thick. Neck spicules flat, with no or faint

ridges, arrow-shaped, up to 170 Ima long x 38 gm wide x 8 grn thick, thickest basally and either laterally or t

medially (Fig. 2.18E); anterior trunk spicules thickset, flat, held erect, with several medial ridges but not I!l

keeled, grooved abfrontally, thickest either laterally or laterally and medially, base flat and slightly flared,

up to 400 x 52 x >10 grn (Fig. 2.18F), shorter in small specimens (Fig. 2.18H); mid-posterior trunk spicules _l

thinner, up to 7 grn, and shorter, less than 300 lain, with many parallel ridges, thickest medially, base either il

rounded (Fig. 2.18D) or straight. Radula small, cone length up to 223 _xrn,lateral width up to 100 [am,wider

than frontal width, up to 72 gm, not curved in lateral view, denticles up to 50 gm, spring between denticles

not cuticularized, triangular plate present or lacking (Fig. 2.18 G, J, K). II

Biology. Falcidens macracanthos has been collected from sandy silts with up to 16% sand, and J_

from silty sands with up to 72% sand; clay particles were 12% or less. It occurred at the same stations as l[

Chaetoderma argenteum, Falcidens longus, and ?Genitoconia mariensis in the Santa Maria Basin and with Ill

C. pacificum in the San Pedro Basin.

Remarks. The spicules and body shape are similar to Chaetoderma marineIli, but most anterior !

trunk spicules at the constriction are much longer, 350-400 pro, whereas in C. marinelli they are up to 300

pm long and have more parallel ridges. The radula morphology also distinguishes the two species. Like E all

longus, the hinge between the denticles in F.macracanthos is not tanned, and the triangular plate, present in II

the small specimen examined, was lacking in the large specimen.

w

Etymology. From the Greek makros, meaning large, and akantha, a spine. I

Distribution. A continental shelf species known from the Santa Maria and San Pedro Basins between II

82-145 m.

m

FurciUidens Scheltema, new genus I

Type Species: Crystallophrisson incrassatum Schwabl, 1963.

II

Diagnosis. Denticles lacking, the chitinous dome strengthened by a forked distal process of the tl_

cone (Fig. 2.19C).

Remarks. The radula is unique among all known species and genera of Chaetodermomorpha. The !m

forked distal process may be homologous with the lateral processes found in the genus Chaetoderma.

Etymology. From Lalinfurcilla, little fork, and dens, tooth; masculine. I

I

o !
i

I

I n . ,,,,.,,,,4 _._f-Jp<_--_.._.'_..."_. , ,_._..,_

i

I 1.0

mm

0

(-

0.5 mm _ tp t

' '!fl "

I cs ° !

i :i!I

' .j

o _ I \

I

i li! !.!.._... ....

E

I F J O_mm K

I Figure 2.18. Falcidens macracanthos Seheltema, new species: A, holotype (USNM 860392; B, C, posterior

mantle cavity wall and oral shield, respectively, of specimen A; D-F, spicules of paratype no. 1

i (LACM 2750) from neck (E), anterior trunk (F), and mid-posterior trunk (D), spicule F at right same

as spicule to left, greatly reduced, showing pattern of thickening; G, abfrontal view of radula of

small specimen 5.4 mm long (paratype no. 3, LACM 2752) showing triangular ptate; H, spicule of

same specimen as G; J, K, frontal and lateral views of radula of paratype no. 2 (LACM 2751)

i (drawn at smaller scale than G).

I 41
!

FurciUidens incrassatus (Schwabl, 1963), new combination 1

I

Figure 2.19

CrystalIophrisson incrassatum Schwabl, 1963: 267, fig. 8. l

Material Examined. SantaBarbaraChannel, Sta. 91 (1) (USNM); Sta. 99 (2) (USNM); 504 m (3)

(LACM 77-219); 549 m, leetotype (LACM 2096).

III Description. A distinctive species up to nearly 18 mm long, with a greatly expanded neck and

anterium, short, narrow anterior trunk, and broad posterior trunk up to nearly 4 mm in diameter and more

than twice length of anterior trunk (Fig. 2.19A). Neck and anterium separated by strong sphincter in front of l[

which lie the radula and salivary glands; either neck or anterium or both may be expanded. Posterium set off II

from posterior trunk by distinct ridge, cone-shaped when contracted and covered by long spicules.

Dorsoterminal sense organ distinct, entirely within posterium. Oral shield relatively small with large dorsal 1

lobes, usually not expanded, perhaps pierced by mouth opening, nearly round, 1.6 mm wide by 1.5 mm high il

(Fig. 2.19B). Spicules long, narrow, thick, without ridges or sharp keel, anterior and posterior spicules

similar. Neck spicules somewhat arrowhead- to rod-shaped, curved, usually narrowest at base, thickened t

asymmetrically, up to 190 tmalong x 18 larn wide x >10 pm thick (Fig. 2.19E, F); anterior trunk spicules II

indented distally just before tip, and often also indented one or more times along length, thickest distally or

distally and basally, basally curved, length mostly between 300 and 425 _rn long, but up to 550 lam, about I

30-40 larn wide, and 10 _n or more thick (Fig. 2.19G, H); mid-posterior trunk spicules with few or no II

indentations, sometimes with basal keel, many thickened asymmetrically, 400 pm or less long, base to 40

_m wide, and 7.5 to >10 _m thick (Fig. 2.19J). Radula large, total length 850 tam,cone length to fork 500

_n, narrow frontally, 110 _a, and broad laterally, 340 [am;cone weakly and unevenly sclerotized, surrounded Ill

by cuticle not scterotized; cuticle of dome in 2 parts, each surrounding a process of cone above fork and

sclerotized laterally, 400 _tn long (Fig. 2.19C,D). I[_

Ill Biology. Individuals came from soft muddy silts with less than 5% sand and up to 35% clay. The

unique body shape and radula morphology of Furcillidens incrassatus indicate an unusual environment for

an aplacophoran, and no other aplacophoran species was found with it. B

Remarks. No other species is likely to be confused with E incrassatus.

Distribution. An upper continental slope species known only from the Santa Barbara Channel II

between 504-549 m. II

Family Prochaetodermatidae I

Diagnosis. Small Chaetodermomorpha usually <5 mm long with 3 body regions: anterium (often I!

retracted), broad trunk, and narrow, tail-like posterium; without dorsoterminal sense organ; with unique pair I

of large jaws, usually discernible through cuticle (Fig. 2.20A); radula small with about 12 rows of distichous,

serrated teeth, a central plate, and a lateral extension of the radular membrane beside each tooth (Scheltema, II

1981); oral shield divided; spicule morphology similar throughout body, increasing in length posteriorly, I

ventral spicules shorter than dorsal spicules.

Genus Spathoderma Scheltema, 1985 I

Prochaetoderma (partita). Salvini-Plawen, 1992.

I

Type Species: Spathoderma clenchi Scheltema, 1985.

Diagnosis. Spicules spatulate, base flat and relatively long, blade narrow and either curved outward

from body, or twisted in relation to base, or both. I

42 I
I Figure 2.19. Furcillidens incrassatus (Schwabl): A, from LACM 77-219; B, oral shield,

specimen specimen

(SMB Ph. I Sta. 99 USNM); C, D, radula, frontal and lateral views, respectively, sclerotized portions

stippled (SMB Ph. I Sta. 91, USNM); E, F, neck spicules; G, H, anterior trunk spicules; J, posterior

i trunk spicule; D, F, H, J, (SMB Sta. 91); E, G, iectotype (LACM).

I

Jl I 43
!

Spathoderma cah'fornicum (Schwabl, 1963) I

Figure 2.20

I

Prochaetoderma caIifornicum Schwabl, 1963: 265-267, figs. 4-7.--Salvini-Plawen, 1992: 323. l

Material Examined. California, Santa Maria Basin, Sta. 5 (8, SBMNH); Sta. 62 (5) (USNM); Sta. t

R-6 (1) (probably collected dead, USNM).--Southern California Bight, South of Santa Cruz Island, 1,756 II

m (4) (LACM 76-253); San Pedro Basin, 536-689 m (6) (LACM 77-204, 77-275, 77-202, 77-274, 77-261)

and 693 m (5) (lectotype, LACM 2091, and 4 paraleetotypes, LACM 2092).

Description. Length 4.0 mm or less, trunk length and width up to 2.5 x 0.7 mm, posterium usually I

less than 1.0 mm long, width 0.3 mm or less (Fig. 2.20A-C). Oralshield small, each side of pair 0.1 mm high

x <0.1 mm wide (Fig. 2.20B). Spicules orientated dorsoposteriorly from ventral midline (Fig. 2.20B), 1

becoming anterior-posterior on posterium; with single row of long spines surrounding mantle cavity (Fig. II

2.20]3, C). Spicules with long base separated from blade by an indented waist, with blade twisted in relation

to base and bent slightly outwards (Fig. 2.20K, L), up to 6 pm thick; from dorso-anterior trunk, up to 100 prn l_

long, base up to 32 _-n wide (Fig. 2.20H); from mid-dorsal trunk, up to 170 jarnlong x 32 _n wide (Fig. I

2.20J); from junction of dorsal trunk with posterium, up to 185 pm long and 32 txmwide (Fig. 2.20K); and

from midventral trunk, <160 parnlong to <30 jamwide (Fig. 2.20M). Jaws to 447 tamlong x 348 _m wide x 1

104 Farothick (Fig. 2.20A, F, G); radula tooth length about 130 wn (Fig. 2.20D); lateral extension of radular II

membrane 36 _rn (not figured); central plate curved and somewhat pointed at each end, 38 _na x 8 _rn (Fig.

2.20E). il

Biology. Spathoderma caIifornicum was collected from the Santa Mafia Basin in silt and sandy silt

with up to 34% sand and <15% clay. Species of Prochaetodermatidae are often one of the numerically dominant

forms in the deep sea at 1,500 m or more. This dominance apparently does not occur in the shallower waters Ill

off the California coast (Blake, 1993: Vol 1, pp. 39-41). In the Southern California Bight the species occurred I

at the same stations as Chaetoderma hancocki, C. nanulum, C. scabrum, Falcidens hartmanae, E longus,

and Limifos R sor fratula. I emarks. Spathoderma californicum is distinctive and easily differentiated from the only other

"tailed" species in the Santa Mafia Basin, Falcidens hartmanae, by the lack of an anterior constriction,

presence of jaws, and spicules that spiral from ventro-anterior to dorsoposterior. Spathoderma is not II

synonymous with Prochaetoderma (Salvini-Plawen, 1992), species of which have flat spicules with base I

and blade oriented in the same plane.

Distribution. An upper continental slope species, perhaps restricted to areas south of Monterey !

i

Bay between 500-1,800 m. Closely related species occur off the Farallon Islands and Oregon coast. 411

I

!

!

!

!
!

!

._.-_-

,, ,_._:_

i at + pt _ 1

1.0mm

| B •

ms

!

,, o_ ,/1,,,_1

I

I

i F o.Imr. G H J K L M

!

Figure 2.2,0, Spathoderma catifornicum (Schwabl): A, paralectotype (LACM 2092), spicules dissolved, jaws

' U evident through cuticle; B, C, specimen in ventral (B) and dorsal (C) view (SMB Ph. I Sta. 62,

|

USNM); D-G, radula apparatus of paralectotype; D, distal and proximal ends of two teeth; E, central i

plate; F, G, jaws in side and medial views; H-M, spicules of specimen B, C; H from dorso-anterior,

J from mid-dorsal trunk, K, L from region between trunk and posterium, M from midventral trunk. |

I 45
!

Literature Cited I

Blake, J. A. 1993. Benthic soft-substrate community ecology of the Santa Maria Basin and Western Santa I

Barbara Channel. In: Blake, J. A. and A. L. Lissner (eds.), Taxonomic Atlas of the Santa Maria |

Basin and Western Santa Barbara Channel. Volume 1:33-45.

Boss, K.J. 1982. Mollusca. In: Parker, S.P. (ed.). Synopsis and Classification of Living Organisms. McGraw- i

Hilt, New York. pp. 945-1166. 411

Buckland-Nicks, J. and E-S. Chin. 1989. Spermiogenesis in Chaetoderma sp. (Aplacophora). Journal of lm

Experimental Zoology 252:308-317. n

Heath, H. 1911. The Solenogastres. Reports on the Scientific Results of the Expedition to the Tropical

Pacific...by the "Albatross"....Memoirs of the Museum of Comparative Zoology 45 (1): 1-179. 1

JIB

Hyman, L.H. 1967. The Invertebrates. Vol. VI. Mollusca I. McGraw Hill, New York. 792 pp.

Odhner, N.H. 1921. Norwegian Solenogastres. Bergens Museums Aarbok 1918-1919, nr. 3:1-86. 1

J

Pruvot, G. 1890. Sur le d6veloppement d'un Solrnogastre. Comptes Rendus hebdomadaires des Srances de

l'Acadrmie des Sciences 111: 689-692. m

Prnvot, G. 1891. Sur l'organisation de quelques Nromrniens des c6tes de France. Archives de Zoologie I_

Exprrimentale et Grnrrale (ser. 2) 9:699-805.

m

Salvini-Plawen, L. v. 1978. Antarktische und subantarktische Solenogastres (eine Monographie: 1898-1974). I

Zoologica (Stuttgart) 44:1-315.

Salvini-Plawen, L.v. 1985. Early evolution and the primitive groups. In: Trueman, E.R. and M.R. Clarke

(eds.). The Mollusca. Vol. 10. Evolution. Academic Press, Orlando, FL. pp. 59-150. II

Salvini-Plawen, L. v. 1992. On certain Caudofoveata from the Vema-Expedition. In: Gittenberger, E. and J. i

Goud (eds.), Proceedings of the 9th International Congress, Unitas Malacologica. Leiden. pp.317- I!

333.

Salvini-Plawen, L. v. 1993. The validity of Chaetoderma montereyense Heath along with Ch. argenteum _l

Heath (Mollusca: Caudofoveata). Veliger 36:405-412. Ig

Scheltema A. H. 1972. The radula of the Chaetodermatidae (Mollusca, Aplacophora). Zeitschrift f/Jr Ill

Morphologie der Tiere 72:361-370. I

Scheltema A.H. 198t. Comparative morphology of the radulae and alimentary tracts in the Aplacophora.

Malacologia 20:361-383. l

t

Scheltema A.H. 1987. Reproduction and rapid growth in a deep-sea aplacophoran mollusc, Prochaetoderma

yongei. Marine Ecology-Progress Series 37:171-180. II

Scheltema A.H. 1988. Ancestors and descendents: relationships of the Aplacophora and Polyplacophora. g

American Malacological Bulletin 6: 57-68.

Nil

Scheltema A.H. 1993. Aplacophora as progenetic aculiferans and the coelomate origin of mollusks as the 1

sister taxon of Sipuncula. Biological Bulletin 184:57-78.

Scheltema A.H. In press. Class Aplacophora. In: Fauna of Australia. Vol. 5. Mollusca. Australian Biological i

Resources Study, Australian Government Publishing Service, Canberra, ACT. II

I
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I Scheltema, A. H., J. Buckland-Nicks, and F.-Sh. Chia. 1991. Chaetoderma argenteum Heath, a northeastern

Pacific aplacophoran mollusk redescribed (Chaetodermomorpha: Chaetodermatidae). Veliger

i 34:204-213. Scheltema, A. H. and Jebb, M. 1994. Natural history of a solenogaster mollusc from Papua New Guinea,

Epimeniaaustralis (Thiele) (Aplacophora, Neomeniomorpha). Journal of NaturalHistory 28:1297-

I 1318.

Scheltema, A.H., M. Tscherkassky, and A.M. Kuzirian. 1994. Aplacophora. In: Harrison, F.W. and A.J.

Kohn (eds.). Microscopic Anatomy of Invertebrates. Vol. 5. Mollusca: Aplacophora, Polyplacophora,

I and Gastropoda. Wiley-Liss, New York. pp. 13-54.

Schwabl, M. 1961. Crystallophrisson (=Chaetoderma) hartmani, nov. spec., eine neue Aplacophore aus

i dem Ostpazif'tk. Zoologischer Anzeiger 166:258-277.

Schwabl, M. 1963. Solenogaster mollusks from southern California. Pacific Science 17:261-281.

I Thompson, of T.E. 1960. The development ofNeomenia carinata Tullberg (Mollusca Aplacophora). Proceedings the Royal Society of London B 153: 263-278.

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iIIIiiIIIIIiIIiII
!

I 3. CLASSPOLYPLACOPHORA

| by

Douglas J. Eernisse 1

!

I Introduction

Chitons (Mollusca: Polyplacophora) are an ancient lineage of molluscs recognizable by their

t distinctive eight overlapping shell plates called valves. All valves articulate to form an oval to elongate dorsal or ventral profile (Figure la-e). In their normal attached position, the valves are highest along the

chiton's axis of bilateral symmetry, with left and right eaves of the medial (intermediate) valves sloping

I down laterally, more or less steeply, from either side of this central crest. The middle (fourth and fifth)

valves are the widest, with others becoming progressively narrower toward the roughly hemispherical head

and tail valves.

I When chitons hard substrates with their mucus-covered and muscular foot.

alive, cling tightly to

The foot and other ventral soft tissues are hidden from view by the chiton's dorsal-plated armor, which itself

is embedded in a flexible and muscular tissue known as the girdle. The girdle's distal edge and underside

I conform to the substrate, while its dorsal surface be ornamented, for (ventral surface) tightly can variously

example, with a tunic of scales (Figure 3-1 a), elaborately branching bristles, or needle-like to stout spines.

Chitons are muscular animals. Besides their valves' f'u-mmounting in the girdle tissue, each of their eight valves is firmly attached on its inner (ventral) surface by a double-cord pair of muscle groups. Living

monoplacophorans have a similar arrangement of eight paired muscle groups (Wingstrand, 1985). Most

i species will roll themselves into a ball when dislodged or when submerged in f'Lxativesif muscle relaxation is neglected prior to treatment. When preserving chitons as biological specimens, the chiton should first be

relaxed in a solution of 7.3% magnesium chloride, and then bound onto a wooden tongue depressor or glass

slide by wrapping it longitudinally, such as with thin strips of torn nylon hosiery, before placing it into the

I fixative.

The valves' outermost (dorsal) layer, the tegmentum, is often brightly colored, and is penetrated by

i numerous sensory organs dispersed in regular patterns across the valve surface. These organs may be visible on or between minute raised pedestals or ridges that give the valve a granular or sculptured appearance.

These sensory organs, the esthetes, arise from an intricate series of diverging nerve channels penetrating the

i tegmentum, originating as primary nerve bundles around the tegmental margin. In most chiton species, these nerve bundles are routed to the dorsal surface through slits at the valves' distal margins. As can be

seen in the disarticulated valves of most chitons (except lepidopleurids), these slits divide the insertion

i plates (artChitons iculamearentum) anexclusively into "teeth."marine group, numbering just over a thousand recognized species including

about 830 extant species as well as those known only as fossils. Many species have a maximum adult size

i lPacific ess thanshores, 1 cm length, Cryptochiton butlengths stelleri of several , can reach cm are33alsocm clength. ommon,Over and ahalf shallow-water of all speciesinhabitant live in intertidal of northernto

I

Laboratory of Molecular Systematics, Smithsonian Institution, Washington, D.C., USA, and Department of Biology

i MH 282, California State University, Fullerton, California, 92634-9480.

I 49

!

I shallow subtidal habitats, but chitons are also present in deeper habitats wherever suitable hard substrates

exist, and some even live in the deepest ocean trenches. Chitons attach and creep over hard substrates using

i their majorbroad (second) stickylateral foot.radular They usually teeth. Their feed mantle by scraping cavityorisbiting u-shaped, with extending several pairs awayof from magnetite-reinforced their mouth and

surrounding either side of the foot until it is joined in the anal region posterior of the foot (Figures lc-e).

i There are multiple gills on either side of the foot, with each gill row hanging like a curtain from the mantle cavity roof. In the suborder Lepidopleurina (e.g., Leptochiton), the left and right gill rows form a continuous

hemispherical arch restricted to the posterior mantle cavity surrounding the anus (Figure le). In contrast,

i the more familiar chitons comprising the suborders Ischnochitonina and Acanthochitonina have laterally placed gill rows with considerable separation between the last gill in each row (Figures lc-d). Other extant

chitons also differ from lepidopleurid chitons in possessing more extensive and "slit" distal extensions of

the valves, anchored in the girdle, known as insertion plates. Microscopic distinctions include the greatly

I acrosome sperm, as as more spine-, cup-, or

reduced of their well the much elaborate cone-like extracellular

egg "hulls" that cover their eggs.

•i by PilsbryChiton (1892-94) anatomyand was Thielerecently (1909-1910) reviewedarebybeing Eernisse updatedandinReynolds an ongoing(1994). seriesSystematic by Kaas andmonographs Van Belle

(1980, 1985a, 1985b, 1987, 1990, 1994). Kaas and Van Belle have largely followed the classification proposed

i by Van Belle (1983, 1985) and, with minor exceptions, this classification is also followed here and in a

worldwide geographic distribution and nomenclature database (Eernisse, in press).

The current classification includes all living chitons in a single order, Neoloricata. The most familiar

I and Mopaliidae, conspicuous Lepidochitonidae, chitons belong toandtheseveral subordersotherIschnochitonina common families) (including and Ischnochitonidae, Acanthochitonina Chitonidae, (including

Acanthochitonidae and Cryptoplacidae). Members of a third suborder, Lepidopleurina, mostly live in deeper

I water, have Ecological white to tannish tegmental coloration, and differ from the other chitons as discussed above. studies of chitons have mostly focused on shallow water species. The diet of chitons

varies, depending on the species, with a wide variety of plant and animal species consumed by chitons. In

I intertidal of diatoms,communities, but also detritus chitons and are colonial mainlyanimals. herbivorous, Some feeding on fleshy or crustose algal blades, or films intertidal chitons exhibit homing behavior (Thome,

1968; Mook, 1983; Chelazzi et al., 1987), and some species excavate home depressions in a manner similar

I toexcavating some limpet the depression species, probably further bywithsoftening their radula. the substrate Chitons with can also acidichavesecretions an important from role theirinfoot, determining and then

community ecological structure, in some cases benefitting from the presence of other chitons when their

I feeding activities promote the growth of preferred algal species (Dethier and Duggins, 1984; Duggins and

!

Figure 3.1. External anatomy of chitons,from Eernisse andReynolds(1994).Figures oriented with anterior end

i at the top.A.Dorsal view of Chiton tuberculatus(Ischnochitonina:Chitonidae). c, central area (note the anterior portion of tail valve with same sculpturing pattern); g, girdle elements (overlapping

scalesinthis case);h, head valve;j, jugum andjugal area; 1,lateral area (note head valve and posterior

part of tail valve have similar sculpturing);t,tail valve. B. Ventral view of disarticulated valves of

I Chiton squamosus, a, apophyses; ip, insertion plates; js, jugal sinus; s, slit in insertion plate of articulamentum shell layer. C. Ventral view of FerreireUa caribbeanensis (Lepidopleurina:

Leptochitonidae). Note posterior placement of gill rows, which are adanal (most posterior gill in

I each adanalrowwithis not interspace, the largest) f,fooandt; g,without ventralinterspace. side of girdle; D. Ventral gr, leftview gill row; of Chiton m, mouth bowenii and.oral Gillplatform. rows are

E. Ventralview ofMopatia hindsii (Ischnochitonina:Mopaliidae).Gillrows are abanal(mostposterior

t gill in each row is largest) with interspace.Scale bars: A, B = 5.5 mm; C-E = 1cm.

I 51
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Dethier, 1985). Compared with the enormous variation known for gastropod radulas, the chiton radula is i

relatively conserved. Yet subtle variations of the radular tooth orientation have been shown to be important

in which types of food a particular chiton species feeds on (Bullock, 1988). The radular tooth shape is also I

sometimes correlated with diet, for example, chitons that feed on crustose coraUine algae have broad shovel- |

like major (2nd) lateral teeth (e.g., Tonicella lineata), and chitons that specialize on deep-water sunken

wood (e.g., FerreireIla spp.) have expanded fifth lateral teeth. Other examples of dietary specialization i

include deep-water sponge feeders (e.g., Warfn, 1991), but there is little evidence that a preference for a II

sponge diet has led to a modification of the radula. Members of Placiphorella (McLean, 1962), and probably

also members ofLoricella, and Spongioradsia, have special notoriety because they feed as ambush predators, i

entrapping mainly small crustaceans as they pass under an uplifted head flap. This carnivorous behavior has |

likely had three convergent origins, because each genus exhibits what is best regarded as a derived trait

within its particular distinct chiton family. I

Chitons have been collected from >7,000 m in some of the deepest oceanic trenches, and have also i

been found associated with deep sea hydrothermal vents (Saito and Okutani, 1990). Vast expanses of deep

sea habitat are composed of soft sediments that would be unsuitable habitat for chitons if it were not for I

some scant hard substrate scattered across the sea floor. For example, chitons have been collected from I

manganese nodules, which are among the only hard substrate available in deep oceanic habitats (Mullineaux,

1986). These chitons probably feed on forarniniferans and other small animals also found on the nodules. I

The ecology of chitons that live in intermediate depths, such as those in the present study (50-250 m), is II

perhaps even less well known. Chitons from these depths tend to be taken incidentally to other dredged

animals, and most recovered chiton specimens are already dead or removed from their natural habitat by the i

time they are identified. Because basic natural history data is generally lacking, there continues to be great II

value for any observations that can be recorded, even when specimens must remain unidentified.

In

Observing External and Internal Features i

The valves and girdle are the most emphasized aspects of chitons because they are the most I

conspicuous features of the outer (dorsal) surface), and the valves commonly have survived as fossils. The

approximately bilaterally symmetrical body of a chiton and the tendency for body parts to be repeated along i

this axis makes references to anatomical features relatively straightforward. The terminal "head" and "tail" II

valves correspond to the ventral mouth and anus, respectively, with "right" and "left" sides normally referring

to the body as viewed dorsally with the head (anterior) valve uppermost. The right versus left distinction is I

not emphasized, however, because right and left sides are approximately mirror images. Figure 3.1 illustrates i

the most important distinctions of relevance to the identification of chitons. It should be emphasized that

although every effort has been made to avoid reference to features of valves, girdle, and radula that require I

their disarticulation (separation) to observe, it is not always possible or efficient to identify chitons from 1

outer appearances alone. After first noting salient external features of the intact chiton (especially gills,

dorsal coloration, and measurements), the disarticulation of chitons can be accomplished by bringing a 1

specimen to near boiling in clean freshwater to which several potassium hydroxide pellets have been added. I

The disarticulated valves are pulled apart with fine forceps before the specimen has fallen apart by itself,

Ill"

and then each valve is well rinsed in distilled water. Valves should be stored dry in separate marked vials. I

Girdle fragments and the radula are pulled gently from the remaining tissue and, after careful rinsing, are 1

either mounted for light or scanning electron microscopy or stored in ethanol for later observation. These

I

procedures will permit a much more careful examination of chiton morphology. ,..

|

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52 i i
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I Systematic Treatment for Polyplacophora Most Likely to Occur in the Santa

Maria Basin Area (Following Van Belle, 1983)

I Class Polyplacophora Gray, 1821

Order Neoloricata Bergenhayn, 1955

I Suborder Lepidopleurina Thiele, 1910

Family Leptochitonidae Dall, 1889

I Leptochiton Gray, 1847 Oldroydia Dall, 1894

Hanleyella Sirenko, 1973

i. Suborder Ischnochitonina Bergenhayn, 1930

Family Ischnochitonidae Dall, 1889

I Subfamily Chaetopleurinae Plate, 1899

Chaetopleura Shuttleworth, 1853 (Pallochiton) Dall, 1879

i SubLepidozona family Ischnochitoninae Pilsbry, 1892Dall, 1889

Ischnochiton Gray, i847 (Stenosemus) Middendorff, 1847

I Subfamily Callistoplacinae Pilsbry, 1893

Callistochiton Carpenter MS, Dall, 1879

I Family Mopalia Mopaliidae Dall, 1889 Gray, 1847

I Placiphorella (Carpenter MS) Dall, 1879

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Glossary i

Abanal. Condition when the largest gill is the Girdle. Flexible, leathery, muscular integument •

most posterior gill of each gill row, located holding the valves in place, often !

beneath valve 7 or 6 on each side of the foot. ornamented with scales, spicules, or hairy

Adanal. Condition when the largest gill of each processes. 1

gill row is intermediate, located beneath Granules. Grain-like elevations of the valve or I

valve 7 or 6 on each side of the foot, with girdle.

progressively smaller gills tapering to the I

posterior and anterior. Hairs. Lengthy string-like comeous processes of ==

the girdle.

Apophyses (or sutural laminae). Paired anterior •

projections of the articulamentum layer of Head flap. A greatly expanded anterior girdle

valves 2-8 articulating beneath the next margin used for trapping passing prey by

some chitons (e.g., Placiphorella). valve in series on either side of the midline. m

Apex. Highest point of each valve coinciding Head valve. (or valve 1) The most anterior valve, I

with the midline, which generally has a semicircular shape

insertion plate. Distal projections of the It

Articulamentum. The inner, white to colored articulamentum layer of valves 1-8 of most I

and semi-porcelaneous shell layer, generally chitons, and which anchor the valves by

projecting past the tegmentum on the sides imbedding into the girdle tissue, am

and front of the valves to form the insertion II

plates and apophyses, respectively. Insertion plate slit. Slit-like divisions of the

insertion plates, corresponding to the

Beak. Central posterior projection when present placement of the nerve bundles that

of the posterior margin of an intermediate innervate the esthetes. It

valve. Insertion teeth. Unslit parts of the insertion Ill

Central area. Upper surface of an intermediate plates, l_

valve, lying centrally and sometimes

differing in sculpture from each valve's Intermediate valves. Valves 2 to 7, which

generally have a similar shape in contrast to I

lateral areas, the head and tail valves. till

Cleft. Posterior split in the girdle corresponding

to a posterior sinus in the tail valve. Interspace. Condition when the left and right gill 1

rows are separated, that is, restricted to the II

Cteuldium. Primary molluscan gill as the chiton lateral portions of the pallial groove, with

gill is commonly regarded (excludes the the last gill in each row at some distance m

secondary gilt lappets found in some from the anus. Opposite is no interspace, I_

molluscs but not chitons), when each gill row extends to near the anus.

==

Esthete. Numerous tiny sensory/secretory organs Jugal area(or jugum). Longitudinal ridge along •

found in the upper exposed tegmental shell the midline in the central areas of the

layer of all chitons, intermediate valves, generally referred to

only when it has sculpturing distinct from

Gill Multiple feather-like respiratory structures the rest of the central area, as in Ill

hanging in paired rows from the roof of the Acanthochitonidae.

pallial groove on either side of the foot, with

each gill made up of a main axis bearing Jugal lamina Extension of the articulamentum in l[

alternating series of oval, thin, ciliated the jugal sinus which connects the

laminae, tapering in size towards the apophyses.

proximal tip of the gill. I
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I Jugal sinus. Depression between the apophyses. Rib. Raised bands of sculpturing, commonly in

reference to the sculpturing or valves or

Lateral areas. Paired triangular-shaped regions girdle elements.

I ointermediate f the upper valve valve surface that are omore f an or less Riblet. Fine ribs.

distinguished from the central area by their

I often diagonal sculpturing. Scales. Flattened calcareous girdle elements, often superimposed and imbricating as in a

Major laterals. Second of (normally) eight coat of armor.

i lateral "tooth" pairs of each of about 30 to 200 rows of the chiton radula; the main Slit formula. The observed number or range of

functional feeding structures of the radula, numbers of insertion plate slits, standardly

conspicuous because of their black, recorded for head/(one side of) intermediate/

I tail valves (e.g., 8-10/1/12-14 where 8-10 magnetite-capped, cusps. slits were observed in the head valve, 1 on

Muero. Generally used to indicate a small each side of each intermediate valve, and

I pointed point, butprocess normallyendingusedinina chitons sharp rigid in 12-14 on the tail valve).

reference to the "beak" of the tail valve, Spicule. Sharp-pointed, blunt to needle-like,

I which anterioris(subcentral) mostly near along centertheor just midpoint slightlyof calcareous enough to require elementmicroscopic of the girdle,examination. small

the tegmentum's midline, but can also be Spine. Sharp-pointed calcareous element of the

I somewhat posterior or even terminal, girdle, large enough to be conspicuous to the

Pallial groove, The u-shaped cavity on the lateral eye.

and posterior sides of the foot posterior to Sutural hair. Hairs occurring characteristically at

I platform, by the valve sutures.

the oral bounded the ventral

girdle surface, so named because of the

Sutural spines. Clusters of spines occurring

presence of paired gilt rows in this cavity.

I Plate. See valve. Acanthochitona characteristically). at the valve sutures (e.g.,

Pleural areas. Side slopes of the central areas of Sutural laminae. See apophyses.

I an intermediate valve (not including the jugal region). Tail valve (or valve 8). The most posterior valve.

I Post-mucronal tail valve between slope. Slope the mucro of theandmidline the girdle, of the Tegmentum. (dorsal) exposed The oftenshell brightly layer colored of chitons, upperthat

best viewed from a lateral orientation, is partly organic and partly inorganic and

can be sculptured with granules, pustules,

I Quinetmx. Arrangement of five entities in a riblets, or ribs.

square, having one in each comer and one in

the center. Tubercles (or nodules). Small, nob-like

i Radial. Extending as rays from the center. projections.

Valve. One of eight shell plates characteristic of

Radula. Rasp-like ribbon armed with rows of chitons.

I teeth and plates; the characteristic feeding

organ of most molluscan groups including

all chitons, which normally have 17 teeth

I (or plates) per row.

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Taxa Treated in This Atlas i

Species Examined from the MMS Santa Maria Basin Collections: I

l

Leptochiton rugatus (Carpenter in Pilsbry, 1892)

Hanleyella oldroydi (Bartsch MS, Dall, 1919) 1

Lepidozona scabricostata (Carpenter, 1864) II

Lepidozona retiporosa (Carpenter, 1864)

dml

Callistochiton paImulatus Carpenter MS, Dall, 1879 1

Mopalia phorminx Berry, 1919

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Additional Species Likely to be Encountered in the Study Area: I

Leptochiton nexus Carpenter, 1864 im

Oldroydia percrassa (Dall, 1894) I

Chaetopleura (Pallochiton) gemma Carpenter MS, Dall, 1879

Lepidozona mertensii (Middendorff, 1847) I

m

Lepidozona interstincta (Gould, 1852)

Lepidozona sinudentata (Carpenter in Pilsbry, 1892)

Lepidozona willetti (Berry, 1917) II

lschnochiton (Stenosemus) albus (Linnaeus, 1767)

Callistochiton crassicostatus Pilsbry, 1893 1

II

Callistochiton decoratus Carpenter MS, Pilsbry, 1893

Mopalia imporcata Carpenter, 1865 I

Placiphorella II pacifica Berry, 1919

Does not include species restricted to shallow depths (< 30 m). I

I

Key to the Polyplacophorans of the Santa Maria Basin !

This key should be generally useful for chitons collected from deep water (> 30 m) off the California

coast, and may also suffice for those collected further to the north, at least along the coast of Oregon and Ill

outer coast of Washington. No key of similar emphasis has been previously published. As for the preceding I

listing of chiton species likely to be encountered in the study area, the following key does not treat the

considerable number of west coast chiton species that are known only from depths of less than about 30 m. 1

There is no up-to-date key available for intertidal and shallow subtidal chitons of southern California, but II

there are a number of valuable sources (e.g., McLean, 1969; Burghardt and Burghardt, 1969; Smith, 1975;

Haderlie and Abbott, 1980; Putman, 1982; Kaas and Van Belle, 1985a, I985b, 1987, 1990; Kozloff and I

Price, 1987). There is a small amount of overlap in species that axe common along the Baja California |

coastline, but relatively little with species in the Panamic province further south (Skoglund, 1989). Several

reviews of the temperate eastern Pacific members of particular genera have been presented (e.g., Ferreira, m

1978, 1979a, 1979b, 1982; Eemisse, 1986; Waters, 1992), but these have tended to emphasize shallow- 1

water species that are largely unrepresented in the present survey.

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I 1A. Girdle much wider in the anterior (head) region than in the posterior (tail) region; oral region with

conspicuous cephalic lappets extending anteriorly; tegmentum of intermediate valves at least four

i times projecting wideralong than long, and depressed in lateral regions; girdle bristles with many calcareous spicules their length (not taken in survey material) ......................... PlaciphoreUa pacifica

lB. Girdle equally wide in head and tail region; oral region with a simple platform surrounding the

I mouth; convex lateral tegmentumslopes;ofgirdle intermediate bristles, valves if present, lesswithout than four conspicuous times as wide calcareous as long, spicules with along straighttheiror

length ............................................................................................................................................... 2

I 2A. Conspicuous flexible, golden to dark brown hairs on girdle .......................................................... 3

i 2B. Girdle with short pointed spicules, small glassy strap-like bristles, slender spines, or scales, but no conspicuous and flexible hairs ........................................................................................................ 4

I 3A. Girdle valve with bristles aboutwispy, 8-10 many heavy asradiating long asribs, the girdle interspersed is wide,byeach one with or more sparseradiating lateral rows branches; of shorter head

but distinct pustules; intermediate valves with the two heaviest ribs defining the extent of each

I• lateral central region, areas withagain distinct interspersed longitudinal by one ribbing, or more betweenradiating which rows is a dense of shorter lattice ofbutsomewhat distinct pustules; irregular

and much finer lateral subribs; mucro subcentral; tegmentum usually white (see Figures 3.6 A-D)

I ............................................................................................................................. Mopalia phorminx 3B. Girdle bristles stout, mostly shorter than the girdle width, with dense branching along their length

giving them a bushy appearance; head valve with about 10 heavy radiating ribs, and intermediate

I valves with the two heaviest ribs defining the extent of each lateral region, but pustules between these ribs are not set off in well spaced, strictly radial, rows; central areas with distinct longitudinal

ribbing, between which is a quite regular lattice of much finer lateral subribs; mucro nearly terminal;

I tegmentum usually golden (see Figures 3.6 E-H) .................................................. Mopalia imporcata

i 4A. Gill rows without an interspace, with left and right rows forming a nearly continuous curtain in the posterior part of the pallial groove near the anus; tegmentum whitish, tan, or drab grey, but not

brightly colored; disarticulated valves without insertion plates ...................................................... 5

I 4B. Gilt not extending rows with toan near interspace, the anus; withtegmentum left and right coloration rows onbright either orsidedrab; of thedisarticulated foot and wellvalves separated, with

insertion plates extending laterally in the intermediate valves, anterior in the head valve, or posterior

in the tail valve ................................................................................................................................ 8

5A. Jugat region of each intermediate valve conspicuously raised with its broad anterior end (away

i from apex) characteristically projecting forward for almost half the length of the next valve' s central region; jugum of posterior (tail) valve likewise conspicuously raised and coming to a point at the

mucro; valves heavy with coarse, somewhat irregular, patterns of sculpturing; body often much

I longer than 15 ram, up to a maximum of about 28 ram; girdle encroaching between valves (not taken in survey material) .................................................................................. Oldroydia percrassa

5B. Jugal region of the intermediate and tail valves not conspicuously raised relative to the central

I regions; valves delicate with fine patterns of mostly regular sculpturing; body seldom (if ever) as long as 15 mm, usually less than 10 mm; girdle not encroaching between valves ......................... 6

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6A. Lateral regions of intermediate valves and head and tail valves with randomly arranged, rather I

prominent, pustules, especially at the extreme margins; lateral regions not raised but with sculpturing

distinct from the central regions, which have regularly arranged longitudinal rows of much smaller

pustules; dorsal side of girdle with many tong, smooth, calcareous needles up to 400 _rn scattered I

in tufts among much shorter spicules (see Figure 3.3) ..................................... HanleyeIla oldroydi

6B. Lateral regions of intermediate valves and head and tail valves with uniformly fine granules over 1

entire tegmentum, arranged in regular rows, radiating in lateral areas and longitudinal in central

areas, which otherwise are not distinguishable; dorsal side of girdle with small elongate spicules

generally less than 70 jamlength, longer spines up to 400 pro, if present, not generally occurring in i

tufts .................................................................................................................................................. 7 II

i

7A. Postmucronal slope straight; dorsal girdle elements mostly rectangular scales with 13-16 riblets •

and not longer than about 60 Wn, although some ribbed spicules occur, especially in valve junctions; i

foot may be reddish in living specimens; black caps of major lateral radular teeth unicuspid and

quite elongate (see Figure 3.2) ......................................................................... Leptochiton rugatus I

m

7B. Postmucronal slope concave; dorsal girdle elements primarily smooth spicules, mostly shorter than

70 _m, with scattered needlelike spines up to at least 400 vm; foot not known to be reddish in living m

specimens; black caps of major lateral radular teeth bicuspid and only moderately elongate (not mR

taken in survey material) ...................................................................................... Leptochiton nexus

w

8A. Head and tail valves with very prominent ribs ................................................................................ 9 I

8B. Head and tail valves without prominent fibs, although there may be distinct radiating rows of globular

tubercles ......................................................................................................................................... 11 1

9A. Tail valve prominently bulging well above the other valves, shaped like a fist; rounded mucro near I

valve VII and not raised relative to the highly convex postmucronal slope ............... CalIistochiton !1

palmulatus

9B. Tail valve not prominently bulging, mucro subcentral to terminal, above the postmucronal slope. I1

.................................................................... ,, ................. ,.., ............................. , ......... ,,+ .................. 10 II

II

10A. Mucro high and terminal, postmucronal slope nearly vertical; head valve with about seven stout •

ribs, each with several pustular subribs (not taken in survey material) ............................................

............................................................................................................. CaUistochiton crassicostatus

10B. Mucro intermediate height and subcentral, postmucronal slope straight to slightly convex; head 1

valve with about eleven scalloped ribs without subribs (not taken in survey material) ...................

.................................................................................................................... Callistochiton decoratus 1

J

11A. Lateral areas of intermediate valves andhead andtail valves with weak sculpturing, similar to that

of central areas; body length shorter than 20mm .......................................................................... 12 _l

i

11B. Lateral areas of intermediate valves with rows of prominent round tubercles; head valve and posterior

part of tail valve sculptured as in lateral areas; body length sometimes longer than 20mm ........ 13

I

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I 12A. Girdle scales overlapping but conical and slightly bent, not flattened rectangular, and much longer

than wide (170 x 100pro); apophyses not connected by a jugal lamina (requires disarticulation);

I tegmentaI coloration white, often smeared with dark deposits, especially along the posterior margins of the valves (not taken in survey material) .................................. lschnochiton (Stenosemus) albus

12B. Girdle scales overlapping and approximately rectangular, wider than tall (170 x 270 pro); apophyses

I connected are pure white, by ajugal with lamina other specimens that is notched of variable where itcolors connects including on eachcream, side; only yellow, occasional orange, specimens brown, or

olive (not taken in survey material) ............................................................ Lepidozona interstincta

I 13A. Girdle with sparsely scattered small, strap-like glassy bristles (requiring microscopic examination),

without imbricating scales; apophyses not connected by a jugal lamina (requires disarticulation);

I tegmental color more rarely, for a black, spotted with white, tail valve;

orange OF, green, except

typically with tiny black pigment spots scattered across tegmentum (not taken in survey material)

.................................................................................................. Chaetopleura (Pallochiton) gemma

I 13B. Girdle with prominent overlapping scales; apophyses connected by a jugal lamina that is usually

notched where it connects on each side; tegmental color varies but tail valve not characteristically

black and spotted with white; without tiny black pigment spots in the tegmentum ..................... 14 !

14A. Central areas of intermediate valves with longitudinal to arching diagonal rows of conspicuous but

I shallow pro), nearlypits,aswithout tall as wide, conspicuous with faintintervening transverse longitudinal ridges and notridges; cappedgirdle by nipples; scales small color of(lesstegmentum than 150

usually uniform, and brown but occasionally tan or apricot, or a broadly banded combination of the

I two see Figure (note: tubercles 3.5) ............................................................................................... and even central area pitting may be difficult to observeLepidozona in some specimens; retiporosa

14B. Central areas of intermediate valves with distinct longitudinal ridges, sometimes with shallow pits

I in between; girdle scales small (100 pro) to large (450 pin), usually wider than tall, with or without ribbing and with or without nipples at the top .............................................................................. 15

I 15A. Ridges prominent in all or much of the central areas of intermediate valves, forming a heavy lattice

extending across the apex .............................................................................................................. 16

I 15B. Ridges generally indistinct in central part of central areas, not latticed, although lateral portions are latticed ........................................................................................................................................... 17

I 16A. Sculpturing of lateral areas, head valve, and posterior portion of tail valve dominated by regular

rows of globular pustules; girdle scales strongly convex, smooth or only weakly striated, crowned

with a nipple that is not strongly set apart from the rest of the scale at its base; body length to as

I large as 50 mm (not taken in survey material) Lepidozona mertensii

16B. Sculpturing of lateral areas, head valve, and posterior portion of tail valve highly variable, from

granular irregular to nearly smooth, but usually without regular rows of globular pustules; girdle

I scales rectangular and only slightly convex with about 10-13 longitudinal striations, not capped by

a nipple; body length not usually exceeding 20 mm (not taken in survey material) ........................

i ..................................................................................................................... Lepidozona sinudentata

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17A. Head valve with 20-40 ribs; intermediate valves not beaked; girdle scales strongly convex, crowned I

with a strongly ribbed nipple that rises distinctly from its base (in those scales where it has not been

broken off); tegmental color usually uniform reddish brown (not taken in survey material) ..........

............................................................................................................................ Lepidozona willetti II

17B. Head valve with 32-50 ribs; intermediate valves with small but distinct beak; girdle scales only

moderately convex, without a nipple but ornamented with about 15 longitudinal fibs; tegmental II

color uniform orange brown to creamy white (see Figure 3.4) ................ Lepidozona scabricostata

Descriptions of Species I

II

Family Leptochitonidae Dall, 1889 U

Genus Leptochiton Gray, 1847 •

Subgenus Leptochiton sensu stricto

Type Species: Chiton cinereus Montagu, 1803, not Linnaeus, 1767 (=Chiton asellus Gmelin, 1791), by m

subsequent designation, Gray, 1847.

Diagnosis. Small oval to elongate oval bodies, valves rounded and thin, lateral areas hardly elevated, n

tegmentum finely granulose, with granules in lines or quincunx. Mucro submedian, girdle clothed with g

small scales, sometimes interspersed with spicules, or wholly spiculose, no insertion plates as in other

members of the family, gill rows adanal without interspace, as for other members of the suborder (based on 1

Ferreira, 1979; Van Belle, 1983). [At present, there is no evidence for the monophyly of this assemblage. HI

The approximately 70 members of the subgenus are grouped because they lack the distinctive, much larger,

tail valve of subgenus Parachiton Thiele, 1909, or the scattered silky hairs that extend between the valves in m

the monotypic subgenus Pilsbryella Nierstrasz, 1905, or the distinctive characteristics of other genera in J

this family, including Lepidopleurus (Leach MS) Risso, 1826, Oldroydia DalI, 1894, and HanleyeIla (see

below).] I

Leptochiton rugatus (Carpenter in Pilsbry, 1892)

Figure 3.2 I

Leptochiton rugatus (Carpenter MS) Dall, 1879 (nomen nudum). •

[] Lepidopleurus internexus Carpenter in Pilsbry, 1892.

Lepidopleurus alascensis Thiele, 1909.

See Ferreira (1979) and Kaas and Van Belle (1985a; 1994) for extensive synonymies. I

Material Examined. The syntype specimens, and many lots from CAS and personal collections.

California: Santa Mafia Basin, Phase I Hard-Substrate Station BRA 16 (2 specimens, 91.5-123 m) and •

Station BRA 20 (2 specimens, 90-130.5 m). HI

Description. Animal to about 16 mm maximum length, with oval to elongate profile; dorsal elevation Ill i

moderate, with intermediate valve profile well rounded, without central ridge, without beak; tegmental 1 i

coloration white to cream, occasionally colored brown, black, or orange by environmental deposits;

tegmentum sculptured with f'me granules, forming fine longitudinal ribs in central areas, and fine radial fibs II

in somewhat raised lateral

areas; articulamentum white, apophyses small, triangular (or truncated in tail I
!

I valve), and well separated; no insertion plates (as for family); girdle narrow, dorsal surface with rough

granular appearance, covered with scales of varying shape, from nearly rectangular (about 60pro long) to

i elongate blunt curved or straight spicules, with bunches of spicules (about 140 _tn long) especially pronounced at valve sutures (these require magnification to observe); radula with unusually large number of closely

spaced tooth rows; girdle scales mostly with longitudinal ribbing; gills adanal without interspace (as for

i suborder), rarely more than 10 per gill row; foot and gills can be dark magenta red color from tissue hemoglobins (at least in shallow-water specimens); major lateral teeth of radula are unicuspid, elongate,

and sharply pointed.

I Leptochiton Remarks. (e.g., theLeptochiton European rugatus L. asellusdiffers ), in having from most numerous, other chitons, closely including packed, rows otheroftypical teeth inmembers its radula. of

The major lateral teeth are nearly touching and are hook-like, not broad as in most chitons (c.f. the tricuspid

I major distribution lateralsofofLthis asellus distinctive and many radularwest morphology coast intertidal is mostly chitons). unexplored. The functional significance and taxonomic

Eernisse et al. (1988) have documented another interesting attribute of the biology of L. rugatus. It had

I of buried ten been in anoxic observedmud,that haveL. rugatus a reddish-collected to magenta-colored intertidally, typically foot. Eemisse from ettheaIundersides . demonstratedof large that boulders this was

due to the presence of tissue hemoglobins, which is the first time hemoglobins have been found in chiton

I tissues obervedapart in the fromgills. theirHowever, normal presence red-footedin Lthe. rugatus buccal have mass never (wherebeenthe radulaeportedisfrom produced). subtidal Theydepths. were This also

may be because most subtidal collections are preserved before being examined, which results in loss of the

I red difference coloration, couldbutconceivably it may also reflect be an indication the habitatthat difference, the intertidal or could L. rugatus also indicate differ inthat thisintertidal attribute.LIf. rugatus so, this

are not the same species as the subtidal ones. There is not much about the valve or girdle morphology that is

I distinctive, sporadic occurence so crypticofspecies L. rugatus are at. least Thoseplausible. interestedAninobstacle pursuingto the answering systematics these ofquestions L. rugatus is themight generally also

consider intertidally occurring Southern Hemisphere species ofLeptochiton, also reported to have a red foot

I (Ewidest ernissegeographic et al., 1988). distribuSimi tionlars toknown its wfoider chiton depth sdis , with tribuatiomostl n, Ly. rugatus continuous alsorang is reeported extending to have fromonetheofGuthelf

of California, up the west coast, across the Aleutian Islands, and down to South Korea. Contrary to their

i earlier (1985a) view, Kaas and Van Belle (1994) have recently concluded that some of the far western Pacific specimens formerly considered by Ferreira (1979b) as L. rugatus are instead L assimilis Thiele,

1909. Sirenko and Scarlato (1983) had earlier reached this same conclusion. However, Kaas and Van Belle

i do not appear to extend this change of view to the South Korean record (Dell'Angelo et al., 1990).

I

Figure 3.2. Leptochiton rugatus (Carpenter in

i Pilsbry, 1892). Dorsal view of specimen,6 mmlength,from Bah'a

SanLuis Gonzaga,Baja Califomia,

I Mexico.

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Chitons all have nonfeeding larvae whose pelagic existence is relatively brief (Eemisse, 1988), and I

thus do not tend to have as wide of a distribution as marine animals with longer pelagic larval stages

(Eernisse, in press). If the reported distribution is accurate, then L. rugatus is perhaps the most widely •

distributed of the richfauna of chiton species present in the northern Pacific. It would be extremely interesting, l

albeit difficult to achieve, to apply molecular-based methods of comparison to individuals throughout the

range ofL rugatus. This would enable an assessment of the degree of genetic continuity between populations mum

living at the extremes of their distribution and at very different depths. il

Type Locality and Type Specimens. Originally, "Monterey, California, to Todos Santos Bay,

Lower California" but restricted to "near S. Tomas River, Lower California," Mexico [31°32'N; 116°26'W], I

as indicated on a label with the syntypes (Ferreira, 1979). Three syntypes, including 2 intact and one II

disarticulated (ANSP 35586).

Habitat. From the intertidal, sometimes under large boulders submerged in anoxic mud, e.g., San •

Juan Is., Washington (Eemisse et al., 1988), or with Stenoplax conspicua [(Carpenter MS) Pilsbry, 1892]

under rocks at Bird Rock, San Diego Co., California (Eernisse, pers. obs.), to at least 453 m (Kaas and Van

Belle, 1985a). Present material includes two specimens from 91.5-123 m (Station BRA 16, 34°46.5'N n

120o50.2,w) and two specimens from 90-130.5 m (Station BRA 20, 34°46'N 120°50'W). II

Distribution. In the eastern Pacific, from Magdalena Bay, and most of the Gulf of California,

Mexico to Cohen Id., Alaska, and the Aleutian Islands. In the western Pacific, from South Korea, and n

possibly parts of the Sea of Japan, the Okhotsk Sea, and the Bering Sea (but see Comments below) (Smith, J

1947: 6; Jakovleva, 1965: 28; Ferreira, 1979; Putman, 1982: 365; Sirenko and Scarlato, 1983; Kaas and Van

Belle, 1985a: 211, but cf. Kaas and Van Belle, 1994: 17; Eernisse etal., I988; Dell'Angelo etal., 1990: 32; n

Vermeij, 1990: 349). I

Hanleyella Sirenko, 1973 I

Type Species: Hanleyella asiatica Sirenko, 1973, by original designation.

Diagnosis. Small ovate bodies, valves thin, lateral areas not elevated, tegmentum granulose, granules :1

becoming larger towards outer margins, flat granules in central areas separated from each other by spaces

larger than their diameters, apophyses rather large for family, sloping gently towards jugal sinus (front •

border of valve), girdle clothed with minute spicules and many large hyaline (noncalcareous) spines, no II

insertion plates as in other members of family, radula with tricuspid major lateral teeth as in many other

chiton genera, gill rows adanal without interspace, as with other members of suborder (based on Ferreira, •

1979; Van Belie, 1983). II

Hanleyella oldroydi (Bartsch MS, Dall, 1919) n

U

Figure 3.3

Lepidopleurus (Leptochiton) oldroydi Bartsch MS, Dall, 1919: 500. n

Leptochiton oIdroydi; Smith, 1947: 6.

Hanleyella oldroydi; Ferreira, 1979: 158; Kaas and Van Belle, 1985a: 190. I

w

Material Examined. The holotype specimen; also many lots at CAS. California: Santa Maria

Basin, Phase I Hard-Substrate Station BRA 6 (> 10 specimens, 54-63 m) and Station BRA 17 (1 specimen, •

160.5-168 m). Ii

Description. Very small species, up to 8.2 mm length and 4.3 mm wide, whitish with strong

sculpturing; randomly arranged, rather prominent, pustules in lateral regions of intermediate valves, lateral I
!

I areas otherwise not raised; central regions with much smaller pustules in regularly arranged longitudinal

rows; distal extremities of head and tall valves with sculpturing similar to extreme margins of lateral regions

i of intermediate valves; mucro subcentral, postmucronal slope straight; apophyses small and triangular, except rounded in tail valve; dorsal girdle with many long, smooth, calcareous needles up to 400 lain in

small bunches at valve junctions and similar tufts scattered among much shorter (40 to 70 fain) and stouter

i spi mature cules; ventral side of girdle covered with fibbed, somewhat smaller, scales; radula with up to about 45 rows of teeth; major lateral teeth tricuspid, with outer cusps relatively small; about 7 gills per side,

with gill rows extending only to about anterior extent of seventh valve.

I characteriRemark stic valve s. This sculpturing. poorly-known It is among speciestheis of mostsmall abundant body size of thebutchitons is easywithin to recogthenize, studyduearea, to itsas

suggested by its numerical dominance in the examined collections. The only other member of the genus,

I Hanleyella its known range asiatica to include , is mostly the Aleutian a northwestern Islands Pacific and southeastern species, although Alaska, about Clark 4,000 (1991)kmhaseastrecently of its previously extended

known range lirrfit.H. asiatica is known to brood its embryos, but nothing is known about the reproductive

I biology of TypHe. oldroydi Loca . lity and Type Specimens. Monterey, California, USA. Holotype (USNM 218767).

Habitat. Recorded from 18 m (Ferreira, 1979) to maximum depths of about 200 m (Smith, 1947;

I Ferreira, 1979). The present material included many tiny specimens from 54-63 m (Station BRA 6, 34°30'N 120°36"¢¢) and a single 6 mm specimen from 160.5-168 m (Station BRA 17, 34°50'N 120°51'W). These

records correspond well with the previously reported median depth of about 100 m.

I Cabo Quint'n, Baja California, [30°17.7'N; 115°54.7'W] to

Distribution. San Mexico Kosciusko

Island, Alaska [55°57'N; 133°40'W] (Smith, 1947: 6; Ferreira, 1979: t59; Baxter, 1983: 68; Kaas and Van

Belle, 1985a: 220). !

! I Figure 3.3. Hanteyella oldroydi (Bartsch MS,

g Dail, 1919). Dorsal view of

specimen,4 mmlength,dredgedoff

I Ensenada,Baja California,Mexico.

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Suborder Ischnochitonina Bergenhayn, 1930 i

Family Isctmochitonidae Dall, 1889 i

Subfamily Ischnochitoninae DaU, 1889

Genus Lepidozona Pilsbry, 1892 I

Type Species: Chiton mertensii Middendorff, 1847, by original designation.

Diagnosis. Of small to large size, tegmentum usually sculptured with radial rows of pustules or I

graniferous ribs on end valves and lateral areas of intermediate valves, with longitudinal riblets and often

latticed interstices on central areas; slit formula: manytl or more/many, teeth sharp, somewhat rugose; •

valves II to VIII with delicately denticulate jugal plate across sinus, separated from apophyses by small I

notch on each side; girdle scales strongly convex, smooth or striated, in some species with nipple-like

prolongation near the top; gill rows adanal with interspace as in subfamily; major lateral teeth of radula with I

uni- or bicuspid caps as found in some other chiton genera, often with accessory "appendix" tooth near base I

of mineralized cusp.

lm

Subgenus Lepidozona sensu stricto I

Diagnosis. Members of subgenus with single-slitted insertion plates of intermediate valves (unlike I

multi-slitted ones of subgenus Tripoplax Berry, 1919) (genus and subgenus diagnoses based on Van Belle, I

1983; Kaas and Van Belle, 1987).

Lepidozona scabricostata (Carpenter, 1864) I

Figure 3.4

,'|

lschnochiton subexpres_s (Carpenter MS) Palmer, 1945 (nomen n_dum).

Ischnochiton (Lepidozona ) golischi Berry, 1919. l

Lepidozona inefficax Berry, 1963. I

See Ferreira (1978) and Kaas and Van Belle (1987) for more extensive synonymies.

1

Material Examined. The holotype specimen. California: Santa Maria Basin, Phase I Hard-Substrate i

Station BRA 2 (2 juvenile specimens, 120-123 m) and Station BRA 21 (1 specimen, 75-90 m).

Description. Animal maximumally about 24 mm long, but most specimens much smaller; body n

profile elongate oval; valves quite elevated; valves unlike most other members of genus in having a small, It

but distinct, beak; tegmental coloration uniform cream to orange or brown; tegmentum with tiny granules in

quincunx arrangement; radiating rows of pustules number 32-50 on head valve, 3-7 in the raised lateral i

areas of intermediate valves, and about 25 to 40 in the postmucronal region of tail valve; pleural areas with II

many (10-24) fine longitudinal riblets, often ornamented with transversely oval nodules and not conspicuously

latticed in between; jugal region nearly smooth; mucro of tail valve slightly anterior, with slightly concave _l

postmucronal slope; valve slit formula 10-13tltl 1-14; insertion plate teeth sharp, separated by distinct slits; II

eaves solid; articulamentum white; apophyses and jugal laminae quite short in relation to valves; girdle thin

with dorsal side colored like tegmentum and covered with small (100 to 220 flrn wide) closely overlapping •

scales; most scales wider than tall, each with about 15 longitudinal fibs; scales not capped with nipple; gills Ii

adanal with interspace (as in family) and holobranchial, with about 30 gills per side; major lateral teeth of

radula unicuspid with sharp points and no accessory blades. I
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I Figure 3.4. Lepidozona scabricostata, specimen (18 mm length) dredged by fishermen from 340 m on coral, off

Carlsbad, California: A, dorsal view; B, head valve region; C,tail valve region; D, lateral areas of

I intermediatevalves and girdle.

I Remarks. Berry (1925) gave a relatively detailed description of a photographed specimen referred

to as lschnochiton (Lepidozona) golischi Berry, 1919 [= Lepidozona scabricostata (Carpenter, 1864)]. The

holotype and paratype specimens of 1. golischi were from separate collections at about 600 m off Santa

I Monica, cases, were living on the stems of coral, and a specimen

California. In both these the chitons

figured here is from a similar habitat (Figure 3.4, see also Figure 3.5), but there is little indication that L.

scabricostata is restricted to a coral habitat. Collections of coral from the study area, if they exist, have not

I been searched specifically for L scabricostata.

Type Locality and Type Specimens. Catalina Island, California, United States, 18-36 m. Holotype

i (USNM Ha16268) bitat. Reported rarely from intertidal collections. More common from deeper collections down

to 1460 m. Present material includes an adult from 120-123 m (Station BRA 2, 34°1 I'N 120°28'W), and two

I tiny juveniles Dis from 75-90 m (Station BRA 21, 34°47'N 120°46'W). tribution. Lepidozona scabricostata is known from collections as far north as the Gulf of Alaska,

SW of Lituya Bay (57°50.12'N, 136°48.71'W, 119 m), and from as far south as Sebastian Viscaino Bay,

I B93), ajabut California most previous Norte (Ferreira, 1978: 32; Baxter, 1983: 65; Kaas and Van Belle, 1987: 292; Clark, 1991: reports are from relatively deep-water collections off southern California. North of

Point Conception, it has only been reported from Cape Flattery, Washington, Sitka Sound, Alaska, and the

I above-mentioned northernmost locality.

m 65
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Lepidozona retiporosa (Carpenter, 1864) I

Figure 3.5

I

Leptochiton punctatus Whiteaves, 1887. l

Ischnochiton aureotinctus Carpenter in Pilsbry, 1892. m

Ischnochiton venezius Dall, 1919. l

See Ferreira (1978) and Kaas and Van Belle (1987) for more extensive synonymies.

Material Examined. The holotype specimen; also many specimens personally collected. California: I

Santa Mafia Basin, Phase I Hard-Substrate Station BRA 25 (2 specimens, 64.5-72 m), and Phase I SoftSubstrate Station BSS 6 (4 specimens, 109 m).

Description. Animal small, not exceeding 17 mm long, but most specimens much smaller; body l

profile oval; valves only moderately elevated, not beaked; uniform tegmental coloration usually cream but

sometimes tan or apricot, or broad transverse bands of the latter 2 colors; tegmentum with granules of in

uniform size in quincunx arrangement on head valve, lateral areas of intermediate valves, and postmucronal 1

region of tail valve; faint ribs 20-30 on head valve, 3-6 on each lateral area, and 10-15 (very faint) on tail

valve; lateral areas distinctly raised even though ribs rather weak; all these ribs bear rows of very sparse, •

small rounded tubercles, sometimes broken off and generally requiring magnification to observe; central U

areas with longitudinal or diagonally arching rows of shallow pits, separated by slightly higher areas not

forming definite ridges; jugat region occasionally eroded, appearing nearly smooth; mucro of tail valve •

subcentral, postmucronal slope somewhat concave; valve slit formula 8-1311/8-12; regularly spaced insertion II

plate teeth indistinctly slit; eaves solid; articulamentum white; apophyses andjugal laminae short, moderately

wide; girdle thin with dorsal side colored like tegmentum and covered with small (about 145 bun wide) •

closely overlapping rectangular scales, each with about 9 longitudinal ribs; scales not capped with nipple; 1

gills adanal with interspace (as in the family) and holobranchial; major lateral teeth of radula bicuspid with

outer cusp much longer than inner one and without accessory blade. .•

Remarks. This species is most readily recognized by the pitted appearance of its central areas, and I

can be mistaken for a member of Ischnochiton due to the subtleness of its round tubercles. Ferreira (1978)

observed that L. retiporosa can sometimes be collected on the same rocks as L. scabricostata andL. wiIIetti, •

with all three species colored nearly identically (see also Figs 4-10). Little is known about the biology of II

this mostly deeper water chiton.

Type Locality and Type Specimens. Puget Sound, Washington, United States. Holotype (USNM 1 4499).

Habitat. 0-1463 m. Present material consists of two specimens from 64.5-72 m (Station BRA 25,

35°06'N 120°48'W) and four specimens from 109 m (Soft Substrate Station BSS 6, 35°21'N 121°00%V). I

mm

Distribution. This species is commonly dredged in Puget Sound (the type locality) and vicinity

(Eernisse, pers. obs.) and is known to range as far north as Kenai Peninsula, Kachemak Bay, Alaska (R. N. Ill

Clark, pers. comm.), andas far south as the tip of Baja California, Mexico (from Kues, 1974; Ferreira, 1978; I1

Baxter, 1983; Kaas and Van Belle, 1987).

I

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I Figure 3.5. Lepidozona retiporosa, specimen (8 mm length) dredged by fishermen from 340 m on coral, off

Carlsbad, California: A, tail valve region; B,lateral dorsal view.

I

i Subfamily Callistoplacinae Pilsbry, 1893

Callistochiton Carpenter MS, Dall, 1879

I Type Species: CalIistochiton palmulatus Carpenter MS, Dall, 1879, by monotypy.

I heavy radial Diagnosis. ribs onSmall end valves to medium and lateral length, areaselongate-oval of intermediate to elongate; valves; slit tegmentum formula: strongly many/l/many; sculptured incisions with

of insertion plates generally correspond in number and position to radial ribs; teeth sharp, usually thickened

, atrather edgesnarrow; of slits,differs sometimes from peculiarly only other scalloped; genus in subfamily, eaves solid;Ceratozona apophyses Dall, separated; 1882, shell by it'seyes girdle, absent; generally girdle

clothed with scales, sometimes interspersed with spines and spicules, or nude with series of bristle-bearing

i pores; without peculiar corneous spines found in Ceratozona; gill rows adanal with interspace as for other members of this and several other families (based on Van Belle, 1983).

I CaUistochiton palmulatus Carpenter MS, Dall, 1879

Callistochiton paImulatus Carpenter in Pilsbry, 1893 var. mirabilis Pilsbry, 1893.

I Callistochiton acinatus Dall, 1919.

Callistochiton celetus Dall, 1919.

I Callistochiton connellyi Willett, 1937.

See Ferreira (1979a) and Kaas and Van Belle (1994) for more complete synonymies.

I Mafia Material Examined. Specimens from the private collection of G. A. Hanselman. California: Santa Basin, Phase I Hard-Substrate Station BRA 6 (3 specimens, 54-63 m).

I

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Description. Small, up to 16 mm long; oval to elongate oval in shape, becoming increasingly i

elongate, high spired with increasing size; intermediate valve slopes with convex, rounded profile; not

beaked; tegmental color greyish tan to rusty brown; most easily distinguished from other members of Ill

Callistochiton by distinctive fist-shaped bulging tail valve, with anterior mucro and extremely convex I

postmucronal slope (premucronal slope is actually concave); tail valve is considerably elevated relative to

other valves, but less so in smaller specimens; head valve somewhat more than semicircular with a strongly i

convex front slope; valves heavily sculptured, particularly in larger specimens; ribs typically with 9 on head |

valve, 2 on each lateral area of intermediate valves, and about 5 or 6 on tail valve; these ribs extremely

pronounced, pustulose; central areas with about 15 longitudinal latticed riblets per side; riblets in jugal I

region diverge toward anterior margin, forming V-shaped pattern; articulamentum white to light grey; n

apophyses about one quarter length of tegmentum, connected by an unnotched jugal lamina; valve slit

formula 9-11/1/more than 20; slits correspond to ribs on head, but not tail, valve; valve insertion plate teeth m

thick, short, and quite rounded on tail valve; girdle very thin, with dorsal surface colored somewhat more i

deeply than drab valves; dorsal girdle elements small, oval to rectangular, overlapping scales, nearly twice

i

as wide as high, about 130 pm wide, with about 11 longitudinal riblets; gills holobranchial (the distinction

between adanal and abanal difficult to discern in CalIistochiton); major lateral teeth of radula bicuspid, with i

longer outer cusp than inner one.

u

Type Locality and Type Specimens. Santa Barbara, California, United States. Ferreira (1979a), •

designated a neotype, PRM 48. The specimen has been figured by Palmer (1958: fig. 1). i

Habitat. Occurring intertidally to approximately 100 m. Present material consists of three specimens

from 54-63 m (Station BRA 6, 34°30'N 120°36'W). l

Distribution. Continuously distributedbetween Buckhorn Creek,Mendocino Co., California (27° N)

and San Pablo Point, Baja California (39°N0 (from Oldroyd, 1927: 894; Abbott, 1974: 399; Ferreira, 1979a;

Putman, 1982: 365; Kaas and Van Belle, 1994: 170). I

Family Mopaliidae Dall, 1889 "l

Mopalia Gray, 1847

II

Type Species: Chiton hindsii Sowerby in Reeve, 1847, by subsequent designation, Gray, 1847. E

Diagnosis. Small to large size, valves normal in proportion, slit formula: __8111sinus + 2, girdle

slightly dilated at the sides, covered with diverse chitinous productions but lacking scales, gill rows abanal

with interspace as for other genera in this and certain other families.

!

MopMia phorminx Berry, 1919

Figure 3.6 A-D l

Material Examined. The holotype specimen and other lots at SBMNH. California: Santa Mafia

Basin, Phase I Hard-Substrate Station BRA 4 (1 specimen, 168-237 m) and Station BRA 21 (1 juvenile •

specimen, 75-90 m). I

Description. Animal up to 20 mm long, usually smaller; body profile elongate oval; dorsal elevation

moderate; side slopes straight; valves not beaked; tegmentum whitish tan overall, but mottled with yellow i

and brown; tegmental sculpture quite pronounced, with about 8-10 pustular ribs on head valve, interspersed

by 1 or more radiating rows of shorter but distinct pustules; unraised lateral areas of intermediate valves

have 2 ribs similar to those of head valve, again interspersed with 1 or more rows of smaller pustules; I

I
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I relatively small tail valve with one similar, laterally directed rib per side; central areas of intermediate

valves with many well distinguished longitudinal latticed ribs; mucro of tail valve somewhat posterior of

I the girdlemidpo width, int, each withwith moresparse o lesslateral straight branches; postmucronal dorsal surface slope; ofgirdle girdlewithalsolongcovered wispywithbristles, smalllonger calcareous than

blunt spicules, up to 100 pm long; gills abanal with interspace (as for family), gill rows extending about

i two-thirds middle cuspoflongest. length of foot, about 14 gills per side (holotype); major lateral teeth of radula tricuspid with

Remarks. Scott et al. (1990) designated the specimen at SBMNH as lectotype, but there appears

I lit uncommon tle reason species to doubtabout thatwhich the specimen little is known. in question Specimens is the from holotype Alaska(Kaas closely and resemble Van Belle,the1994). presentThis mateisrial. an

Mopalia phorminx (Figures 3.6 A-D) is superficially similar in morphology to M. imporcata (Figures 3.6 El H), with which it cooccurs. Type Locality and Type Specimens. Monterey Bay, California, United States, 62 m. Holotype

(SBMNH 34388).

I Habitat. 18 to 183 m. Present material consists of an adult specimen from 168-237 m (Station

BRA 4, 34°28'N 120°40'W) and a juvenile from 75-90 m (Station BRA 21, 34°47'N 120°46W_r).

i Distribution. There have been sporadic collections of Mopalia phorminx as far north as Naked Island, Prince William Sound, Alaska, and as far south as San Pedro, California (from Abbott, 1974: 403;

Baxter, 1983: 67; Clark, 1991: 94; Kaas and Van Belle, 1994: 259).

I Acknowledgements

I George Hanselman generously provided photographs, including all those used herein not otherwise

credited, as well as many others that were useful in making identifications and key distinctions; Roger Clark

I provided to this study: muchGeorge valuableDavis, consultation. ANSP; James The following McLean, LACMNH; curators provided Terry Gosliner, access to collections CAS; Bob Hershler that wereanduseful M.

G. Harasewych, USNM; and Henry Chancy and Paul Scott, SBMNH. Part of this study was completed

I while the author was Visiting Scientist at the Smithsonian Institution, Laboratory of Molecular Systematics.

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I Literature Cited

I Abbott, R.T. 1974. American Sea Shells, 2nd Ed. Van Nostrand and Reinhold, New York.

Baxter, R. 1983. Mollusks of Alaska. China Poot Bay Society Publications, Homer, Alaska.

I Berry, S.S. 1919. Preliminary notices of some new West American chitons. Lorquinia 2: 44-46.

Berry, S.S. 1925. New or little known southern Californian Lepidozonas. Proceedings of the Malacological

i Society, London 16: 228-231. Buckland-Nicks, J., F.-S. Chia, and R. Coss. 1990. Spermiogenesis in Polyplacophora, with special reference

to acrosome formation. Zoomorphology 109: 179-188.

I Bullock, R.C. 1988. The Genus Chiton in the New World (Polyplacophora: Chitonidae). Veliger, 31: 141-

191.

I Burghardt, G. and L. Burghardt. 1969. A Collector' s Guide to West Coast Chitons. San Francisco Aquarium Society Special Publication 4: 1-45.

i Chelazzi,Operatio G., Della Santina, P. and Parpagnoll, D. 1987.Trail following in the chitonAcanthopleura gemmata:

nal and ecological problems. Marine Biology (Berlin) 95: 539-546.

Clark, R.N. 1982. Chitons of the north-east Pacific. Of Sea and Shore 12: 147-159.

I Clark, R.N. 1983. Systematic classification of the Polyplacophora of the west coast of North America. Of

Sea and Shore 13:11-I2, 15-16, 31.

I Clark, R.N. 1991. Notes on the distribution, taxonomy, and natural history of some north Pacific chitons (Mollusca: Polyplacophora). Veliger 34: 91-96.

i Dell'Angelo, B., J.-S. Hong, and R.A. Van Belle. 1990. The Chiton fauna (Mollusca: Polyplacophora) of

,

Korea, part h suborder Lepidopleurina and Ischnochitonina. Korean Journal of Systematic Zoology

6: 29-56.

I Dethier, M.N. and Duggins, D.O. 1984. An Indirect Commensalism Between Marine Herbivoes and the Importance of Competitive Hierarchies. American Midland Naturalist 124:205-219.

i Duggins,intertidal D.O. andhabitat. Dethier,Oecologia M.N. 1985. (Berlin) Experimental 67: 183-191. studies of herbivory and algal competition in a low

Eernisse, D.J. 1986. The Genus Lepidochitona Gray, 1821 (Mollusca: Polyplacophora) in the northeastern

I Pac 3D52. ific Ocean (Oregonian and Californian Provinces). Zoolische Verhandelingen (Leiden) 228:

i Eemisse, D.J. 1988. Reproductive patterns in six species of Lepidochitona (Mollusca: Polyplacophora) from the Pacific coast of North America. Biological Bulletin 174: 287-302.

!

Figure 3.6. Mopalia phorminx, specimenfrom Gulf of Alaska, 10 mm length: A, dorsal view of specimen; B,

I close-up of tail valve region; C,lateral areas of intermediate valves; D, head valve region. Mopalia imporcata,specimensfrom PortGamble, Washington:E, dorsal view ofspecimen of 11mm length;

F, close-up of tail valve region of 17nun long specimen; G, lateral areas of intermediate valves of

I! same specimen asF; H, headvalve region of same specimen asF.

I 71
!

Eernisse, D. J., In Press. A systematic and biogeographic compilation of Recent chiton species (Mollusca: i

Polyplacophora) utilizing novel mapping software for HyperCard. Miscellaneous Publications of

the Museum of Zoology, University of Michigan. i

Eernisse, D. J., and P. D. Reynolds. 1994. Chapter 3. Polyplacophora. In: F. W. Harrison and A. J. Kohn

(eds.), Microscopic Anatomy of Invertebrates, Volume 5, Mollusca 1. pp. 56-110. Wiley-Liss, New

York. t

Eemisse, D. J., N. B. Terwilliger, and R. C. Terwilliger. 1988. The red foot of a lepidopleurid chiton:

Evidence for tissue hemoglobins. Veliger 30: 244-247. •

l

Ferreira, A.J. 1978. The genus Lepidozona (Mollusca: Polyplacophora) in the temperate eastern Pacific,

Baja California to Alaska, with the description of a new species. Veliger 21: 19-44.

Ferreira, A.J. ] 979a. The genus CalIistochiton Dall, 1879 (Mollusca: Polyplacophora) in the eastern Pacific, B

with the description of a new species. Veliger 21: 444-466.

Ferreira, A.J. 1979b. The family Lepidopleuridae (Mollusca: Polyplacophora) in the eastern Pacific. Veliger B

22: 145-165. U

Ferreira, A.J. 1982. The family Lepidochitonidae Iredale, 1914 (Mollusca: Polyplacophora) in the northeastern •

Pacific. Veliger 25:93-138. II

Haderlie, E.C., and D.P. Abbott. 1980. Polyplacophora: The Chitons. In: R.H. Morris, D.P. Abbott, and E.C.

Haderlie (eds.), Intertidal Invertebrates of California. pp. 412-428. Palo Alto: Stanford University •

Press.

Hodgson, A.N., J.M. Baxter, M.G. Sturrock, and R.T.F. Bernard. 1988. Comparative spermatology of 11 •

species of Polyplacophora (Mollusca) from the suborders Lepidopleurina, Chitonina and

Acanthochitonina. Proceedings of the Royal Society, London [Biology] 111: i-12.

Kaas, P., and Van Belle, R.A. 1980. Catalogue of living chitons. W. Backhuys, Rotterdam. 144 pp. '!

Kaas, P., and Van Belle, R.A. 1985a. Monograph of living chitons, Volume 1. Order Neoloricata:

Lepidopleurina. E.J. Brill, Leiden. In

II Kaas. P., and Van Belle, R.A. 1985b. Monograph of living chitons, Volume 2. Suborder Ischnochitonina

Ischnochitonidae: Schizoplacinae, Callochitoninae and Lepidochitoninae. E.J. Brill, Leiden.

Kaas, P., and Van Belle, R.A. 1987. Monograph of living chitons, Volume 3. Suborder Ischnochitonina B

Ischnochitonidae: Chaetopleurinae, and Ischnochitoninae (pars). Additions to Vols 1 and 2. E.J.

Brill Publishers, Leiden. •

Kaas. P., and Van Belle, R.A. 1990. Monograph of living chitons, Volume 4. Suborder Ischnochitonina:

Ischnochitonidae: Ischnochitoninae (continued). Additions to Vols 1, 2 and 3. E.J. Brill, Leiden. i

Kaas. P., and Van Belle, R.A. 1994. Monograph of living chitons, Volume 5. Suborder Ischnochitonina: g

Ischnochitonidae: Ischnochitoninae (concluded), Callistoplacinae; Mopaliidae; additions to Vols

1-4. E.J. Brill, Leiden. ,•

II Kozloff, E.N., and L.H. Price. 1987. Class Polyplacophora. In: Kozloff, E. N. Marine invertebrates of the

Pacific Northwest. pp. 185-192. University of Washington Press, Seattle.

Kues, B.S. 1974. New occurrences oflschnochiton retiporousCarpenter, 1864, in the eastern Pacific Ocean. i

Veliger, 16: 366.

i
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I McLean, J.H. 1962. Feeding behavior of the chiton Placiphorella. Proceedings of the Malacological Society

of London 35: 23-26.

I McLean, J.H. 1969. Marine shells of southern California. Los Angeles County Museum of Natural History, Science Series 24, Zoology No. 11.

I Mook, D. 1983. Homing in the West Indian chiton Acanthopleura granulata Gmelin, 1791. Veliger 26: 101-105.

Mullineaux, L.S. 1986. Organisms living on manganese nodules and crusts: distribution and abundance at

I three North Pacific sites. Deep-Sea Research 34: 165-184. ,

Oldroyd, T.M. 1927. Chitons. In: Marine Shells of West Coast of North America, Vol. 2. pp 260-263.

I Stanford University Publications, Geolological Sciences. Palmer, K.V.W. 1958. Type specimens of marine Molhisca described by P.P. Carpenter from the west coast

(San Diego to British Columbia). Memoir of the Geological Society of America, 76: i-vii + 1-276,

I pls. 1-35.

Pilsbry. H.A. 1892-94. Monograph of the Polyplacophora. In: G.W. Tryon, Manual of Conchology 14: 1-

128, pls. 1-30 (1892); I-XXXIV, 129-350, pls. 31-68 (1893); 15: 1-64, pls. 1-10 (1893); 65-133,

I pls. 11-17 (1894). Academy of Natural Sciences, Philadelphia.

Putman, B.F. 1982. The littoral and sublittoral Polyplacophora of Diablo Cove and Vicinity, San Luis

I Obispo County, California. Veliger 24: 364-366.

Saito, H., and T. Okutani. 1990. Two new chitons (Mollusca: Polyplacophora) from a hydrothermal vent

I site Malacology of the/heya Small Ridge, Okinawa Trough, East China Sea. Venus the Japanese Journal of 49: 165-179.

Saito, H. and J. Okutani. 1991. Taxonomy of Japanese species of the genera Mopalia and Plaxiphora

I (Polyptacophora: Mopaliidae). Veliger 34:172-194.

Scott, P.H., F.G. Hochberg, and B. Roth. 1990. Catalog of Recent and fossil molluscan types in the Santa

Barbara Museum of Natural History. I. Caudofoveata, Polyplacophora, Bivalvia, Scaphopoda, and

I Cephalopoda. Veliger 33 (Suppl. 1): 1-27.

Sirenko, B.I. and O.A. Scarlato. 1983. Chitons of the North West Pacific region. Conchiglia 15(166-167):

I 3-7.

Skoglund, C. 1989. Additions to the Panamic Province chiton (Polyplacophora) literature - 1971 through

i 1988. Festivus, 21: 78-90. Smith, A.G. 1947. Check-list of west North American marine mollusks: class Amphineura, order

Polyplacophora. Minutes of the Conchotogical Club of southern California 66: 17-19.

I Smith, A.G. 1975. Smaller molluscan groups: Scaphopoda, Cephalopoda, Polyplacophora. In: R.I. Smith

and J.T. Carlton (eds.), Light's Manual: Intertidal invertebrates of the central California Coast. pp.

i 455-466. University of California Press, Berkeley. Thorne, M.J. 1968. Studies on homing in the chitonAcanthozostera gemmata. Australian Journal of Marine

Freshwater Research 19:151-160.

,!:. Van Belle, R.A. 1983. The systematic classification of the chitons (Mollusca: Polyplacophom). Informations

de la Soci6t6 Beige de Malacologie 11: 1-178, pls. 1-13.

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Van Belle, 1985. The systematic classification of the chitons (Mollusca: Polyplacophora). Addenda I (with I

the description of the genus Incisiochiton gen. n.). Informations de la Soci6t6 Belge de Malacologie

13: 49-59. I

Vermeij, G.J., A.R. Palmer, and D.R. Lindberg. 1990. Range limits and dispersal of mollusks in the Aleutian

Islands, Alaska. Veliger 33: 346-354.

War6n, A. 1991. Hanleya nagelfar, a sponge-feeding ecotype of/-/, hanld)i or a distinct species of chiton? I

Ophelia 34: 51-70.

Watters, T.G. 1990. A review of the Recent eastern Pacific Acanthochitoninae (Mollusca: Polyplacophora: _I

Cryptoplacidae) with the description of a new genus, Americhiton. Veliger 33: 241-271.

Wingstrand, K.G. On the anatomy and relationships of Recent Monoplacophora. Galathea Report 16: 7-94. I

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4. CLASSSCAPHOPODA

i by

Ronald L. Shimek 1

I Introduction

i Scaphopods are bilaterally symmetrical mollusks that are enclosed in a tubular curved shell with

openings at both ends. The shell is secreted by the mantle, which surrounds the entire animal enclosing the

I mantle the footcaarevitanterior, y. Althoughthe narrow the deriapex ved anatomical posterior, the orientation concave issidediffere dorsal, nt, function and the aconvex lly the side largeventral. apertureThese and

functional orientations are used in the text.

I of the prWithin oboscistheormbuccal antle capouch vity, theon feeding the reduced tentacles head.orThe captacula foot extends originatefromfromthefolanterior ds lateralaperture to the base for

burrowing (Lacaze-Duthiers, 1856-57; Morton, 1959; Fisher-Piette and Franc, 1968) and the captacula

I e1988) merge(Figure from the4.1). same aperture during feeding (Morton 1959, Dinamani 1964a, 1964b; Poon, 1987; Shimek,

I

CG

i BP " t R

I ."_::""=V_'r_'=-<':_y_" ..... ".-._-:":.:_:_""

I

I

A

i Figure 4.1, Semi-diagrammatic illustration of a dentaliid scaphopod with the shell removed, and the mantle reflected as if cut with a scalpel. Major organs and structures are labelled. A = Anus; BP = Buccal

Pouch; C = Captacula; CG = Cerebral Ganglia; DG = Digestive Gland; F = Foot; G = Gonad; N =

i Nephridium; R = Radula; RR = Respiratory Ridges.

I _ILS.E.I.,P.O.Box4,Wilsall,Montana59086-0004,USAandDepartmenotfBiology,MontanaSlateUniversity,Bozeman,

d Montana59717

i 75
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The visceral mass extends to the shell apex and is not coiled or folded. The radula is relatively i

massive and heavily mineralized (Morton, 1959; Vouvelle and Grasset, 1983; Shimek, 1990). The mouth is

located terminally on a short buccal pouch, or proboscis, inside the mantle cavity. The short esophagus II

extends to a relatively large stomach opening into one or two digestive glands. The coiled intestine leads to |

the anus near the middle of the body (Lacaze-Duthiers, 1856-57; Morton, 1959; Taib, 1981a).

No eyes, osphradia, or ctenidia are found. The mantle has numerous sensory cells and some discrete •

sense organs (Steiner, 1990). The nervous system resembles that of bivalves, but is more elaborate. While II

the open circulatory system is relatively large, the heart consists of only a single ventricle (Steiner, 1990).

Excretory organs are present, but the renopericardial connection to them is unclear (Reynolds, 1990). The i

sexes are separate (Wada, 1968). l

One or two pairs of dorsal retractor muscles attach subapically to the shell and give rise to the

pallial and pedal musculature. The pedal and retractor musculature and the relative hemocoelic volumes are i

different in the two orders, and the action of the foot is correspondingly different. In the Order Dentaliida,

the foot is extendable and functions as a muscular hydrostat, while in the Order Gadilida the foot is

introvertable and hydraulic (Figure 4.2 A-B). i

The gross anatomy of scaphopods is relatively well known. The early investigations of

Lacaze-Duthiers (1856-57) on the anatomy and embryology of Antalis (= Dentalium) dentalis are the basis

for all subsequent work. A substantial body of work from the late nineteenth century elaborated on the work !

of Lacaze-Duthiers and lead to the basic understanding of scaphopod morphology (Fol, 1889; Pelseneer, ll

1891; Plate, 1892; Leon, 1894; Boissevain, 1904). Simroth (1894a, b), erected the Class Scaphopoda. ii

i

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_ _. _ _-..._. _l_ .". • . • _ :

i

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Figure 4.2. Generalized Scaphopods. A. Dentaliid scaphopod with the foot extended and the epipodial lobes

extended;B. Gadilid scaphopodwith the foot extended, note the foot's terminal disc. i

I
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I More recent investigations have focused on the cellular and fine structure of individual tissues,

organs, and organ-systems within individual taxa (Gabe, 1949; Gabe and Prenant, 1950a, b; Arvy and Gabe,

i 1951; Sahlmann, 1973; Taib, 1976, 1981a, b; Reynolds, 1988, 1990; Steiner, 1990, 1992; Shimek and Steiner, in preparation). Recently, Steiner (1990) has completed comparative ultrastructural and morphological

investigations across the entire Class Scaphopoda. This work will undoubtedly lead to a more thorough

understanding of scaphopod functional morphology (Shimek and Steiner, in press) and will likely result in

I a systematic revision of the Class.

Scaphopod gametes have been extensively used in developmental research since the early part of

I the Dufresne-Dube twentieth century, et al (Wilson, 1904; Van Dongen and Geilenkirchen, 1974a, 1974b, 1974c, 1975; . (1983). However, except for one or two species of dentalids, little is known about the

larval development of scaphopods.

I have beenScaphopods described,areofentirely which, marine, about 25andhavelivebeen in unconsolidated described fromsediments. the west About coast of300North extantAme species rica.

Scaphopods are found from the low intertidal to abyssal depths (Knudsen, 1964) and, while very common in

I some (Scarabino, shallow1979). water communities, (Shimek, 1989, 1990), they are more diverse in deeper waters (<-500m)

Although dentaliid scaphopods have been known to eat foraminiferans and other small shelled prey

I (Mor 1972;ton, Bilyard, 1959; Dinamani, 1974). The 1964a, b), quantitative data on feeding has only recently been obtained (Gainey, first account of the feeding behavior of any gadilid was published by Poon

(1987). Shimek (1988) provided additional quantitative data on gadilid and dentaliid feeding. Shimek's

i (1990) detailed analysis of comparative dietary and habitat resource utilization of several sympatric scaphopod species provided the first evidence of the ecological role of these predators.

Scaphopod systematics is in a state of flux. The comprehensive conchological and systematic treatI ments by Pilsbry and Sharp (1897-98) and Henderson (1920) have been the basis for all subsequent work. In

a series of papers, Emerson (1951, 1952, 1962) revised and clarified basic scaphopod systematics.

Starobogatov (1974) and Palmer (1974) separately elevated the families Dentaliidae and Siphonodentaliidae

I (now Gadilida) to ordinal rank. Kraeuter (1971), Chistikov (1975), Emerson (1978), and Scarabino (1979)

are other important contributors to scaphopod classification on the generic and family level. Steiner (1990,

1992) has clarified many of the differences between the two orders, and further substantial revisions to the

i class will likely result.

i Glossary

Apertural tube. A thin cylindrical tube produced Digestive or midgut glands (=glandular

I as a secondary shell by the mantle of the pouches from the molluscan stomach). Site dorsal or apical aperature in scaphopods, of most digestion. In the scaphopod order

Dentaliida there are two glands (one on each

Buccal pouch. Lateral pouches or extensions of side) in the order Gadilida, only one gland, the buccal tube or proboscis in scaphopods; on the left side, is found.

used to store captured prey prior to

i C maceration. Mantle. Specialized epithelial and epidermal layer aptaculum (plural = eaptaeula). Scaphopod in the Mollusca that secretes the shell.

sensory and food capturing tentacles Mantle cavity. In molluscs, this cavity is formed

cobulbnsiswith ting aofcentral a slender pit orstalkalveolus. and a termi Captacula nal inmouth, ternal excretory to the manaperatures, tle and contains gonadalthe

adhere to a food item and pull it into the aperatures, as well as the respiratory

mantle cavity.
I

structures. In scaphopods, the mantle cavity Proboscis. In scaphopods, the cylindrical tube I

is tubular and open at both ends. formed from the tissue posterior to the lips

to the bulbous region of the radula; also []

Obsolete. A term used to describe shell sculpture known as the bueeal tube, it generally

in molluscs, meaning that the sculpture contains the buccal pouches used to store

becomes indistinguishable form the

background ornamentation. PreY"

Radula. The molluscan trituration or rasping

Osphradia. Molluscan chemosensory organ; structure. Formed in a ventral diverticulum

lacking in scaphopods, of the foregut, it consists of secreted teeth i

Pallial musculature. Musculature of the mantle in on a basal ribbon. In scaphopods, it is II

molluscs, relatively large and highly mineralized with

calcium and iron salts.

Pedal musculature. Musculature of the foot in !

molluscs. In the scaphopod Order Renoperieardial connection. The typical

Dentaliida, this musculature is continued molluscan connection between the exretory

into the body wall musculature, while in the tissue and the pericardium.

Order Gadilida, this musculature continues

Retractor musculature. In molluscs, the

as the dorsal retractor muscles.

musculature connecting the foot to the shell. II

Contraction of this musculature pulls the I!

foot into the shell.

!

!

Systematic Treatment for the Santa Maria Basin Area

(FollowingSteiner, 1990) i

Class Scaphopoda Bronn, 1862 i

Order Dentaliida DaCosta, 1776 Order Gadilida Starobogatov, 1977 !

Family Dentaliidae Gray, 1834 Family Gadilidae Stoliczka, 1868

Antalis H. and A. Adams, 1854 Gadila Gray, 1847 m

Dentalium Linnaeus, 1758 Siphonodentalium M. Sars, 1859 i

Fissidentalium Fischer, 1885 CaduIus Philippi, 1844

Family Rhabdidae Chistikov, 1975 Family Pulsellidae Scarabino, 1982 I

Rhabdus Pitsbry and Sharp, 1897 Pulsellum Stoliczka, 1868

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78 I 
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I Taxa Treated in This Atlas

I

Species Examined from the MMS Santa Maria Collections

I Dentalium vallicolens Raymond, 1904 Rhabdus rectius (Carpenter 1864)

Cadulus tolmiei DaI1, 1897

I Gadila aberrans (Whiteaves 1887)

Siphonodentalium quadrifissatum (Pilsbry and Sharp 1898).

!

Additional Species Likely to be Encountered in the Study Area

I Antalis Dentaliumpretiosum neohexogonum (Sowerby 1860) (PiIsbry and Sharp 1897)

Fissidentalium megathyris (Dall, 1890)

I Fissidentalium erosum Shimek and Morens, 1996

Cadulus californicus (Pilsbry and Sharp 1898)

t GadiIa perpusillus (Sowerby, 1832) PulseIlum salishorum Marshall, 1980

I

i Key to the Scaphopods of the Santa Maria Basin

1A. Shell length commonly exceeding 2 cm; median radular tooth twice as wide as long; foot extendable

t lB. with Shell mlength ore-orc-less ommonly conicallesstipthan ........................................................................................................... 2 cm; median tooth of radula nearly as long as wide, may be very2

small compared to other teeth; foot an introvert with expandable disklike tip ............................... 8

I 2A. Shell without longitudinal or linear sculpture; annular sculpturing or lines may be present ......... 3

i 2B. Shell has longitudinal or linear sculpture, at least near narrow, apical, end of shell; surface of shell sometimes severly eroded, but sculpture found in uneroded areas ................................................. 5

I 3A. Shell robust, thick, white, without longitudinal or linear sculpture, but with obvious annular markings; if apical end intact, narrow slit may be present ..................................................... Antalis pretiosum

3B. Shell thin, often fragile, white to tan, often showing healed fractures or evidence of surface erosion. 4

!

4A. Shell nearly straight, white; very fragile, unereded shell smooth, not glossy; juvenile shell smooth

i 4B. withou Shell nearly t sculpture ..................................................................................................... Rhabdus rectius straight, beige to tan; uneroded shell glossy; if juvenile shell present, with longitudinal

striations or ridges .......................................................................................... Dentalium valIicolens

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5A. Longitudinal shell sculpture with 6 major ribs or ridges, and often many smaller secondary ribs I

continuing to anterior aperture; although ribs may appear rounded or blunt at aperture; shell white

................................................................................................................. DentaIium neohexogonum Ig

5B. Longitudinal shell sculpture consists of 7 or more major ribs ........................................................ 6 1

n

6A. Longitudinal shell sculpture with 7 or more major ribs or ridges starting at apical end and continuing •

anteriorly only short distance; anteriorly ribs become less distinct and fine striae or lines appear

between them; f'me striae may continue to anterior aperture but may require magnification to be IN

observed; shell long and narrow, somewhat fragile; shell nearly straight, beige to tan; uneroded II

shell glossy ..................................................................................................... Dentalium vallicolens

6B. Longitudinal shell sculpture with numerous incised ribs running length of shell; shell robust and Ill

large, often more than 6 cm long; ventral aperture 1 cm in diameter. Found in deep water, generally 1

in excess of 500 m.......................................................................................................................... 7

7a Total length of preserved, unrelaxed soft parts more than one-half total shell length; surface of shell I

n

with little erosion, ventral aperture round, shell white, but may have brownish adherent periostracum

or organic layer ........................................................................................ Fissidentalium megathyris I

II

7b Total length of preserved, unrelaxed soft parts less than one-half total shell length; surface of shetl

with considerable erosion, particularly near posterior (apical end), ventral aperture wider than high,

shell white, but may have blackish adherent periostracum or organic layer .................................... _l

....................................................................................................................... FissidentaIium erosum !1

8A. Shell widest at aperture ................................................................................................................... 9 I

8B. Shell widest posterior to aperture .................................................................................................. 12

I

9A. Apex of shell with 4 small slits and lobes; shell white although ovary may be pink in mature animals

..................................................................................................... Siphonodentalium quadrifissatum tim

9B. Apex of shell without 4 small slits and lobes ................................................................................ 10 I

10A. Shell smooth or eroded, but not polished or glossy ....................................... PuIsellum salishorum I

I

10B. Shell glossy, highly polished ......................................................................................................... 11

11A. Shell obviously wider (more than 1.75 times as wide) at aperture than in middle third of shell ..... I

....................................................................................................................... Juvenile Cadulus spp.

1lB. Shell only slightly (less than 1.5 times as wide) wider at aperture than in middle of shell .............. Im

.......................................................................................................................... Juvenile Gadila spp.

m

12A. Widest point in middle third of shell; shell either decidedly swollen or not noticeably enlarged .... !

....................................................................................................................................................... 3

12B. Widest point in anterior third of shell; shell only slightly wider posterior to aperture than at aperture, I

not noticeably swollen, maximum width generally about one sixth or less total length; length generally ll

less than 1 cm ................................................................................................................................ 15

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I 13A. Shell swollen, widest part of shell very evident, maximum width about one fifth or more of total

length; apex of shell may have lobes; ovary brown; length often more than 1 cm ...................... 14

I 13B. shell Shel length; slender,apex widest of part shellonly withslightly 4 smallwider slits than and lobes, aperture; shellmaximum white although width less ovarythanmayonebef'ffthpinktotalin

mature animals ............................................................................ Siphonodentalium quadrifissatum

i 14A. Shell robust, white, opaque; without lobes around apical aperture ...................................................

.......................................................................................................................... Cadulus californicus

I 14B. Shell thin, hyaline, transparent or translucent in living animals; with 0-7 lobes around apical aperture

.................................................................................................................................. Cadulus tolmiei

15A. Shell narrows sharply to aperture; aperature can appear constricted ................................................

............................................................................................................................. Gadila perpusillus

I 15B. Shell narrows gradually to aperture and only slightly narrower than widest point of shell .............

................................................................................................................................. Gadila aberrans

Descriptions of Species

I For the descriptions, a typological descriptive approach was used and supplemented by a quantitative shell morphometric analyses that was based on the mathematical properties of shell shape (Raup

i 1964). The morphomelric analyses ideally require "perfect" undamaged shells. Such shells are rare, and to increase statistical reliability, it was necessary to examine and measure shells with minor fractures, apertural

- lip breaks, and apical fractures. I tried to be as conservative in the use of these shells as possible, but their

i use undoubtedly increases variance into the analyses. In each description, the heading "Material Examined" refers only to those shells actually measured. For each species, numerous other individuals were actually

examined. Three morphometric indices were used for the majority of the descriptions, for detailed derivations

I of the indices and measurements, see Shimek (1989). The three principal morphometric indices are:

atan(__(_c. ) )

LTot Lrot-_

Whorl Expansion Rate: Ws =

I 4(LTot -- Larc) 2 + (arc) 2

!

ln(ApW + 1)

i Width Index: W/ = ln(Wmax + 1)

I ln(LWmax + 1) Length Index: L/ = In(LTot)

I
!

Where: Ltot = Total Length U

LWmax = Length from anterior aperture to the maximum shell width

Wmax = Maximum shell width I

g

ApW = Aperture width

arc = Maximum perpendicular distance from the chord connecting the dorsal margin

of the posterior aperture to the dorsal margin of the ventral aperture. il

Larc = Distance from the apex to the point were "arc" is measured.

The mean and standard deviations of the indices or measurements were computed, with the exception i

of Ws, the whorl expansion rate. The whorl expansion rate is a logarithmic function and calculations of this n

index are sensitive to small changes of shape. I used the mean of the natural logarithm of this index for

comparative purposes. The mean of a logarithmically transformed numerical array is the median of the i

untransformed array. The median is a better indicator of the central tendency of that array than is the mean tN

as it is less sensitive to extreme values (Sokat and Rohif, 1981). The mean Ws is also given for comparative

purposes. The morphometric indices were compared between and within populations to assess variance, by n

the use of standard statistical graphics software (STSC, 1986-91). Any significant differences were noted in IN

the discussions.

II

Order Dentaliida DaCosta, 1834 i

Family Rhabdidae Chistikov, 1975 _1

Genus Rhabdus Pilbury and Sharp, 1897 li

Type Species: Dentalium rectius Carpenter, 1864. i"

Diagnosis. Shell almost perfectly straight, very slender, regularly tapering toward apex, thin, and I_

very fragile, translucent and almost colorless except where heightened by erosion. Sculpture none, with il

growth-striae being nearly or quite invisible except where slight surface erosion has traced them. Aperature

hardly oblique, circular. Anal orifice circular, but apparently without true slit or notch. 1

m

Rhabdus reetius (Carpenter, 1864)

Figure 4.3 n

Dentalium rectius Carpenter, 1864:603,648.-- Pilsbry and Sharp, 1897:113-114.----Grant and Gale, 1931:437. Inn

Dentalium daUi Pilsbry and Sharp 1897:114-115. N

Dentalium watsoni Pilsbry and Sharp 1897:113.

Material Examined. California, Santa Mafia Basin, Sta. 61 (5); Sta. R-2 (4); Sta. PJ-9 (2).-- I

British Columbia, Barkley Sound, Vancouver Island, specimens from 4 localities: Mayne Bay, 35-40 m,

Imperial Channel, 75-80 m, Trevor Channel, 30-110 m, Sarita Bay, 150-350 m (483) (Shimek, 1989). n

II Description. Shell slender, tapering, fragile, slightly curved; but adult shells appearing straight;

shell translucent to transparent in juveniles, relatively opaque in adults (shell length 30 mm). Shell chalky,

not polished; ventral (= oral or anterior) aperture round, perpendicular to longitudinal axis of shell; annular tR

growth lines prominent; dorsal aperture often showing signs of healed fractures and decollation (Reynolds, II

1992), and sometimes with secondary apertural tube. Adult size indeterminate; specimens with total length

over 75 mm uncommon, specimens over 130 mm rare (Figure 4.3). N

|
!

I

.. " ":"-

m • " .'_ " I ° °

I cm

!

I Figure 4.3. Rhabdus rectius (Carpenter, 1864).

Shell Morphometric Indices (Shimek, 1989). Shell maximum width/length to shell ratio = 0.072

_+0.39,ln(Ws) = 14.86 _+7.00 (Ws = 2.8 x 106); WI = 1, and LI = 0, as aperture is widest portion of shell.

i Santa 11.09 Maria (Ws =Bwhorl asin Specimens: expansion rShell ate = maximum 1.6 x 102°);width WI /=length 1, and toLIshell = 0,ratio as aperture = 0.070widest _+0.07,portion ln(Ws)of=shell. 17.10 -!-_

Externally Visible Soft-part Morphology. Mantle dull milky-white; radula dark; digestive gland

I functionally dorsolateral folds, dorsal.with Mantle foot aextending circular opening through when opening. extended Mantlefromsometimes ventral aperture. protrudingMantle severaloftenmillimeters forming

beyond dorsal aperture in adult (shell length > 10 mm). No consistent sexual differences in shape of"pavillon,"

I or adults, tube dentaliform, formed from with the dorsal centralmantle projection edge, and visible epipodial in livinglobes; animals. lateralFoot margins extendable of epipodial for aboutlobes 5-10smooth. mm in

Captacula numerous, several hundred in adults, extendable to 5+ mm; terminal bulb densely ciliated, stalk

i arranged in linear band (visible with magnification) (Shimek, 1988). Visible Internal Morphology. In juveniles with thin shells, radula visible through shell, brownish to

black, highly mineralized. Cerebral ganglia visible through shell ventral (= anterior) to radular mass, pinkish.

Inapparent: adult animals digestivewithglandthicker dark shells, brown above to black,features prominent, may not visiblebe visible, through but the following shell; gonadsfeatures visiblegenerally through

adult shells, brilliant white in males, yellow (ova) in females (Hebert, 1986).

I Internal Morphological Characters. Radula large for size of animal; radular formula 1-1-1-1-1;

marginal teeth large, platelike; lateral teeth rounded, with cusps, central tooth large; all teeth mineralized

with iron and calcium salts.

i

B Biology. Rhabdus rectius eats a wide variety of food items including sediment, fecal pellets,

kinorhynchs, and various invertebrate eggs, however, foraminiferans are the most numerous prey. Rhabdus

i rectius is a sediment generalist, however, it is most abundant in silty areas with more than about 5% organic

material by weight. In British Columbia, the species ranged in abundance from about 5 animals per m2in

clean sand, to about 66 animals per m2in silt. Foraminiferans were rare where it was most abundant.

i • Typ Distriebut Locioality n. Peru and toTyAlaska; pe SpecCook imens.Inlet Holotype (PilsbryUSNM and Sharp (5283); 1897-98; Puget Keen Sound,1971; Washington. Baxter 1987).

I

!

• I 83
!

Family Dentaliidae Gray, 1834 I

Genus Antalis H. and A. Adams, 1854

Type Species: Dentalium entalis Linnaeus, 1758. !

Diagnosis. Shell circular or polygonal in section, with longitudinal ribs or striae atleast in juveniles, in

although these sometimes lacking in adults, or found only near the apex; apex generally with V-shaped •

notch at or near convex side, sometimes with solid plug and central short tube or orifice. Foot with epipodial

sheath. Shell greatest in diameter at anterior (= ventral) aperature. /

Remarks. No species of Antalis were encountered in the Santa Mafia Basin collections. However, l

it is likely that A. pretiosum is present. See the key for differential characters.

all

Genus DentaIium Linnaeus, 1758 I

Type Species: Dentalium elephaninum Linnaeus, 1758.

II Diagnosis. Shell prismatic, generally with distinct ribs; ribs often strongly developed toward apex,

with 4-14, sometimes as many as 20. Apex with no notch or slit, or short one. Foot with epipodial sheath.

Shell greatest in diameter at anterior aperature. I

Dentalium vallicolens Raymond, 1904 I

i

Figure 4.4

Dentalium vallicolens Raymond, 1904:123-124.--Keen, 1971:883.--Abbot 1974:386. I

Material Examined. California, Santa Mafia Basin, Sta. 61 (2); Sta. 86 (1); Sta. R-6 (2); syntype

collection from off Santa Monica Bay, 290 m, off Point Fermin, 200 m, and La Jolla Canyon, off San Diego, •

128 m: (CAS, 064383) (1); (CAS, 064385) (1): (CAS, 066519) (4); off Los Angeles and Orange County, I

128-164 m, (LACMNH, 41-7.1) (2), 62-150 m, (LACMNH, 40-116.3) (1), 128-164 m, (LACMNH, 39-

100.3) (2), off San Diego, 124 m, CAS (075694) (1); 198-430 m, (CAS, 075698) (1); 164-184 m, (CAS,

075699) (1); (CAS, 075700), (1).--Mexico, off Guadelupe Island, Melpomene Cove, 20-36 m, Baja N

California, Cabo San Lucas, 24 m, (CAS, 075695) (3); Mexico, 117-119 m, (LACMNH 41-33.2) (7).

Description. Undamaged adult shell smooth, relatively polished, sometimes with many healed I

i

fractures; most shells chalky due to erosion; shells white in juveniles, tending to tan or beige in adults. As l

typical for dentaliids, younger specimens proportionally more slender and strongly curved than adults; shell

laid down after sculpture becomes obsolete almost straight. Dorsal (apical) aperture of juvenile specimens 1

surrounded by 6-17 strong ribs; these becoming obsolete as animal grows; first, finer riblets occurring lip

between them, after which they decrease in height. Finally at about 20-30 mm total shell length, or at about

an aperture width of 3 mm, shell appearing smooth without magnification; fme longitudinal lines or striae 1

visible with magnification. Annular sculpturing variable, from weak to absent: generally as fine lines RI

visible under 10x magnification; complete growth rings rare; aperture circular (Figre 4.4).

Shell Morphometric Indices. For all specimens, shell maximum width/length to shell ratio = 0.116 i_I

___0.073, In(Ws) = 6.05 ___2.84 (Ws = 6.12 x 104); WI = 1 and LI = 0 as aperture widest portion of shell).

Adults defined as those animals with aperture width of 3 mm or greater; these animals exhibiting relatively

smooth shell form of the adult. Specimens with adult morphology varying in total length from 14.2 to 65.0 •

mm; aperture = maximum width 3.0 to 7.0 mm; smaller specimens more strongly curved; whorl expansion m

rates range from about 10 for smaller individuals to about 1.5 x 106for largest; adult shell maximum width/ 1

length to shell ratio = 0.12 _ 0.09, lrt(Ws) = 6.60 _ 2.99 (Ws = 9.06 x 104). '1

84 I
!

I

7 cm

| ',

I ,._ ....._.

i I.;_...,-.'.:,...'; L, ". .'" ,- -- . .. .... -: ":"[ ",'"_-%'-

|

| B :

II

i Figure 4,4. Dentaliu fibs. C. Dorsal m vaUshell icolens apex, Rayapical mondview 1904.showing A. Entirelongitudinal shell. B. Dorsal fib. shell apex showing longitudinal

I Internal morphology not known.

Biology. tn the Santa Maria Basin, DentaIium vallicolens occurred in sediments having high silt

i inventories. Several of the museum specimens exhibited evidence of drilling by naticids. Many specimens show healed fractures indicating decollation or unsuccessful attempted predation, possibly by crabs or fish.

The raffish, Hydrolagus coUiei, preys on Rhabdus rectius in British Columbia, perhaps similar predation

g occurs here Type(Shimek, Locality1990). and Type Speeimens California: Santa Monica Bay, 290 m, off Point Fermin, 200

m, from La Jolla Canyon offSan Diego, 128 m.

g limit of Di thisstribspecie utions.is Strai doubttsfulof and JuanindeneFeducaoftoveGulf rification. of California (Keen 1971), but the published northern

I Fissidentalium Fischer,

Genus 1885

Type Species: Dentalium ergasticum Fischer, 1885.

Diagnosis. Shell large and solid, sculptured with many longitudinal riblets; apex typically with long slit, but often simple, sometimes with slit divided by series of fissures. Foot with epipodial sheath.

Shell with greatest diameter at anterior aperature.

I Remarks. No specimens of Fissidentalium were encountered in the Santa Maria Basin collections. However, it is likely that F. megathyris and F. erosum might be eventually encountered. See the key for

differential characters.

!

.
!

Order Gadilida Starobogatov, 1977 I

Family Gadilidae Stoliczka, 1868 j

III

Genus Cadulus Philippi, 1844

Type Species: Dentalium ovulum Phillipi, 1844. I

u

Diagnosis. Tubular, circular or oval in section; somewhat arcuate; more-or-less bulging or swollen

near middle, constricted toward anterior aperature. Shell smooth or delicately striated. Anterior aperature t_

constricted, widest portion of shell posterior to aperature. Foot expanded into terminal disk with fringing !I

tentacles.

i

Cadulus tolmiei Dall, 1897 J

Figure 4.5 i

Cadulus toImiei Dall, 1897:13, pl 1.--Pilsbry and Sharp, 1898:181-182.

i

Material Examined. California, Santa Maria Basin, Sta. 50 (2); Sta. R91 (2).--British Columbia, 1

W. coast Vancouver Island, Barkley Sound, Sarita Bay, 150-350 m, (16) (Shimek ]989).--Types: Cadulus

toImiei USNM (107613); Cadulus caIifornicus Pilsbry and Sharp, 1897, USNM (107698).

Description. Adult shell thin, translucent, polished, slightly bluish-white, internal organs easily |

visible through shell. Shell widest in anterior third, decidedly curved (Figure 4.5). Ventral or anterior aperture

oblique, circular. Apical (dorsal) aperture typically surrounded by lobes, but these variable in number from J

2 to 7, and fissures between them varying in prominence (Shimek 1989). Juveniles easily distinguished |

from adults, with widest part of shell at aperture. Growth probably determinate, with little growth occurring

after aperture narrows, i

Shell Morphometric lndices. Shell maximum width/shell length = 0.22 _ 0.02, ln(Ws) = 5.49 _ 1.00 II

(Ws = 376); WI = 0.71 _ 0.19, and LI = 0.56 _ 0.06. Mean adult total shell length 9.98 __.1.03mm, range

from 7.40 to 12.15 mm. Mean maximum shell width was 2.17 _ 0.17 mm. a

III Externally Visible Soft-part Morphology. Mantle generally dull white. Mantle with triradiate fold,

when extended from ventral aperture; foot extending through center of this triradiate area. Mantle may

protrude about 1 mm beyond dorsal aperture in an adult (shell length > 10 mm). Foot extendable to length I

of shell, caduliform, with terminal disk, papillate laterally. Captacula numerous, over 200 in adults, extendable I

to 2-3 mm; terminal bulb densely ciliated, stalk cilia limited to tufts arranged linearly (visible with

magnification) (Poon, 1987; Shimek, 1988). IWE

Visible Internal Morphology. Radula visible through shell, brownish, highly mineralized; most

highly mineralized areas appearing black. Cerebral ganglia visible through shell ventral (= anterior) to

radutar mass, pinkish. Digestive gland dark brown or black to violet, prominent, visible through shell, i_

Gonads visible through adult shells, brilliant white in males, brown (ova) in females. II

Internal Morphological Characters. Radula large for size of animal; radular formula 1-1-1-1-1; I

marginal teeth large, platelike; lateral teeth hooked, central tooth small; all teeth mineralized with iron and I

calcium salts.

Biology. Santa Mafia Basin specimens of Cadulus tolmiei occur in sediments with high sand and Iii

sand/silt. British Columbia specimens are found in silty sand; foraminiferans are common in this habitat; II

depth distribution 50-400 m. This species is a predator on small foraminiferans, particularly Uvigerina spp.

Prey are maintained in the buccal pouch (= proboscis) prior to trituration (Poon, 1987).

I!i

86 I
!

I

_4h_- .:....i...,....:• ..... •. ..,..._._,-,_

i I cm

! I

I

i Figure 4.5. CadutustotmieiDall, 1897.

I Remarks. CadMus tolmiei is distinguished from C. californicus by the possession of a thinner,

more translucent, shell, and the relatively less inflated region around the widest portion of the shell (Pilsbry

I • and SharpType1897Locali -1898). ty and Type Specimens. Near Vancouver Island, (USNM, 107613).

Distribution. CadMus tolmiei ranges from Baja California through the Eastern Bering Sea (Abbott

I 1974; Baxter 1987).

Genus Gadila Gray, 1847

I Type Species: Dentalium gadus Montagu, 1829.

I Diagnosis. Shell decidedly curved, with general contour anteriorly convex, but concave dorsally; slightly swollen near middle or toward aperature, tapering toward apex; apical orifice not constricted by

callus ring, or with callus far within and weak; edges not slit. Anterior aperature constricted in adults, with

i widest portion of shell posterior to aperature; aperature either not constricted in juveniles or only slightly constricted. Foot expands into terminal disk with fringing tentacles; may have one or more central filaments

or tentacles.

!

!

I

!

!
!

Gadila aberrans (Whiteaves, 1887) "1

Figure 4.6

II

Cadulus aberrans Whiteaves, 1887:124, fig. 2.---Shimek, 1989 (synonymy). J

Cadulus hepburni DalI, 1897:12, pl. 1, fig 13. an

Cadulusfusiformis Pilsbry and Sharp, 1898:193, pl. 35, fig. 14.--Grant and Gale, 1931:493. (synonymy). I

Cadulus nitentiorArnold, 1903:187, pl. 8, fig. 13.

db

Material Examined. California, Santa Maria Basin, Sta. 21 (6); Sta. R-8 (2).---Off Central California, I

36 m, (LACMNH, 60-23), (81); Off Los Angeles, 82 m, (LACMNH, 70-115) (2); 14 m, LACMNH (65-1)

(6); OffSan Diego, 25 m, LACMNH (122873) (6); Mexico, 31-46 m, LACMNH (71-158) (39); Off British •

Columbia, 274 m, (LACMNH, 72-140) (9).--Additional 61 specimens from the Institute of Ocean Sciences, IN

Canada (listed in Shimek, 1989).--Vancouver Island, Barkley Sound (233) (R. Shimek research specimens,

listed in Shimek, 1989). /

Description. Shell slender, slightly curved, highly polished, lustrous, translucent white; minute m

growth lines present (visible with magnification only); ventral (= oral or anterior) aperture oblique, round;

dorsal (= anal, or posterior) aperture rounded, not lobed. No dorsal secondary apertural tube (such as found

in Rhabdus rectius). Shell lip thin and sharp. Juvenile specimens, to about 10 mm in total length, without II

constriction of ventral aperture; adult size determinate, total length to about 13 mm; with slightly constricted

aperture (Figure. 6). I

Shell Morphometric Indices. All adult specimens (Shimek, 1989, and the Santa Maria Basin 41

specimens): Shell maximum width/shell length = 0.13 __.0.02, ln(Ws) = 6.07 _+1.23; (Ws = 1335); WI = 0.85

_+0.06, and LI = 0.51 _ 0.07. Santa Maria Basin adult specimens: shell maximum width/shell length = 0.14

_ 0.01, ln(Ws) = 6.67 __1.33 (Ws = 2316); WI = 0.83 _+0.06, LI = 0.38 _+0.04. m)

Externally Visible Soft-part Morphology. Mantle generally dull white, except for golden ring at

area of outer mantle fold; when extended from ventral aperture, mantle with triradiate fold. Foot extending i

through center of triradiate area. Mantle sometimes protruding about 1 mm beyond dorsal aperture in adult Ju

(shell length > 10 mm). No consistent sexual differences in shape of the "pavilion," or tube formed from

dorsal mantle edge in living animals (Scarabino, 1979; McFadien-Carter, 1983). Foot extendable to length i

of shell, caduliform, with terminal disk, papillate laterally, sometimes with 1 or 2 small papillae visible on Ul

distal face of terminal disk. Captacula numerous, over 100 in adults, extendable to 2 to 3 mm; terminal bulb

densely ciliated, stalk cilia limited to tufts arranged linearly (visible with magnification) (Shimek, I988). I

lm

Visible Internal Morphology. Radula visible through shell, brownish, highly mineralized, most

highly mineralized areas black; cerebral ganglia visible through shell ventral (= anterior) to radular mass,

pinkish. Digestive gland dark brown to black, prominent, visible through shell. Gonads visible through i

adult shells; males, brilliant white; females with ova brown, occasionally pink (Hebert, 1986).

m

Internal Morphological Characters. Radula large for size of animal; radular formula 1-1-1-1-1; a

marginal teeth large, platelike; lateral teeth hooked, with 2 cusps, central tooth small; teeth mineralized with II iron and calcium salts.

Biology. In British Columbia, Gadilia aberrans is found in clean, well-sorted sand with about 5% i

organic material by weight; in the Santa Maria Basin, the sediments consist of mixed sand/silt. Foraminiferans 'II

are common in this habitat; depth distribution 20-100 m. Population densities are about 10 animals per m2.

Predator on small living foraminiferans (maximal dimension generally < 0.3 mm); prefers Cribrononion •

lene (Cushman and McCulloch, 1940) and Rosalina cf. columbiana (Cushman, 1925), eats Elphidiella II

hannai (Cushman and Grant, 1927) as encountered, and rejects or eats fewer than would be expected of

Florilus basispinatus (Cushman and Moyer, 1930) and Buliminella species. The most abundant minor prey i
!

I1

1 cm

| ',

!

!

I Figure 4.6. Gadita aberrans (Whiteaves, 1887).

!

species are Buliminella elegantissima (d'Orbigny, 1839) andB. exilis (H. B. Brady, 1884); other foraminiferan

i species are also taken. Prey is maintained in a buccal pouch (= proboscis) prior to trituration; and there may

be more than 125 foraminiferans in the pouch. GadiIa aberrans is a major infaunal predator where it is

found and may be important in determining the abundances of other infauna by its predatory activities

(Shimek, 1990).

t Remarks. Gadilia (= Cadulus) aberrans is the same as C. hepburni Datl, 1897, C.fusiformis

Pilsbry and Sharp, 1898, and C. nitentior Arnold, 1903. Shimek (1989) examined variation in shell

i morphometrics from populations of Gadilid scaphopods ranging from Vancouver Island to Southern California and concluded that the northern Gadila aberrans was indistinguishable from the northern C. hepburni and

the southern species, C.fusiformis and C. nitentior.

i 100 m. NTyMCpe (555). LocalitThe y anfollowing d Type Splectotypes ecimens. were Quatsino designated Sound, byVancouver Shimek (1988): Island, British C. hepburni, Columbia, Dall, in1897, 60-

(USNM 107612); from Near Victoria, Vancouver Island, British Columbia, in 120 m; C.fusiformis, Pilsbry

I 23729); and Sharp, 1898, (USNM 133809); from San Pedro, California, at 50 m; C. nitentior, Arnold, 1903, (USNM, from Pleistocene, Deadman Island, San Pedro bluffs, California.

Distribution. Southern California through Prince William Sound, Alaska (Shimek, 1989)

I Genus Siphonodentalium M. Sars, 1859

i Type Species: Siphonodentalium vitreum M. Sars, 1859.

Diagnosis. Shell cylindrical, very smooth and glossy, thin, pellucid, glassy; arcuate; apex relatively

i large, Ante with edges cut into lobes or teeth, slowly tapering from aperature to apex. Aperature cicular, oblique. rior aperature constricted, widest portion of shell posterior to aperature. Foot expanded into terminal

disk.

|

!

!
I

Siphonodentalium quadrifissatum (Pilsbry and Sharp, 1898) I

Figure 4.7

II

Cadulus quadrifissatus Pilsbry and Sharp, 1898:150-151, pI. 29.--Keen, 1971:889. I

Material Examined. California, Santa Maria Basin, Sta. 58 (3); Sta. PJ-22 (4); Sta. R-6 (4); Sta. R- II

2 (3).---Off Los Angeles, (CAS, 075696) (82); Orange County, Newport Bay, (CAS, 075702) (4); off San !

Diego, 20 m, (CAS, 075701) (6); off Santa Cruz Island, NW of Petican Bay, 64-71 m, (LACMNH, 41-81.2)

(2); NE of San Miguel Island, 64-71 m, (LACMNH, 41-58.3) (5).--Mexico, Guadelupe Island, 10-18 m, _1

(CAS,

(LACMNH,

075697)

65-43)

(4);

(5);

off

9

Guadelupe

m, (LACMNH,

Island,

71-22)

15-37

(27).

m, (LACMNH, 65-42.4) (34); off Mexico, 18-36m, m

Description. Shell slender, slightly tapering; middle third of shell slightly but perceptibly swollen; t

subtransparent, bluish, often with milky white bands parallel to anterior aperture found near larger end; |

smooth and rather glossy, growth lines hardly visible; posterior third slowly tapering, tube then nearly

cylindrical almost to aperture. Aperture oblique, circular to transversely oval. Dorsal apex cut into 4 conical l/

lobes by short slits; relative length and prominence of these teeth varying substantially, probably related to n

remodeling cycle of shell by animal; edges of lobes somewhat bevelled distally (Figure 4.7).

Shell Morphometric Indices. Derived from examination of 193 adult specimens. Shell maximum ill

width/shell length = 0.16 __.0.02; ln(Ws) = 5.49 +_1.25, (Ws = 634); WI = 0.85 _+0.06, LI = 0.47 _+0.10. n

Adult total shell length = 4.5 to I 1.9 mm, mean = 7.25 _ 1.37 mm, maximum width = 0.8 to 2.35 ram, mean

= 1.11 +_0.20 mm.

I Visible Internal Morphology. Gonads visible through adult shells; white in males, pink, in females;

ova brown or pink (Hebert, 1986; Levitt, personal communication).

Biology. In the Santa Mafia Basin, Siphonodentalium quadrifissatum occurred in sediments having i

high percentages of silts.

Remarks. The examined specimens appear to have a wide range of morphometric parameters. The I/

Santa Mafia basin material has lower length index values, LI < 0.45, than do most of the examined specimens, I

but statistically they are not significantly different from the total array of specimens, however; they may

represent either an ecotopic or populational variant. Other morphological differences became apparent with I1

the examination of the distributional material. These differences included decidedly different shell thicknesses, I

whorl expansion rates, and maximum widths. Unfortunately, there were no clear correlations between any

of these morphological characteristics and either habitats or localities. Habitat or locality data given with '1

!

_i...'. ". ' - " • . " .... :",' "-" ...... _'-'"'=' "," '::' "" " " "_-.--._7_

,i

250 ,urn L I

!

Figure 4.7. Siphonodentalium quadrifissatum (Whiteaves, 1887). n

90 |
!

I the specimens, however, were often quite limited. Siphonodentalium quadrifissatum in the central California

region may be a single variable species. Alternatively, there may be several, perhaps three or more, species

i with the same general characteristics, i.e., slender gadilids with four fissures and apical lobes, living sympatrically in the area. I believe this latter hypothesis to be correct, but to separate these taxa statistically

using only shell morphometric characteristics may be impossible. Examination of living animals is required

i • with reference Type Loca to their lity ecological and Type requirements; Specimens. Sanparticularly Diego, Calif habitat ornia,and10dietary m; CAS. preferences.

Distribution. Monterey Bay to Baja California (Keen 1971).

!

Family Pulsellidae Scarabino, 1982

I Genus Pulsellum Stoliczka, 1868

i Type Species: Siphonodentalium lofotense M. Sars, 1864. Diagnosis. Shell cylindrical, smooth, may be glossy, thin, arcuate; slowly tapering from aperature

to apex; apex lacking lobe and teeth. Aperature circular, oblique. Adult anterior aperature either not constricted,

I or only slightly constricted; widest portion of shell posterior to aperature. Foot expands into terminal disk with single terminal filament.

Remarks. No specimens of PulseUum have been observed from the Santa Maria Basin collections,

however it is that P. salishorum be encountered. See the for differential characters. likely might key

I Acknowledgements

i I thank the curators and staff of the California Academy of Sciences, Los Angeles County Museum of Natural History, and National Museum of Natural History (Smithsonian Institution) for their kind and

prompt assistance in providing types and other specimens. The Academy of Natural Sciences (Philadelphia)

i did not provide types, and to the extent that I was not able to examine those specimens, this report suffers.

i Literature Cited

Abbott, R. T. 1974. American Seashells. Van Nostrand Reinhold Co. New York. 633 pp.

I Arvy, L. and Gabe, M. t951. Donnees morphologiques sur le sang du Dentale. Bull. Lab. Dinard 35: 15-22.

Baxter, R. 1987. Mollusks of Alaska. Shells and Sea Life Publications. Bayside, CA. 163pp.

tl Bilyard, G. R. 1974. The feeding habits and ecology of Dentalium entale stimpsoni Henderson. (Mollusca: Scaphopoda). The Veliger 17:t26-138.

i Boissevain, M. 1904. Beitr_ige zur Anatomie und Histologie von Dentalium. Jenaische Zeitschrift fiir • Naturwissenschaftlich - Medizinsche Grundlangenforschung 38: 553-572.

Carpenter, P. P. 1864. Supplementary report on the present state of our knowledge with regard to the mollusca

I of the West Coast of North America. Report of the British Association for the Advancement of

Science for 1863: 517-686. [1864, Aug]:603,648.

I

| 91
I

Chistikov, S.D. 1975. Some problems in the classification of the order Dentaliida (Mollusca: Scaphopoda). I

Science [Nauka] Leningrad Section:18-21. Abstract translated in: Emerson, W. K., 1978.

Malacological Review 11:71-73. i_

Dall, W. H. t897. Notice of some new or interesting species of shells from British Columbia and the adjacent !1

region. Bulletin Natural History Society of British Columbia 2:1-18.

Dinamani, P. 1964a. Burrowing behavior of Dentalium. Biological Bulletin 126:28-32. i

Dinamani, P. 1964b. Feeding inDentalium conspicuum. Proceedings of the Malacological Society of London

36:1-5. I

Dufresne-Dube, L., Picheral, B. and Guerrier, P. 1983. An ultrastructural analysis of Dentalium vulgare

(Mollusca, Scaphopoda) gametes with special reference to early events at fertilization. Journal of in

Ultrastructure Research 83:242-257. 11

Emerson, W. K. 195I. A new scaphopod species CadMus austinclarki from the Gulf of California. Journal

of the Washington Academy of Sciences 41:24-26. /

ll

Emerson, W. K. 1952. Generic and subgeneric names in the molluscan class Scaphopoda. Journal of the

Washington Academy of Sciences 42:296-303. _ll

Emerson, W. K. 1962. A classification of the scaphopod mollusks. Journal of Paleontology 36:76-80. Ii

Emerson, W. K. 1978. Two new Eastern Pacific species of Cadulus, with remarks on the classification of ik

the scaphopod mollusks. The Nautilus 92:117-123. !1

Fisher-Piette, E. and A. Franc. 1968. In: Grasse, P. P. (ed.), Traite de Zoologie: Anatomie, Systematique,

Biologie. Mollusques, Gasteropodes et Scaphopodes. Classe des Scaphopodes. Vol. 5, 5, Fascicle I

3:987-1017. In

Fol, H. 1889. Sur l'anatomie microscopique du Dentale. Archives de Zoologie Exp6rimentale et G6n_rale HI

7:91-148. II

Gabe, M. 1949. Sur la presence de cellules neurosecretiques chezDentaIium entale. Comptes Rendu Academie

de la Sciences, Paris 229:1172-1173. B

Ill

Gabe, M. and Prenant, M. 1950a. Donnees histologiques sur le tissue conjonctiv du Dentale. Bulletin de la

Societ_ Zoologique de France 75:10-18.

Gabe, M. and Prenant, M. 1950b. Recherches sur la gaine radulaire des Mollusques. I. La gaine radutaire de g

Dentalium entale Deshayes. Archives de Zoologie Exp6rimentale et G6n6rale 86:487-498.

Gainey Jr., L. F. 1972. The use of the foot and the captacula in the feeding in Dentalium. The Veliger 15:29- i

34.

Grant IV, U. S. and H. R. Gale. 1931. Catalogue of the Marine Pliocene and pleistocene Mollusca of California t

and adjacent regions. Memoirs of the San Diego Society of Natural History 1:1-1034. II

Gray, J.E. 1847. A list of the genera of recent Mollusca, their synonyms and types. Proceedings of the mlt

Zoological Society of London 15:178. I

Hebert, A. 1986. Reproductive behavior and anatomy of three central Californian scaphopods. Unpublished

Master of Science thesis, California State University, Hayward, and the Moss Landing Marine Ill

Laboratories. v + 71 pp. It

I
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I Henderson, J.B. 1920. A monograph of the East-American scaphopod Mollusca. Bulletin of the United

States National Museum 111:1-177.

Keen, A. M. 1971. Sea shells of tropical West America. Stanford University Press. Stanford, California. pp.

II 883-891.

i Kraeuter, Knudsen, J. 1964. Scaphopoda and gastropoda from depths exceeding 6000 m. Galathea Report 11: 125-127. J. N. 1971. A taxonomic and distribution study of the Western North Atlantic Dentaliidae (Mollusca:

,_ Scaphopoda). Unpublished Ph.D. dissertation, University of Delaware, Newark. 256 pp.

I Lacaze-Duthiers, F. J. H. 1856. Histoire de I'organisation et du drveloppement du Dentale. Annales des

Scirnces Naturelles (ZooL) 4(6):225-281.

I Lacaze-Duthiers, Scirnces Naturelles F. J. H. 1857. Histoire de l'organisation et du drveloppement du Dentale. Armales des (Zool) 4 (7):319-385.

Leon, McFadien-Carter, N. 1894. Zur Histo M. logie des Dentalium mantels. Jenaische Zeitschrift 29:411. S. 1983. Interrelation of shell form, soft part anatomy and ecology in the

siphonodentalioida (Mollusca, Scaphopoda) of the North West Atlantic continental shelf and slope.

I Unpublished Ph.D. dissertation, University of Delaware, Newark, xvi + 214 pp.

Morton, J. E. 1959. The habits and feeding organs of Dentalium entalis. Journal of the Marine Biological

i Association of the United Kingdom 38:225-238. Palmer, C. P. 1974. A supraspecific classification of the Scaphopod Mollusca. The Veliger 17:115-123.

i Pilsbry, H. A. and B. Sharp. 1897-1898. Class Scaphopoda. In: Tyron, G.W., Jr. and H. A. Pilsbry, Manual of Conchology, series 1, 17: xxxii + 144 pp. [1897]; 145-280 pp. [1898], pls. 1-39.

Plate, L.H. 1892. Ober den Ban und die Verwandtschaftsbeziehungen der Solenoconchen. Zoolologisches

I Jahrbuch Anatomie 5:301-386.

Poon, Perry A. 1987. The diet and feeding behavior of Cadulus toImiei Dall, 1897 (Scaphopoda:

i Raup, D.Siphonodentalioida). 1966. Geometric analysis The Nautilus of 101:88-92. shell coiling: general problems. Journal of Paleontology 40:1178-

1190.

J Raymond, W. J. 1904. A new Dentalium from California. The 17:123-124. Nautilus

Reynolds, P.D. 1988. The structure anddistribution of ciliated sensory receptors in the Scaphopoda (abstract).

American Zoologist 28:140A.

Reynolds, P. D. 1990. Functional morphology of the perianal sinus and pericardium of Dentalium rectius

(Mollusca: Scaphopoda) with a reinterpretation of the scaphopod heart. American Malacological

I Bulletin 7:137-146.

Reynolds, P.D. 1992. Mantle-mediated shell decollation increases posterior aperature size in Dentalium

I rectius (Scaphopoda: Detaliida). The Veliger 35:26-35.

Sahlmann, B. 1973. Untersuchungen zur Histologie und Nahrungsbiologie der Scaphopoden. Ph.D.

i I Dissertation. Christian-Albrechts Universit_t Kiel Institut fiir Meereskunde. 107 pp.

J |

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Scarabino, V. 1979. Les scaphopodes bathaux et abyssaux de l'Atlantique occidental (Systematique, I

distributions, adaptations). Nouvelle classification pour l'ensemble de la classe. 154 pp. Unpubl.

Doctoral Thesis, Universite D'Aix-Marseille II. U. E. R. Des Sciences de la Mer et de L'Enveronment. I

II Shimek, R. L. 1988. The functional morphology of scaphopod captacula. The Veliger 30:213-221.

Shimek, R. L. 1989. Shell morphometrics and systematics: A revision of the slender, shallow-water Cadulus I

of the Northeastern Pacific (Scaphopoda: Gadilida). The Veliger 32:233-246. !1

Shimek, R. L. 1990. Diet and habitat utilization in a Northeastern Pacific Ocean scaphopod assem-blage.

American Malacological Bulletin 7:147-169. I

u

Shimek, R. L. and G. Steiner. Scaphopoda. In: Kohn, A.J. and F. Harrison (eds.), Microscopic Anatomy of

Invertebrates. Moilusca. (In Press). _l_

Simroth, H. 1894a. Bemerkungen fiber dei Morphologie der Scaphopoden. Z. Naturwiss. 67: 239-259. 11

Simroth, H. 1894b. Scaphopoda. In: Bronn: Klassen und Ordnungen d. Thierreichs 31: 356-467. .]_

Sokal, R. R. and F. J. Rohlf. 1981. Biometry. W. H. Freeman and Company. New York. 859 pp. m

Starobogatov, Ya. I. 1974. Ksenokowhii i ikh znachenive dlya filogenii i sistemy nekotorykh klass I

mollyuskov. Paleont. Zhur. 1974 (1): 3 - 18. (Trans. in: Paleont. Jour. 1 - 13). il

Steiner, G. 1990. Beitr_ige zur vergleichenden Anatomie und Systematik der Scaphopoda (Mollusca). Ph.

D. Dissertation, University of Vienna. I

Steiner, G. 1992. Observations on the anatomy of the scaphopod mantle and the description of a new family,

the Fustiariidae. American Malacological Bulletin 9:t-20. mll

STSC, Inc. 1986-1991. Statgraphics. Statistical Graphics Corporation. RockviUe, Maryland. IN

Talb, N.T. I976. Anatomy, Histology and Histochemistry of the Alimentary Canal of Dentalium entalis m

L.,with some observations on living animals. Ph.D. Dissertation. Univ. Glasgow. vii + 128 pp. II

Talb, N. T. 1981a. Gross anatomy of the alimentary canal of Dentalium entalis L. (Scaphopoda). Journal of

the College of Science, University of Riyadh 12:139-145. I

m

Taib, N. T. 1981b. Sites of Absorption and Food Storage in the Gut of Dentalium entaIis L. Journal of the

College of Science, University of Riyadh 12:147-154.

11 Van Dongen, C. A. M., Geilenkirchen, W. L. M. 1974a. The development of Dentalium with special reference

to the significance of the polar lobe. I. Division chronology and development of the cell pattern in

Dentalium dentale (Scaphopoda). Proc. K. Akad. Wet. Ser C. 77: 57-70. i

w

Van Dongen, C.A.M., Geilenkirchen, W. L. M. 1974b. The development of Dentalium with special reference

to the significance of the polar lobe. II. Division chronology and development of the cell pattern in 111

DentaIium dentale (Scaphopoda). Proc. K. Akad. Wet. Ser C. 77: 71-84. |

Van Dongen, C. A. M., Geilenkirchen, W. L. M. 1974c. The development of Dentalium with special reference

to the significance of the polar lobe. HI. Division chronology and development of the cell pattern in I

Dentalium dentale (Scaphopoda). Proc. K. Akad. Wet. Ser C. 77: 85-100. It

Van Dongen, C. A. M., Geilenkirchen, W. L. M. 1975. The development of Dentalium with special reference it

to the significance of the polar lobe. IV. Division chronology and development of the cell pattern in |

DentaIium dentale (Scaphopoda). Proc. K. Akad. Wet. Ser C. 78: 358-375.

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I Vouvelle, J. and M. Grasset. 1983. Biomineralisation des dents radulaires ches Dentalium dentalis L. Haliotis

13:123-130.

Wada, S. K. 1968. Mollusca I. Amphineura, Gastropoda, Scaphopoda, Pelecypoda. In: Kume, K. and K. Dan (eds.). Invertebrate Embryology. pp. 485-525. The NOLIT, Publishing House, Belgrade.

i Whiteaves, J. F. 1887. On some marine invertebrates dredged or otherwise collected by Dr. G. M. Dawson, • in 1885, in the northern part of the strait of Georgia, in Discovery Passage, Johnstone Strait, and

Queen Charlotte and Quatsino Sounds, British Columbia; with a supplementary list of a few land

and fresh water shells, fishes, birds, etc., from the same region. Transactions of the Royal Society of

I Canada 4:124, fig. 2.

Wilson, E.B. 1904. Experimental studies on germinal localisation I: The germ regions of Dentalium. Journal

I of Experimental Zoology 1:1-72.

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I 5. CLASS BIVALVIA

| by

Paul H. Scott 1

I

i Introduction

I The classTheis bivalves exclusivelycomprise aquatic,a major thoughclass someof intertidal invertebrates, specieswithcanabout survive 8,000many livingdays species out of(Boss, water,1982). and

inhabitants of ephemeral lakes can aestivate in moist sediments for several months. Bivalves are found in all

I aquatic habitats, from lakes at high elevations and temporary rain ponds to the deepest reaches of the oceans. They range in size from adults that attain less than one millimeter in length to tropical species with shells

nearly 2 meters long.

I were frequently Bivalve collected shells werewashed amonguptheonfirst beaches, biological skeletons samples divorced returnedfrombytheearlysoftexploring parts thatexpeditions secreted them. and

Much early work was done excusively with shells, leading to many misconceptions. While identifications

I ofsomemostknowledge taxa may beof based anatomy. entirelyFurther, on shell athough characters, asignment an understanding to higher taxa of thecanfunbectionlargely of thebased shell reonquires shll

characters, including microstructure, the study of anatomy assists in the identification of relationships and

i establishesMostevolutionary trends. bivalves feed on small particles, and even carnivorous forms, lacking jaws or a radula, are not

able to chew or break up food and have poor muscular equipment to manipulate food into the mouth. The

I only valves.exception The is the Teredinidae, which mechanically rasps burrows in wood with the serrated ends of its raspings have secondarily become food for the shipworms. The microphagous behavior has

limited the type of food available. In spite of the severe constraints imposed by enclosure in a rigid shell, an

i _ inability to protrude the mouth, and nutrition limited to the uptake of small particles, bivalves reveal a

I! remarkable diversity of life styles and habitats. The epifaunal situation is probably primitive and is prevalent

in many unrelated lineages. In addition, some lineages that have become infaunal have then given rise to

I groups development that have of siphons, returnedandto exp arogression lore the epifaunal is apparent habit.fromThetheinfaunal colonization siuationof generally friable andcorre softlates sdiments with theto

progressively harder and more refractory subslxata. The boring habit has been developed in eight superfamilies.

I Primiti penetration vely, isboring achievedwasbysolely chemical by mechanical means. means, but in Lithophaga and some other modern borers

A small number of bivalves are commensal, chiefly belonging to the Galeommatoidea. The only

I parasitic freshwaterbivalves bivalves,areandthearare few dwarf that occur malesin tha thetbuccal live inpouches a much oflarger holotfemale, hurians.theA number glochidialpossess larvaesymbiotic of some

algae within their pallial tissues, e.g., the giant clams (Tridacnidae) and in at least some of the closely allied

I Cardiidae.

!

1Department of Invertebrate Zoology, Santa Barbara Museum of Natural History, 2559 Puesta del Sol Road, Santa Barbara,

I California 93105 USA
!

A symbiosis with chemoautotrophic bacteria has been demonstrated for a number of unrelated I

groups that inhabit sulfur-rich environments. The f'trst discovered was the fascinating fauna around the

deep-sea hydrothermal vents and sulfide seeps. Then, similar communities were discovered in sulfide and all

petrochemical seeps in shallower water, followed by the discovery that some very shallow-water lucinoids II

possess chemoautotrophic bacteria in their ctenidia.

Glossary I

Accessory muscle. A muscle attached to the Buttress. Internal wall or projection supporting I

interior of the shell, other than the adductor hinge plate structures.

or pallial muscles.

Byssal gape. Opening between shell commisure 1

Accessory scar. Small attachment impressions on for passage of the byssus.

the shell interior made by other than the Illl

adductor and pallial muscles. ByssalPectinidae notch. Furrow for passage in the right of thevalve byssus. of some _

Adductor muscles. Transverse muscle bundles

that bridge the valves and draw them Byssal sinus. Embayment in the right valve of II

some Pectinidae corresponding to the byssal _ii together. Usually one or two are present, notch.

rarely a third accessory adductor muscle

may be present. Byssate. With a byssus. Equivalent to byssiferous.

g

Adductor scar. Impression on inside of shell Byssus. Fibres secreted by glands associated with

where adductor muscles were attached, the foot used to anchore the bivalve to the ,1

substrate, or to construct "nests" and brood I

Mate. With wing-like projections, pouches.

Alivineular. A ligament usually centrally placed

and Byssiferous. With a functional byssus. I

with lamellar layers both anterior

posterior to fibrous layer (e.g. Ostrea). Calcite. Crystalline form of calcium carbonate.

Amphidetie. A ligament extending on both sides Cancellate. Sculpture of intersecting radial and _l

of the umbo (e.g. Glycymeris). commarginal raised structures. II

Auricle. Ear-like projections of the hinge line (e.g. Cardinal teeth. Teeth below the umbo, correctly ml

Chlamys). only applied to the Heterodonta. I

Auricular erura. Tubercles and ridges on the Cardinal erura. Narrow plate-like teeth radiating

hinge plate of some Pectinidae (singular: from the resilifer in some Pectinidae. _l

crus). Carinm Keel-like radial ridge on the outside of _

Aragonite. Orthorhombic form of calcium the shell. dl carbonate.

Cementation. Fixation to the substrate by shell

Beak. Projecting regions marking the early growth secretion.

of the the bivalve shell. Equivalent to umbo. Chondrophore. Elongate spoon-like process i

,U

Bifid. Divided by a groove. Usually applied to projecting from the hinge plate and

teeth, containing the resilium. In

Bifurcate. Divide into two. Usually applied to Clavicle, A narrow delicate buttress supporting I

sculpture, the hinge plate.

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I Commarginal. Parallel to the ventral shell margin Dysodont. With small denticles near the umbo.

and marking the direction of accretionary

growth. Usually applied to sculpture. Also Edentate. Hinge plate lacking dentition.

I called concentric. Ear. Lateral projecting of the hinge line in the

Pectinacea.

Commissure. Contacting margins of the two

i valves of the shell. Edentulous. see edentate.

Conchiolin. Protein material forming shell matrix. Entire. Pallial line lacking a pallial sinus.

Costa. Raised rounded portion of the shell Equilateral. With the umbo central and the surface, anterior and posterior parts of the shell

Crenate. With even notches or regularly nearly equal in size.

I corrugated. Equivalve. With the valves equal in size and

Cruciform muscle. Intersecting muscle bundles shape.

i Teltinacea. associated with the siphons in some Escutchumbo eon. andAreausually of hingemarginal line posterior to the ligament to the

Crura. a peduncle or tooth-like projection on the and differentiated by sculpture. Frequently

I hinge plate of some bivalves.

demarcated by margical a stria.

Crus. single limb of a crura. Eulamellibraneh. Complex gill with permanently

i C attached filaments, transverse plates of tenolium. A row of small teeth on the edge of tissue and vertical strenghening rods.

the byssal notch of some Pectinidae.

Euthetie. Oriented perpendicular to the substrate

I Dehiscent. Sloughing off, applied to periostracum. (e.g. Mytilus).

Demibranch. One of two plate of flaments Evanescent. Ephemeral structures, overgrown and

i D making up the gill on one side. lost in adult individuals. Usually applied to entiele. Tooth-like process, dentition (e.g. Serripes).

Fascicle. A bunch of radial ribs, present in some

i Dentition. Collective term for hinge plate teeth Chlamys.

and associated sockets.

Fibrous ligament, Portion of the ligament

Digestive diverticulum. Paired arborecent mass impreganated with calcium carbonate,

I of tubules attached to the stomach.

elastic to compressional stress.

Dimyarian. With two adductor muscles.

Filibraneh. Gill with free or temporarily attached

IF Disc. The central part of the external surface of the filaments.

'W valve, not including developments such as Fossette. Obsolete term for the resilifer.

the auricles and rostrum.

I Gape. Opening between valve commissure after

Dissoconch. The post-larval shell, sometimes closure of the shell.

retained on the apex of the umbo.

Divaricate. Branching, usually bifid and Gill. Respiratory, water transporting, and particle retaining organ of the majority of bivalves.

frequently, bifid, sculpture. Equivalent to ctenidium.

i Duplivine component ular. Ligament separatedwithintothea selame riesllar (e.g. Growthof check. the valveStrmarking ong concecessation ntric lineofoseasonal n surface

Arca). growth.

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Growth striae. Fine concentric lines on the Ligament groove. Narrow depression I

surface of the valve marking intervals in accomodating the Iigarnent.

growth. Ligament pit. Broad subumbonal depression I Hetermyarian. Having unequally sized adductor accomodating the ligament.

muscles. Lira. A minute raised area, usually between two /

Heterorhabdie. Gill with filaments differentiated, furrows. (plural: lirae), i

Hinge. Collective term for structures on the dorsal Lithodesma. An accessory tooth-like plate

commissure of the shell supporting the resilium, usually limited to I

the Anomalodesmata. tl

Hinge line. Long axis of the hinge plate.

Ltmule. Subcircular to heart-shaped depression in II

Hinge plate. Shell plaffrom bearing structures front of the umbo, usually with different associated with It the articuIation of the valves

of the shell, sculpture and set off by marginal striae.

Mantle. Tissue plate investing the bivalve body I

Hirsute. Unevenly hairy, usually applied to and sometimes prolonged into siphons.

periostracum. (e.g. Modiolus).

Homorhabdie. Gill with all filaments alike. Monomyarian. With a single adductor muscle.

Mos 41aicostraeum. Thin boundary layer joining the

Hypobranehial gland. A glandular region periostracum to the shell.

associated with the gill and mantle in _l

protobranchs and may help consolidate Multivineular. Ligament type with serially |

rejecta, repeated alivincular elements,

Hypoplax. An accessory plate covering the Myostraeum. Attachment layer deposited on J

posterior ventral gape of some Pholadidae. muscle attachments. Ul

Imbricate. Overlapping like roof shingles, applied Nacreous. Shell microstmcture of thin aragonitic Ill

to sculpture, layers, characterized by iridescence. II

Inequilateral. Umbo not central and anterior and Nodose. Sculpture with tubercles or nodes.

Jan

posterior parts

of the shell different in size.

Nymph. Elongate platform on the hinge plate for I

Inequivaive. Shell valves unlike in size or shape, mechanical attachment of the external

Internal ligament. Alternative term for resilium, ligament. I

Opisthodetie. Term applied to ligament located

Integripalliate. Obsolete term for pallial line entirely posterior to umbo.

without a pallial sinus. (see entire).

Organ of Bojanus. The kidney of bivalves, two wDR

Interspace. Region between adjacent ribs. contorted tubules close to the heart.

Isomyarian. With equal sized adductor muscles. Orthocline. Perpendicular to hinge axis, usually I

Lalnella. A plate-like extension of the external with reference to dentition. mS

sculpture. Opisthogyrate. With umbo pointing posteriorly. /ill

Lamina. A thin plate of shell on the hinge plate. Orthogyrate. With umbones pointing towards [_l

Laneeolate. A long tapering form, usually applied each other. ill

to the lunule and escutcheon.

Ostium. Aperture between gill filaments for I

Ligament. Elastic proteinaceous structure linking passage of water (Plural. ostia).

the shell valves. 1

100 I
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I Pallial. Pertaining to the mantle. Prosodetic. Located anterior to the umbo, usually

Pallial line. Scar left on valve interior from applied to the ligament.

I attachment of marginal pallial muscles, Prosogyrate. Umbo pointing anteriorly.

Pallial sinus. Posterior embayment formed in Protoplax. Elongate accessory plate, sometimes

i pallial line to accomodate the siphonal divided longitudinally, covering anterior

retractor muscles, dorsal margin of some Pholadidae.

Palp proboscides. Two long protrusible organs Provinculum. The hinge plate of the

i used to convey detritus particles to the prodissoconch, bearing larval teeth.

mouth, limited to the paleataxodonts. Pseudocardinal. Subumbonal teeth with a

i Parivineular. Elongated external ligament different origin than those of the Veneridae. situated posterior to umbo. Pseudolamellibranch. Complex gill with

Pedal gape. Opening in shell commissure to filaments permanently fused.

Punctate. Surface with numerous small pits.

accomodate the foot.

Pedal muscles. Muscles attached to interior of the (Singular puncture, plural puncta).

i Per valve used to control the foot. Radial. Direction of growth away from the umbo. iostracum. Outer proteinaceous layer of the Usually used to describe sculpture.

shell. Equivalent to epidermis. Resilifer. Recess in the hinge plate to receive the

Perieardial gland. Tissue mass associated with resilium.

the pericardium and extending into the

Resilia. Linear series of figamental islets in some

i mantle. Equivalent to the Organ of Keber. alivincular ligaments. Pilose. Evenly and f'mely hairy, usually applied to

periostracum. Resilium. Internal portion of the ligament.

Equivalnet to cartilage.

I Pericalymna larva. Larval type of the

protobranch bivalves. Reticulate. Sculture of a network of intersecting elements, frequently oblique.

I Pleurothe planetic.(e.g. LyingPectionnidae). one valve in the sagittal Recurved. Bent.

Porcelaneous. Calcium carbonate with white, Rib. Prominent elevation forming sculpture,

I shorter and more compact than a costa.

translucent texture, usually forming interior

layer of the shell. Riblet. Small elevation forming sculpture.

Posterpoiorsteri sloope. r anSegment d ventralofofshell the uexteri mbo.or Rostrate. Pointed or beaked.

Rostrum. Elongation of shell forming a tube

i Primary ligament. Exterior part of ligament protecting the siphons.

representing the primitive condition of

• periostracal and fibrous layers. Sagittal plane. Anterior-posterior plane of

symetry of the shell or soft parts.

t Prismatic. calciticShell or armicrostructure agonitic prisms. consisting of Sculpture. Relief pattern on the shell exterior.

Prodissoconeh. Larval shell, frequently retained Siphon. Tube extensions of the fused mantle.

I on tip Siphonal retractors. Muscle used to withdraw the

the of the umbo.

siphons and attached to the pallial sinus.

i 101
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Spine. Long calcareous projecting sculpture. Umbo. Projecting region of the valve marking the I

earliest shell. Equivalent to beak. (Plural.

Squamate. Sculpture with small scales, umbones). l

Stria. Minute incised line sculpture. (Plural: Umbonal cavity. Dorsal chamber under the hinge I

striae), plate.

Suleus. Radial depression of the valve, usually

carried to the interior of the valve. Valve. One of the lateral calcareous plates that I

make up the shell.

Thread. Narrow elevation in sculpture, more Veliger. Larval stage of the majority of bivalves. robust that a lira. II

Vineulum. Secondary deposite of shell on the

Troehophore larva. Earliest larval form of all hinge plate submerging the dentition.

bivalves, not directly referable to the annelid _l

trochophora. Xenomorphic. Assumption in form and sculpture ,I

of the substrate in some cemented bivalves

Truncaabrupt te. Valve marginal curvature interupted by I segment. (e.g. Anomia). 11

Tumid. Inflated and prominent, usually applied to

umbones, i

Key to the Superfamilies I

1A. Hinge with taxodont dentition (reduced to a few teeth in some) .................................................... 2

1B. Hinge edentate or with other than taxodont dentition ..................................................................... 5 I

2A. Ligament internal ............................................................................................................................ 3 I

2B. Ligament mostly or entirely external ............................................................ Nuculanoidea (in part)

3A. Hinge teeth few in number, entirely or mostly on one side of beaks ....................... Manzanelloidea I

3B. Hinge teeth more than 8 and on both sides of beaks ....................................................................... 4

!

4A. Shell very iridescent internally ........................................................................................ Nuculoidea

4B. Shell porcellaneous (or slightly iridescent) ................................................... Nuculanoidea (in part) !

5A. Dorsal margin produced anteriorly and posteriorly into triangular ears, or ligament in series of pits Ii

.................................................................... .................................................................................... 6 I

5B. Dorsal margin not produced into ears; ligament not divided into series of pits ............................. 7

.|

6A. Shell much higher than long; ears small ............................................................................ Limoidea

6B. Shell height and length more or less similar; ears large ................................................. Pectinoidea t 

I

102 I
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I 7A. Hinge simple, without conspicuous interlocking cardinal teeth, projecting chondrophores, or

myophores (may have inconspicuous denticles or a resilifer on hinge plate, or left valve may fit into

i 7B. Hinge lateral grooves complex,inwith righ2t valv or more e) .......................................................................................................... interlocking cardinal teeth in at least one valve (may als__.__o have 8a

chondrophore) ............................................................................................................................... 19

I 8A. Adductor muscle scars very unequal in size; anterior scar smaller, near beaks; beaks anterior in

most .................................................................................................................................. Mytiloidea

i 8B. Adductor muscle scars of approximately same size; beaks not anterior ........................................ 9

I 9A. Periostracum produced well beyond shell margin ....................................................... Solemyoidea 9B. Periostracum, if conspicuous, not produced well beyond shell margin ........................................ 10

I 10A. Shell porcelaneous within ............................................................................................................. 11

10B. Shell nacreous within .................................................................................................................... 17

!

11A. Shell rudimentary, without true hinge ....................................................... Galeommatoidea (some)

I 1lB. Shell normal; valves connected by hinge ...................................................................................... 12

12A. Valves closing tightly .................................................................................................................... 13

I 12B. Shell gaping ventrally or anteriorly ................................................................................ Hiatelloidea

I 13A. With a conspicuous pallial sinus .................................................................................... Thracioidea 13B. Without a pallial sinus ................................................................................................................... i4

I 14A. With conspicuous radial ribs, mostly on posterior end ................................... Cuspidarioidea (part)

14B. Radial ribs absent or feeble ........................................................................................................... 15

!

15A. Ligament sunken onto hinge plate, not under beaks ................................ Lucinioidea (Thyasiridae)

'1 15B. Ligament internal under beaks ...................................................................................................... 16

16A. Sculpture of conspicuous commarginal ribs ............................................ Myoidea (Spheniopsidae)

I 16B. Surface smooth ................................................................................................ Cuspidafioidea (part)

I 17A. 17B. Without Internal dorsal crurae surface with crurae ........................................................... Pandoroidea (Pandoridae) ............................................................................................................................... 18

j 18A. Shell ovoid ................................................................................................................ Verticordioidea

18B Shell elongate, subquadrate ........................................................................... Pandoroidea (Lyonsia)

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19A. Shell cemented to substratum by 1 valve ........................................................................ Chamoidea 1

19B. Shell not cemented ........................................................................................................................ 20

! 20A. Shell with radial ribs over most of surface, showing as crenulations within (reduced in some to

internal crenulations only) ............................................................................................................. 21

20B. Sculpture absent, commarginal, cancellate, or only weakly radial ............................................... 22 I

2IA. Shell with anterior and posterior lateral teeth ........................................... Lucinoidea (Parvilucina) 1

2lB. Shell without lateral teeth, or with only an anterior lateral ............................................. Carditoidea

22A. Shell with an entirely internal ligament, or with partially intemal ligament ...... Galeommatoidea(part) I

22B. Shell with an entirely external ligament ........................................................................................ 23

!

23A. Shell with a conspicuous pallial sinus ........................................................................................... 24

23B. Shell pallial sinus absent or very shallow ....................................................................... Lucinoidea I

24A. Hinge with 3 cardinal teeth in 1 or both valves ............................................................... Veneroidea

24B. Hinge with 2 teeth in each valve .......................................................................... Tellinoidea (most) ,I i

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i Subclass Palaeotaxodonta Korobkov, 1954

• 8 Diagnosis. Shell cross-lamellar, porcellaneous or nacreous, equilateral to strongly inequilateral,

i III rounded to elongate, usually equivalve. Periostracum thin, adherent, varnished or dull. Sculpture weak to

very strong. Hinge plate strong, with replicated taxodont teeth or with a few horizontal teeth, edentate in

I some solemyoids. Ligament usually amphidetic (opisthodetic in a few), external or internal. Gills protobranch, usually large. Labial palps variable, palp proboscides usually present. Pallial line entire. Two subequal

adductor muscle scars, with other associated scars. Mantle lobes largely free. Foot with papillated planar

[ _ sole. Siphons present or absent. Larva a pericalymma.

I M Biology. The majority of species are deposit feeders and shallow infaunal dwellers. Palacotaxodonts

are a highly adaptable group in soft sediments with a very wide distribution and are frequently the dominant

I bivalves in the deep ocean and abyssal regions.

• The characteristic features of the subclass are the protobranch gill, the palp proboscides (except in

mlt the solemyoids), and the series of identical or similar vertical teeth, set in a row on the anterior and posterior

i I hinge plate. In some fineages, one limb of the chevron-shaped tooth becomes elongated, resulting

in horizontal

tamellar teeth. In the Order Solemyoida, dentition is absent or reduced to a few vertical and horizontal

elements.

!

Order Nuculoida Dall, 1889

[

Diagnosis. Shell aragonitic and inequilateral. Periostracum thick to thin, usually adherent and

i varnished. Umbones prominent, prodissoconch large in many species. Sculpture absent or weak. Hinge plate prominent with replicated taxodont teeth, usually vertical, rarely consisting of few horizontal teeth.

Ligament amphidetic or opisthodetic, usually internal. Adductor muscle scars nearly equal. Gills protobranch,

i small and situated posteriorly. Labial palps and palp proboscides large. Foot with byssal groove, sole flattened with papillated margin.

I Superfamily Nuculoidea J. E. Gray, 1824

Diagnosis. Shell aragonitic, usually less then 1 cm and inequilateral; interior nacreous. Inflated and

I equ withivalve, with a truncate posterior end. Periostracum adherent, usually dark colored. Hinge plate strong, series of V-shaped teeth separated by a resilifer. Ligament internal, amphidetic. Dimyarian; pallial line

weak; pallial sinus absent. Gill small, oblique to horizontal. Labial palps and palp proboscides large.

i I Hypobranchial gland present.

Family Nuculidae J. E. Gray, 1824 w

I

i

Diagnosis. Outline triangular to ovate, inequilateral and equivalve. Umbones posterior, opisthogyrate.

i Sculpture absent or of various combinations of radial and commarginal riblets or striae. Periostracum thick,

polished in many, dull in others, yellow to dark brown. Lunule strong to weak or absent; escutcheon wide

and frequently long. Hinge plate strong, with anterior and posterior series of V-shaped teeth separated by a

I deep resilifer. Adductor muscle scars subequal. Pallial line entire. Mantle lobes free. Foot large, with planar sole and byssal groove, but adult not byssiferous. Alimentary canal with type I stomach, strongly chitinised,

with two ducts leading to the digestive diverticula; style-sac and mid-gut conjoined; intestine long, convoluted,

i usually on the right side of stomach, passing through ventricle of heart.

i 105
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Genus Nucula Lamarck, 1799

ah

Nucula Lamarck, 1799. Type species (M): Arca nucleus Linnaeus, 1758. Recent, North Atlantic. I

Scu Diagnosis. Shell ovate to subtrigonal, inequilateral, inflated. Periostracum thin, adherent, polished. I i lpture absent or commarginal riblets and/or radial striae. Lunute and escutcheon usually present. Hinge

plate wide; taxodont teeth in two series separated by a short, oblique to subvertical resilifer. Ligament

amphidetic, internal. Ventral shell margin crenulate. I

m

Nucula carlottensis Dall, 1897

Figure 5.1 I

Nucula carlottensis Dall, 1897: 6.

Nucula charlottensis Dall, in Oldroyd, 1924: 5, nomen vanum !

Nucula (L.) keenae F. R. Bernard, 1983: 253.

Nucula (L.) takashii F. R. Bernard, 1983: 255. I

,m

Material Examined. California, Santa Maria Basin, Phase I, Sta. BSS-16 (591 m); Phase 1I, Sta.

PJ-1 (145 m), PJ-8 (145 m), PJ-9 (169 m). iN

,11 Description. Shell small, trigonal, very inflated. Sculpture of commarginal striae overlain by radial

striae. Periostracum yellow to dark brown, silky. Length to 10 mm.

Type Locality and Type Specimens. Off Queen Charlotte Islands, British Columbia, Canada;

types not found.

Distribution.Queen Charlotte Islands, British Columbia (51.4° N) [USNM], to Acapulco, Guerrem, dill

Mexico (16.9 ° N) [USNM], in 104 - 2,000 m. 11

I

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Figure 5.1. Nucula carlottensis: A, interior of left valve;B, exterior of left valve. 1
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Genus Ennucula Iredale, 1931

.!

; Ennucula Iredale, 1931. Type species (OD): Nucula obliqua Lamarck, 1819. Recent, Australia.

I Diagnosis. Oval; shell surface smooth; inner ventral margin without crenulations.

Eunnucula tenuis (Montagu, 1808)

i Figure 5.2

i Arca Nuculatenuis inflataMontagu, Hancock,1808: 184656. : 333, non J. Sowerby, 1827, non Wissman and Miinster, 1841.

Nucula expansa Reeve, 1855: 397, non Bronn, 1848.

Nucula bellotii A. Adams, 1856: 51.

Nucula tenuis "typica" G. O. Sars, 1878: 34.

I Nucula Nucula tenuis lucida Whiteaves, 1887: 120. quirica Dall, 1916: 9, nom. nud.; Dall, 1916: 394.

Nucula (Ennucula) balboana Hertlein and Grant, 1972: 145.

I Nucula (Leionucula) leptodonta F. R. Bernard, 1983: 255.

Material Examined. California, Santa Maria Basin, Phase I, Sta. BSS-50 (591 m), Sta. BSS-55

I (590 m), Sta. BSS-69 (927 m); Phase II, Sta. R-3 (409 m), PJ-8 (142 m), PJ-9 (142 m).--30 lots from southern California (SBMNH).

i Description. Shell ovate-trigonal, moderately inflated, smooth or with faint commarginal straie. Beaks near the posterior margin. Ventral margin smooth. Periostracum light olive to dark brown, usually

irridescient. Resilifer projecting, oblique, deep. Length to 17 ram.

I side of theTypeFirthLocofalit Forth, y and56Typ ° N,e02.5 Specime ° E; type ns. Near material Dunbar, not found, about presumably 30 mi east oflost. Edinburg, Scotland, south

Distribution. Circumboreal and Arctic Ocean (71 ° N), thoughout the Bering Sea and the Gulf of

I Alaska (60 ° N), to San Diego, California (32.7 ° N), in 10 to 927 m. Literature. Hertlein and Strong (1940: 382), Petersen (1978: 100-101).

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I

I Figure 5.2. Ennucula tenuis: A, exterior of right valve;B, interior of left valve.

I 107
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Eunnucula cardara (Dail, 1916)

Figure 5.3 i

Nucula cardara Dall, 1916: 9, nom. nud.; Dall, 1916b: 394.

Ledaphenaxia Dall, 1916: 11, nom. nud.; Dall, 1916b: 397. I

Material Examined. California, Santa Maria Basin, Phase ISta. 55 (590 m).--Holotype (see below).

Description. Shell ovate-elongate, moderately inflated, smooth. Beaks prominent, placed well back 1

of the posterior margin. Periostracum olive to dark brown. Prodissoconch prominent. Resilifer projecting,

vertical, deep. Length to 12 mm.

Type Locality and Type Specimens. Off San Diego, California; Holotype, USNM 265905. I

Distribution. Cape Flattery, Washington (48 ° N), to Cabo San Lucas, Baja California Star(23 ° N),

in 590 - 2,600 m. ._

L Ii iterature. Hertlein and Strong (1940: 383).

!

Genus Acila H. Adams and A. Adams, 1858

!

Acila H. Adams and A. Adams, 1858. Type species (S.D. Stoliczka, 187I): Nucula divaricata Hinds, 1843.

Recent, China. II

Diagnosis. Shell inequilateral, much longer anteriorly, ovate to subquadrate, eqivalve. Sculpture of

divaricate radial riblets. Periostracum thick, dark brown to yellow. Umbones opisthogyrate. Ventral shell Mini

margin crenulated. Interior nacreous. Hinge plate with narrow, oblique resilifer. 1

Literature. Schenck (1932, 1935, 1936), Slodkevich (1967).

!

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i.

1 ,

A a |

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Figure 5.3. Ennucula cardara: A, exterior of right valve; B,interiorof left valve.

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108 I
i

I Acila castrensis (Hinds, 1843)

Figure 5.4

I Nucula castrensis Hinds, 1843: 98.

Nucula divaricata Conrad, 1848: 432, non Hinds, 1843, non Valenciennes, 1846.

I Nucula lyalli W. Baird, 1863: 71.

Acila empirensis Howe, 1922: 96.

i Acila (TruncaciIa) beringiana Slodkevisch, 1967: 56.

Material Examined. California, Santa Maria Basin, Sta. 7; Sta. 103; plus 25 lots from southern

i CaliforniaDesc(SriBption. MNH).Shell ovate-subquadrate, inflated. Sculpture of divaricate ribs. Periostracum light olive

to darkbrown, frequently with adhering sediment and parasitic hydroids. Length to 20 mm.

I Type Locality and Type Specimens. Sitka, Alaska; type not located. Distribution. Kamchatka; Craig, Alaska (55.5 ° N), to Las Cruces, Baja California Sur (24.2 ° N), in

5 - 400 m. Also reported as early as the Miocene in western North America.

I Literature. Frizzell (1930), Hertlein and Strong (1940: 388-389), Kuznetsov (1961: 94-95), Morse

and Meyhrfer (1990), Stasek (1961, 1963: 92), Strathmann (1987: 320).

I

I

i

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I Figure 5.4. AciIa castreneis: A, exterior of fight valve;B, interior of left valve; C, dordal view of both valves.

I
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Order Solemyida Dall, 1889 I

Diagnosis. Shell only weakly calcified, inequilateral, rounded to elongate, equivalve. Periostracum i

thick and varnished, usually dark brown to black. Sculpture absent, except for incremental lirae, or weak

i

radial ribs and furrows. Interior porcellaneous. Hinge plate edentate, or with several vertical teeth, or obscure aim

tubercles. Dimyarian or monomyarian. Gills protobranch, large. Siphons absent. Labial palps and palp i

proboscides reduced or absent. Foot with flattened sole.

Superfamily Solemyoidea J. E. Gray, 1840 i

Diagnosis. Shell strongly inequilateral, anterior elongate, equivalve. Periostracum thick, varnished. 1

Dimyarian. I

Remarks. One living family that is very widely distributed but absent in the frigid polar seas. The

family is adapted for survival in regions of high organic content and low oxygen tension. Most species have

symbiotic chemoautotrophic bacteria in their tissues, on which they depend at least to some degree for i

nutrition. In all species, the alimentary canal is reduced, and may be completly absent.

!

Family Solemyidae J. E. Gray, 1840

lml

Diagnosis. Shell aragonitic, with outer prismatic and inner homogenous layers. Inequilateral, I

anteriorly elongated, the shell is weakly calcified and dominated by the thick, varnished periostracum,

which extends beyond the shell margins. Sculpture absent, or limited to low wide radial ribs or furrows, i

Umbones small. Lunule absent; escutcheon weak or absent. Hinge plate weak, edentate, tubercles and I

thickened props usually present. Ligament parivincular, opisthodetic, sunk in a groove posterior to the

umbones and attached to nymph. Adductor muscle scars paired, subequal. Pedal muscle scars prominent. I

Pallial line obscure, entire. Mantle lobes with hypertrophied margins extensively fused, leaving large antero- |

ventral and small posterior openings. Hypobranchial gland developed. Foot elongate with discoid sole.

Gills protobranch, large; filaments thickened and dark coloured. Labial palps minute. Alimentary canal lit

reduced to simple tube with 2 ducts to the small digestive diverticula and a narrow intestine passing through I!

the ventricle of the heart. In some representatives, the entire alimentary system is absent. Larva a pericalymma.

Remarks. This family is represented by shallow infaunal burrowers in soft substrates. The vernacular

name, "awning clams," refers to the periostracal fringe projecting beyond the shell margins and usually II

dissected into triangular sections covering the wide, muscular, fused mantle margins. The calcareous portion

of the shell is weak and contains a large amount of organic matrix. The result is that the soft parts are _1

enveloped in a largely periostmcal flexible tube, stiffened along the dorsal margins by the shell valves. The i

high solubility of calcium carbonate in the deep ocean means that even recently dead specimens are represented

by the periostracum only, and the ventral margins become separated and result in the characteristic awning IN

shape. II

Biology. A complex Y-shaped burrow, with no direct communication with the surface may be

constructed by smaller species, but large individuals appear to lie at an oblique angle just below the sediment

surface, usually in a small depression in the sediment. All species observed appear to be active animals, Ii

vigorously burrowing through the substrate, and even capable of undirected swimming by adduction, although

this has been observed only in specimens artificially displaced from their burrows. The powerful pumping

action is probably associated with clearing the burrow. The family appears to favor regions of reduced II

oxygen, usually with high organic content.

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110 I
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I While the majority of species have a normal functioning alimentary canal, an outstanding feature is

the reduction of the gut to a simple tube with barely distinguishable stomach, or its entire loss in some

i species. It has recently been shown that nutrition is obtained from chemoautrophic bacteria mostly housed in the thick gill filaments. The bacteria utilize hydrogen sulphide to fuel the production of carbohydrates

and are able to exist in oxygen-poor environments. The clams live symbiotically with the bacteria and are

able to colonize enviroments with decomposing organic remains, high in hydrogen sulfide and poor in

I oxygen.

The typical location for awning clams in the northeastern Pacific is in basins on the continental

toshelf colonize and nearshore the shallowwhere watertherearound is ansewage accumulaandtiodebris n of plant from debris. log storage One areas. speciesThose is opportunis species twith ic andstomachs is able

have a tess restricted habitat and are generally absent from such polluted habitats. The question whether loss

i of beentheopened gut is abysecondary adaptation to exploit available habitats, or a carry-over of an ancient life-style, has the recent discovery of several organisms, including bivalves, part of a food-chain entirely

dependent on inorganic chemicals derived from volcanic activity of deep-ocean rifts.

I Genus Solemya Lamarck, 1818

Solemya Lamarck, 1818. Type species (S.D. Children, 1823): S. mediterranea Lamarck, 1818, = Tellina

I togata Poll, 1795. Recent, Mediterranean. Solenimya, Solenomya, of authors, nomen vanum.

Diagnosis. Shell inequilateral, elongate, inflated to compressed, usually equivalve. Shell weak without

I external sculpture except for weak radial ribs or furrows. Periostracum dominating shell, thick and varnished, extending beyond shell. Umbones not prominent, near posterior end. Hinge plate weak, edentate, with

oblique resilifer with or without supporting buttresses. Ligament opisthodetic, internal. Posterior adductor

I scar small; anterior scar large, continuous with oblique pedal retractor scar.

Solemya reidi F. R. Bernard, 1980

I Figure 5.5

i Solemya (Solemya) reidi F. R. Bernard, 1980: 19. Material Examined. 5 lots from southern California (SBMNH)

Description. A medium-size, dark brown species, characterized by a thick periostracum. Posterior

I ribs low, broad, and widely spaced. With an internal radial strengthening rib. Lacking an alimentary canal.

Length to 60 mm.

- Canada; Type Holotype, LocaliNMC ty and Type Specimens. Texada Island, northern Straight of Georgia, British Columbia, 86074.

Distribution. Southeast Alaska (55.3 ° N) to Santa

I Mfromonica, 40-600 Californi m, ausually (34 ° N)informi areasngofdehigh nse coorganic lonies

content and low oxygen levels; often present near

I effluent outfalls and log storage areas.

I Figure 5.5. Solemya reidi: exterior of right valve.

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i 111
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Remarks. The reduction of the alimentary canal has long been known in the genus, but this was the I

first species recorded with no gut in the adult. The larva has a complete alimentary system, which is lost at

metamophosis. This species was long confused with S. panamensis Dall, 1908, which does not occur north am

of Oaxaca, Mexico (16 ° N), and differs in being more elongate and in having finer posterior ribs. It is not I!

known whether the latter also lacks a gut. Both merit comparison with Solemya atacama Kuznetzov and

Shileiko, 1984, described from Peru. ill

Literature. Felbeck (1983), Felbeck et al. (1981), C. R. Fisher and Childress (1984), R. G. Gustafson 1

and R. G. B. Reid (1986, 1988a, b), R. G. Gustafson et al. (1987), McMahon and R. G. B. Reid (1984),

Powell and Somero (1985, 1986), R. G. B. Reid (1980), R. G. B. Reid and F. R. Bernard (1980), Strathmann l_

(1987: 320). I

Superfamily Manzanelloidea Chronic, 1952 i

= Nucinelloidea Vokes, 1956

Diagnosis. Shell subequilateral, small, nuculoid and equivatve. Umbones subcentral. Periostracum i

thin, polished. Ligament external and opisthodetic, sometimes sunken in marginal grove. Hinge plate strong

and short, with few vertical teeth; lateral dentition present in some. Dimyarian or monomyarian. Gill

protobranch. II

Remarks. One living family with cosmopolitan distribution in warm and temperate regions, but I

penetrating into the deep sea, is recognized. 1

The placement of this superfamily is not certain. It has been questionably included with the limopsids,

but the anatomical structure shows it to be close to Solemya, and the shell structure is closer to Nuculana. D

There is little evidence to support the contention that it represents an actinodont lineage. The bipinnate I

protobranch gill, present in all representatives of the superfamily, is strong evidence of affinity with the

paleotaxodonts, as it is not unlikely to have developed independently in unrelated groups. This superfamily am

is sparsely cosmopolitan and known from the Permian. •

g

t

Family Manzanellidae Chronic, 1952 i

= Nucinellidae Vokes, 1956; Huxleyidae Scarlato and Starobogatov, in Nevesskaia et al., 1971

Diagnosis. Shell aragonitic, 2-1ayered,inequilateral, usually higher than long, equivalve. Periostracum I

thin and varnished. Sculpture absent, or of incremental striae. Umbones prominent. Interior porcelaneous;

ventral margins smooth. Ligament opisthodetic, external, but may be sunken into a fossette. Anterior adductor _.

scar large, posterior scar small or absent. Pallial line entire, sinus absent. Mantle lobes widely open. Gills II

large, protobranch. Labial palps minute, palp proboscides absent. Alimentary canal absent or reduced, stomach

with chitinous lining; style sac and mid-gut conjoined. Intestine traversing ventricle of the heart. Foot II

developed; flattened sole longitudinally divided and fringed with papillae. II

Remarks. This family, originating in the early Jurassic, is probably derived from the Permian

Manzanellidae. Manzanella has approximately equal adductor muscles, and its ligament was probably

external.

One species, Nucinella maxima Thiele and Jaeckel, 1931, lacks an alimentary system and is similar

to the solemyids. J. A. Allen and Sanders (1969) considered Nucinella a monomyarian solemyid. Two i

living genera are known and include 12 species widely distributed in the lower latitudes in shallow to deep WB

water. Nucinella has an external ligament and only one adductor muscle. It seems premature to divide this

family into two separate families, as has recently been done. I

112 I
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I Genus Huxleyia A. Adams, 1860

I HuxleyiaA.A.Adams, Adams,1860. 1860 Recent, (April) [Korea. not preoccupied by Huxleya Dyster, 1858]. Type species (M): H. sulcata

Cyrilla A. Adams, 1860 (June), unnecessary replacement name for Huxleyia A. Adams, 1860.

I Diagnosis. Shell minute, inflated, inequilateral, ovate, usually oblique and equivalve. Periostracum

thin and varnished. External sculpture absent. Umbones prominent, posterior. Hinge plate wide, with several

vertical Dimyarian. teethPallia and] alineshort entire. lateral tooth. Ligament opisthodetic, chiefly internal in subumbonal fossette.

Remarks. Eight species are included in this genus, distributed in the Indo-Pacific to east Africa and

I Japan, and are known from the Pliocene to Recent. The name is in honor of the British naturalist T. H. Huxley. The gender of the genus, not the naturalist, is feminine.

I Huxleyia (Dall, 1898)

munita

Figure 5.6

I Cyrilla munita Dall, 1898: 602, ex Carpenter MS.

Nucula petriola Dall, 1916: 9, nora. nud.; Dall, I916b: 395.

Material Examined. California, Santa Mafia Basin, Phase I, Sta. 36 (492 m); Phase II Sta. R-7

(565 m).

I bearing 6Dor escfewer ription.vertical Shellteeth minuposterior te, inflated, to awith deepvarnished, subumbonal darkfossette. brown periostracum Strong lateral and toothwipresent de hingein plright ate

valve fitting into deep groove in left valve. Length to 3 mm.

I Remarks. This species cannot be confused with Nucinella subdola (A. M. Strong and Hertlein,

1937), a Panamic species with a much smaller fossette and only one adductor muscle. Huxleyia pentadonta

Scarlato, 1981, which is endemic to the Sea of Okhotsk, differs in being more quadrate.

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Figure 5.6. Huxleyia munita: A, exterior of fight valve;B, interior of left valve; C, dorsal view of both valves.

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i 113
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Distribution. Off Cape Alava, Washington (48.1 °N) [SBMNH], to PuntaSan Pablo, Baja California I

[Norte] (27.2 ° N) ILACM], in 70 - 750 m, in soft substrata and course sand. Also in the Pliocene or Pleistocene

of southern California.

Literature. Hertlein and Strong (1940: 419), A. D. Howard (1953: 235-237), E. J. Moore (1983: B

59).

Ill

Superfamily Nuclanoidea H. Adams and A. Adams, 1858 i

Diagnosis. Shell aragonitic, longer posteriorly, usually elongate and equivalve. Periostracum smooth

to varnished, olive to dark brown. Surface smooth, or with strong commarginal sculpture. Lunule and I

escutcheon present or absent. Hinge plate strong, with regular vertical taxodont dentition. Ligament

amphidetic, internal or external; resilifer present or absent. Adductor muscle scars subequal. Mantle lobes 1

fused posteriorly, sometimes siphonate. Gills protobranch. Palp proboscides present.

Remarks. The superfamily is distinguished from the Nuculoidea by the more elongate shell with a

porcellaneous interior. The inhalant current is posterior, and siphons are usually present. S

III

Family Nuculanidae H. Adams and A. Adams, 1858 I

Diagnosis. Shell aragonitic, homogeneous. Inequilateral, elongate, posterior usually rostrate.

Umbones anterior. Sculpture absent, or with weak commarginal lirae, rarely scissulate. Periostracum thin •

and varnished, usually yellow to dark brown. Hinge plate strong, arched, with 2 series of chevron-shaped g

teeth separated by resilifer or chondrophore. Ligament amphidetic, partially internal. Adductor muscle

scars subequal, or with anterior larger. Pallial line weakly impressed; sinus small to large. Mantle lobes not i

fused ventrally, posteriorly forming siphonal openings. Gills protobranch usually large. Hypobranchial I

glands absent. Labial palps long and narrow. Palp proboscides large. Foot with papillated plantar sole.

Adult not byssiferous. Alimentary canal with type I stomach and a long, convoluted intestine; style-sac not B

joined to mid-gut; three ducts from stomach to digestive diverticula; rectum passing through ventricle of !1

heart.

It

Genus Nuculana Link, 1807

Nuculana Link, 1807. Type species (OD): Area rostrata Brugui_re, 1789, ex Chemnitz MS, =Mya pernula I

Miiller, 1779. Recent, North Atlantic.

Schumacher, 1817. Type species (OD): Area rostrata Brugui_re, 1789, ex Chemrfitz MS, = Mya i

Leda

pernula Miller, 1779.

w

Diagnosis. Shell equivalve, usually rather thick. Posterior end strongly rostrate. Sculpture I

commarginal. Umbones small and opisthogyrate. Escutcheon well developed. Ligament short, in small, l

oblique resilifer.

I

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114 I
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I Nuculana leonina (Dall, 1896)

Figure 5.7

I Leda leonina Dall, 1896: 2.

N. amiata Dall, 1916: 10, nora. nud. Dall, 1916b: 395.

I L. liogona Dall, 1916: 10, nom. nud.; Dall, 1916b: 396.

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-69 (927 m).

I Description. Shell elongate. Rostrum long, broad (short in small specimens). Sculpture of strong,

widely spaced commarginal ribs, frequently eroded in large specimens. Prodissoconch large, smooth, but

eroded in large specimens. Escutcheon narrow, well demarcated. Periostracum very dehiscent, dark in large

I specimens. Length to 25 ram.

Type Locality and Type Specimens. Sea Lion Rock, Washington, 477 - 559 fathoms; Syntypes,

USNM 107425, ANSP 68138.

I Distribution. Southeast Bering Sea (55 ° N), to San Diego, California (33 ° N) and to Kamchatka in

the western Pacific; in 350 - 2,500 m.

I Literature. Scarlato (1981: 182-183).

I

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I

B

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Figure 5.7. Nuculana leonina:A, exterior of right valve;B, interiorof left valve; C, dorsalview of both valves.

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i 115
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A B I

I

Figure 5,8, Nucufana hamata: A, exterior of right valve; B, dorsal view of both valves. III

I

Nucula_ lm1_u_ta(Carpenter, 1864)

Figure 5.8 1

Leda hamata Carpenter, 1864b: 644; 1866: 210.

Leda hamata limata Datl, 1916: 10, nom. nud.; Dall, 1916b: 397. 1

Material Examined. California, Santa Mafia Basin, Phase II, Sta.R-4 (92 m), PJ-17 (126 m).-- i

Lectotype (see below). I

Description. Shell elongate, with sharp, widely spaced commarginal ribs in some; others almost

smooth. Rostrum very long and narrow, strongly recurved. Periostracum dull to silky. Escutcheon prominent, l

Length to 12 mm. I

Type Locality and Type Specimens. Catalina Island, California, 20 - 60 fathoms; Lectotype, USNM

107420. 1

Distribution. Forrester Island, Alaska (55 ° N) [SBMNH], to Isla Cedros, Baja California [Norte]

(27 ° 55'N), but possibly as far south as Panama [USNM], in 30 - 550 m. Also reported as early as the i

Pliocene in western North American. 1

Literature. E. J. Moore (1983: 22).

Nueulana eonceptionis (Daft, 1896) I

Leda conceptionis Dall, 1896: 2.

Leda gomphoidea Dall, 1916:11, nora. nud; Dall, 1916: 396. i

I

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-63 (930 m), BSS-77 (578

m); Phase II, Sta. R-3 (409 m), PJ-20 (148 m).---Syntypes, USNM 107426 (see below). I

Description. Shell very elongate, thin, compressed, smooth, with a highly varnished, iridescent 1

periostracum. Rostrum narrow. Escutcheon narrow, poorly defined. Length to 30 nun.

I

116 I
!

!

i F_ _=....... i _ -@ "_7 4_,. / _ ._._ ;,. #

A B

,! _--_ :_ ..

i Figure 5.9. Nuculana conceptionis: A, exterior of right valve; B, interior of left valve; C, dorsal view of both valves.

Type Locality and Type Specimens. Pt. Conception, California; Syntypes, USNM 107426, ANSP

68137.

Distribution. Pribitoff Islands, Bering Sea (57 ° N) to off Newport Bay, California (33 ° 30'N) in

148 - 2,300 m.

i Nuculana taphria (Dall, 1896)

i Figure 5.10

Leda taphria Dall, 1896: 70, nom. nov. pro Nucula caelata Hinds, 1843: 99, non Nucula coelata Conrad,

1833 [see ICZN Code Art. 58].

I Material Examined, California, Santa Maria Basin, Phase I, Sta.BSS-21 (49 m); Phase II, R-8

(308 m).

I Description. Shell short, inflated. Sculpture of sharp, heavy commarginal ribs that become obsolete

on posterior slope. Rostrum sharply pointed. Periostracum shiny, iridescent. Escutcheon wide, less clearly

demarcated by radial ridges than in Nuculana penderi (Figure 5.10). Length to 20 mm. Shell subequilateral,

.i inflated, elongate to ovate. Sculpture of strong commarginal ribs or corrugations. Posterior end with a

M pointed rostrum, set off by shallow radial sulcus. Anterior and posterior set of teeth subequal. Pallial sinus

deep.

I Type Locality Type Specimens. Unknown, possibly at

and BMNH.

Distribution. Fort Bragg, California (39.5 ° b0 to Isla Cedros, Baja California [Norte] (28 ° IV)in 10

i - 100 m.Liter Rported ature. asE.earlyJ. Moore as the (1983: Oligocene19-20). in northwest America.

!

:!

I 117
!

!

I

!

I

l

I

I

Figure 5.10. Nuculana taphria: A, exterior of right valve; B, interior of left valve;C,dorsal view of both valves. I '

Nuculana pontonia (DaU, 1890) i

Figure 5.11 l

Leda pontonia Dall, 1890: 257.

Material Examined. California, Santa Mafia Basin, Phase I, Sta.BSS-92 (444 m).--Holotype (see I

below).

Description. Shell thin, with a pointed rostrum. Sculpture of fine rounded commarginal riblets, I i

becoming obsolete on central slope. Escutcheon very wide, deep. Rostrum pointed. Periostracum light olive

to brown, dull to silky. Length to 18 ram.

USNM Type Locality and Type Specimens. Near the Galfipagos Islands, Ecuador, 817 fathoms; Holotype, i96943.

Distribution. San Diego, California (33° N) to the Gulf of Panama (6° N) [USNM] and the Galfipagos

Islands, in 1,150 - 3,000 m. I

Literature. Gooch and Schopf (1972), Rokop (1979).

!

I

1

118 I
I

I

I

I

i

I

I

I

I Figure 5.11. Nuculana pontonia: A, exterior of rightvalve;B,interiorof left valve;C, dorsal view of both valves

i Family Tindariidae Scarlato and Starobogatov, 1971

i Diagnosis. Shell robust, inflated and subequilateral. Periostracum thick, adherent. Sculpture absent,

or of commarginal lirae or riblets. Umbones prominent, prosogyrate. Hinge plate wide and strongly arched,

with a continuous series of taxodont teeth. Ligament opisthodetic and external. Adductor muscle scars

I Pallial line sinus absent, small. Mantle lobes unfused, absent, but subequaL obscure; Byssal gland Siphons

inhalant region of mantle edge with elongate papillae. Foot with divided papillated planar sole. Gill

protobranch, oblique with respect to anterior-posterior axis, with few, widely spaced, thick filaments. Labial

I palps small, with few ridges on inner surface; palp proboscides elongate. Alimentary canal with large type 1 stomach lined with cuticle; three ducts to the digestive diverticula; style-sac conjoined to mid-gut; intestine

looping once to right of stomach; rectum passing through ventricle of heart.

!

Genus Tindaria Bellardi, 1875

.I Tindaria Bellardi, 1875. Type species (M): T. arata Bellardi, 1875. Pliocene, Italy.

Dmgn_is. Shell solid, inflated, ovate. Periostracum adherent. Sculpture commarginal lirae or riblets,

I often minuteobsolete in central . Umbones section. prosogyrate. Ligament opisthodetic Hinge plateandarched external, and with strong. a section Taxodont sunken teethintoin continuous a groove. Siphons series,

absent; mantle with conspicuous papillae bordering incurrent region. Labial palps small. Gills small and

I oblique. Remarks. These solid little shells are difficult to identify, and though the teeth are in a continuous

series, the subumbonal ones may be minute. Named from the Greek proper name Tyndaraeus, a king of

I Sparta, but the gender is feminine.

i 119
!

Tindaria kennerlyi (DaU, 1897) I

Figure 5.12

Malletia (Tindaria ) kennerlyi DaI1, 1897:11. I[

Tindaria dicofania Dall, 1916: 13, nom. nud.; Dall, 1916: 401.

am

T. martiniana Dall, 1916: 13, nora. nud.; Dall, 1916: 401. I

Material Examined. California, Santa Mafia Basin, Phase I, Sta.BSS-78 (762 m).--Holotype (see

below), l i

Description. Shell elongate, subequitateral; posterior end rounded; dorsal margin straighter than in

other species. Sculpture of numerous minute commarginal striae becoming obsolete on ends. Length to 5

mm |

Type Locality and Type Specimens. Off the coast of Washington, 559 fathoms; Holotype, USNM

123497. Distribution. Cape Flattery I , Washington (48 ° N), to San Diego, California (33 ° N) andin the Gulf

of California, in 762 - 2,500 m.

!

!

!

.!

A B !

!

Figure 5.12. Tindaria kennerleyi: A, exterior of left valve; B, interior of right valve.

!

!

!

!

!

120 I
I Family Neilonellidae J. A. Allen, 1978

= Satumiidae J. A. Allen and Hannah, 1987, non Boisduval, 1837

I Diagnosis. Shell aragonitic, homogeneous or crossed-lamellar; interior porcelaneous, rarely

subnacreous. Subequilateral to inequilateral, rather inflated, venerid shaped. Periostracum thin, dull, adherent.

I Sculpture sometimescomma separartedginal. by naAnterior rrow plain and area, posterwithou ior gapes t resabsen ilifer.t.Ligament Hinge plate extewith rnal, taxodont opisthodetic teethtoinamphide two series, tic,

weak. Pallial sinus large. Foot with papillated, planar sole. Siphons present, inhalant and exhalant fused.

I Hpalpypobproboscides ranchial glands narrowabsen andt. Gills protobranch, with many plates. Labial palps large, with many ridges; long. Alimentary canal with type 1 stomach; three ducts leading to digestive

diverticula; style sac not fused to mid-gut; intestine passing through ventricle of heart.

I The fromfamily the Malletiidae may be related in being to thesmaller Nuculanidae, and in lacking but the lack conspicuous of a resilifer gapes,supports and fromits separation. TindariidaeThey in having differ

siphons and a short gap in the dentition under the beaks (except in Austrotindaria). There are three living

I genera water with approximately 35 species. Known from the Jurassic and present in all oceans, especially in deep in soft substrata.

Literature. J. A. Allen (1978: 390-392), Knudsen (1970), Sanders and Allen (1977, 1985).

II

Genus Neilonella Dall, 1881

I Saturnia Mediterranean. Seguenza, 1877, non Schrank, 1802. Type species (M): NucuIa pusio Philippi, 1844. Pliocene,

Neilonella Dall, 1881. Type species (OD): Leda (Neilonella) corpulenta Dall, 188I. Recent, Caribbean.

I Pseudoneilonelta Laghi, 1986, nom. nov. pro Saturnia Seguenza, non Schrank.

I SculptureDiagnos of commarginal is. Shell thick, riblets. inequilateral, Umbones inflated prominent, . Posteri opisthogyrate. or end produced Hinge. Peri plateostracum wide; taxodont thin, adheren teetht.

heavy, continuous or separated by narrow subumbonal area. Ligament opisthodetic, mostly external, portion

I under small beaks siphons.sunken. LabialPallial palps line large;obscure; patp proboscides pallial sinuswide. unclear. Alimentary Mantle canal lobes not withfused, type 1except stomach; in forming intestine2

curving to right.

I The generic level taxonomy within this family is far from settled, and Pseudoneilonella may not be a synonym of Neilonella (T. R. Waller, letter, 3 November 1995).

A very widely distributed deep-water genus, comprising some 30 species. This genus occurs as

I early as the Eocene, and date from the Jurassic. The name is from the Greek diminutive Neilos, the

may

river Nile; the gender is feminine.

!

!

!

!

i 121
!

Neilonella ritteri (Dall, 1916) I

Figure 5.13

Im

Tindaria ritteri Dall, 1916a: 13, nont nud.; 1916b: 401. I

Tindaria californica Dall, 1916a: 13, nom. nud.; 1916b: 401.

II

Material Examined. California, Santa Maria Basin, Phase II, Sta.R-3 (409 m), R-7 (565 m). I

Description. Shell ovate-elongate, robust, inflated; anterior end sharply rounded; posterior end

produced, pointed. Surface smooth, or with weak commarginal striae. Periostracum dark brown. Length to 1

12mm. I

Type Locality and Type Specimens. Off La Jolla, California, 191-293 fathoms; Holotype, USNM

209396. The type specimen of Tindaria californica is ajuvenile of this species. 1

Distribution. Santa Barbara (34.4 ° N) [USNM] to La Jolta (32.7° N) [USNM], California, in 366 -

565 m. I

Family Sareptidae Stoliczka, 1871 ! Diagnosis. Shells inflated, thin, ovate to elongate. Ligament partly internal, in a resilifer. Siphons

present; pallial line with sinus. Adductor muscles subequal. Hypobranchial gland present. Labial palps

large; palp proboscides Foot thick, with divided plantar papillated sole. Gills tranverse, with few I_

narrow.

gill plates. Alimentary canal consisting of large stomach and long, coiled intestine; style-sac and mid-gut

Ill

conjoined. I

Remarks. As pointed out by Maxwell (1988), Sareptidae is the first family-group name available I

for this complex. Thus, if the poorly known, deep-water Sarepta is included here, that must be the family

name. Three subfamilies are present in the eastern Pacific. 1

i

Genus Yoldia M611er, 1842

Yoldia M611er, 1842. Type species (SD ICZN Opinion 769, 1966): Y. hyperborea Torell, 1859, = Nucula I

hyperborea Gould, 1841, ex Lov6n MS. Recent, North Atlantic.

II

Diagnosis. Shell thin to robust, inequilateral, subovate. Posterior end produced, usually gaping. 1

Hinge plate not strong; small taxodont teeth in 2 subequai series. Resilifer large. Pallial sinus deep.

!

!

!

!

Figure 5.13. Neilonella ritteri: A, interior of fight valve; B, exterior of left valve. I

122 I
!

I ¥oldia seminuda Dall, 1871

Figure 5.14

I Nucula arctica Broderip and G. B. Sowerby I, 1829: 359, non J. E. Gray, 1824.

Yoldia seminuda Dall, 1871: 153.

I Yoldia scissurata Dall, 1897: 8, nom. nov. Nucula arctica Browerip and G. B. Sowerby I, non J. E. Gray.

pro

Yoldia ensifera Dall, 1897: 9.

I Yoldia ensifera plena Dall, 1908: 256. YoMia (Cnesterium)strigata Dall, 1909: 104.

Yoldia (Cnesterium) excavata Dall, 1925: 31.

I Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-6 (109 m); Phase II, Sta. PJ9 (169 m).--Holotype (see below).

I Description. Shell compressed, thin, elongate, subequilateral; posterior end with slightly recurved, blunt to slightly pointed rostrum; postero-dorsal keel low to raised. Oblique ribs present on one or more

slopes, widely spaced. Periostracum adherent, shiny, frequently banded with light and dark. Length to 40

| ram.

Type Locality and Type Specimens. St. Paul's Harbor, Kodiak, Alaska; Holotype, USNM 107678.

I Bering Sea Dist(63 ribut° N) ion.to ASanrcticDiegando, nCal orthwestern ifornia (32.7 Pacific. ° N); Beauf in 15or- t375Sea,m.Alaska (71 ° N), St. Lawrence Island,

Literature. Heath (1937: pls. 6, 8), Lubinsky (1980: 21), N. MacGinitie (1959: 154-155), Scarlato

I (1981: 201-202), Stasek (1965).

!

!

!

Figure 5.14. Yoldiaseminuda: A, exterior of left valve;B, interior of right valve; C, dorsalview of both valves.

I

!

i 123
!

Subclass Pteriomorphia Beurlen, 1944 i

Diagnosis. Shell aragonitic, calcitic, or nacreous. Variable in shape, rounded to trapezoidal, usually

inequilateral, equivalve to subequivalve. Periostracum thick, usually hirsute. Hinge plate weak; dentition m

variable, sometimes obsolete. Ligament amphidetic or opisthodefic, external, occasionally with internal

section in a resilifer. Dimyarian or monomyarian. Mantle lobes usually not fused, lacking siphons. Gills

eleutherorhabdic or synaptorhabdic. Foot vestigial or absent. Adult usually byssate. W

Remarks. The subclass is known from the Ordovician and includes a diverse array of bivalves, /

including ark shells, mussels, oysters and scallops, as well as less well-known forms. Although diverse in •

form and adapted to a wide variety of niches, the subclass represents a single phylogenetic unit accepted i

both by paleontologists and malacologists. Groupings of pteriomorphans that excluded the Arcoida were

termed the Dysodonta or Anisomyada. The specialised modification of the mussel species associated with i

deep-water hydrothermal vents displays some important specializations, but it is clearly a mytilid. One I

recent review proposes three major divisions and includes them in the subclass Autobranchia, asfirst delimited

by Soviet researchers. Here I follow a more conservative course and retain the well-known name for the i

subclass. It

The group is notable for the development and variations of shell form and the structure of the i

ligament. There is a strong tendency to lie on one valve, associated with at least a transitional byssate state, •

and for atrophy of the foot. The monomyarian condition, also typical of the subclass, has evolved

independently in several lineages. Other characters are hypertrophy of the lips to form a cover over the

mouth, and the strong development of the mantle margins, which are usually supplied with sensory organs, i

with the inner fold modified to form a wide pallial curtain. This allows wide opening of the valves while HI

maintaining control of access to the pallial chamber. Several genera have developed elaborate projecting i

periostracal structures, particularly the Arcacea. In the Mytilidae, these are secondary, adventitious structures, i

Order Mytiloida F6russac, 1822 i

Diagnosis. Shell inequivalve, usually equilateral and inflated. Periostracum well developed, usually

thick, often with secondary adventitious projecting structures. Umbones anterior, prosogyrate. Sculpture i

absent, or with radial ribs predominating, sometimes divided into distinct regions. Hinge plate usually

i

weak, edentate, occasionally with small dysodont teeth, striations, or tubercles. Ligament opisthodetic, i

alivincular, external, attached to nymph. Anterior adductor muscle small or evanescent, usually heteromyarian, i

rarely monomyarian. Pallial line simple. Mantle lobes not fused, except for exhalant aperture, which may be

m

supplied with a small siphon. Rarely, mantle fusion is more extensive, leaving only a small ventral aperture ,i

and a small siphon. Mantle folds without ocelli. Majority of species byssate in adult, i

Ill

Remarks. Very widely distributed, especially in shallow water, although also present in the deepest,

hadat regions; a few groups have penetrated into brackish and fresh waters. The order contains one living i

superfamily and family with approximately 250 species. The majority are byssally attached epifauna, but II

shallow infauna are also known, and a few species bore into rock or shell.

I

I

!

124 I
!

I Superfamily Mytiloidea Rafinesque, 1815

Diagnosis. Shell equivalve, strongly inequilateral; umbones anterior, prosogyrate. Periostracum

I thick, usually dark colored and adherent, commonly with secondarily formed, setae. Ligament

sparse

opisthodetic, external on pseudonymph. Sculpture absent, or various. Anterior adductor small to minute;

posterior adductor elongate. Hinge plate feeble, edentate, or with small tubercles. Adult usually byssate.

I Remarks. This group comprises the mussels, usually epifaunal, byssally attached species, frequently

forming dense beds on solid substrata in the intertidal zone, but also byssally attached on muddy foreshores.

i Other representatives are nestlers, and one group contains active borers.

i Family Mytilidae Raf'mesque, 1815

Diagnosis. Shell aragonitic and calcitic, with outer layer of simple calcite and an inner layer of

sheet nacre. Strongly inequilateral, thin and inflated. Umbones prosogyrate, prominent, at or near anterior

I thick, usually highly or black, frequently secondarily Sculpture absent,

end. Periostracum colored hirsute.

or mainly radial, frequently in several zones. Hinge plate narrow, usually weak and edentate, or with

crenulations forming dysodont teeth; vertical crenulations or tubercles may also be present. Ligament external,

I alivincular and sunken into and attached with internal opisthodetic, groove to nymph. Rarely ligament a

resilium set into shallow depression. Heteromyarian, with reduced anterior adductor muscle; rarely

monomyarian, with total loss of anterior adductor muscle. Interior of valves nacreous. Pallial line simple,

I feebly impressed. Scars from pedal musculature strongly impressed. Mantle lobes usually not extensively

fused, except to separate the posterior exhalant aperture, which may be siphonate. Rarely with extensive

mantle fusion, leaving small byssal aperture. A siphonal septum projecting from ventral part of exhalant

I opening helps to separate suprabranchial chamber. Labial palps long and narrow. Foot digitiform, with byssal groove. Adult byssate. Alimentary canal with type 3 stomach, with clustered groups of ducts leading

to digestive diverticula; style-sac conjoined to mid-gut; intestine usually looped, usually passing through

I ventricle of heart.

i Modiolus Genus Modiolus Lamarck, 1799 Lamarck, 1799. Type species (T): Mytilus modiolus Linnaeus, 1758. Recent, North Atlantic.

I terminal.Diag Dorsal nosismargin . Shellstraight inequilateral, or curved. elongate Sculpture and oblique, absent ormedially rarely concent inflatedri.cally Umbonstriated. es anteri Periostr or, but acumnot

varnished, often hirsute. Hinge edentate, but small dysodont tubercles may be present near anterior end of

_I ligame Interionrt.nacreo Ligament us andexsternal, ometimes opisthflushed odetic,with frequecolontlyr. Byssate. sunken into groove, attached to narrow resilial ridge.

Remarks. An easily recognized group, commonly called horse mussels, widely distributed both in

I temperate protruding and warm shallow seas. Usually semi-infaunal in sand or mud, with the posterior end of the shell from the substratum.

I

!

!

i 125
!

Modiolus neglectus Soot-Ryen, 1955 I

Figure 5.15

I

Modiolus neglectus Soot-Ryen, 1955: 64. B

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-21 (49 m); Phase II, Sta. R- I

8 ( 90 m), PJ-15 (155 m). 1

Description. Shell quadrangular, very inflated, with produced, flanged posterodorsal margin; anterior

end not strongly produced. Periostracum varnished, with obscure radial striae on central slope; posterior i

slope sharply clef'reed, with hirsute periostracum; setae simple. Length to 130 mm. II

Type Locality and Type Specimens. San Diego, California; Holotype, LACM.

Distribution. Mugu, California (34 ° N) to Outer Gorda Bank, Baja California Sur, Mexico (27° N), 1

i

in 15- 155 m. i

Genus Amygdalum Mfihlfeld, 1811 I

Amygdalum Mtihlfeld, 1811. Type species (M): A. dendricum Miihlfeld, 1811. Recent, Caribbean.

i

Diagnosis. Shell thin, frequently hyaline. Periostracum thin and adherent. Sculpture absent. Hinge I

plate weak. Ligament small, attached to slight resilial ridge.

Remarks. Members of the genus usually live colonially in a nest of byssal threads and adhering 1

particles. The name is derived from the Latin amygdala, an almond; although almond is feminine, this

derived generic name has been treated as neuter. 1

Literature. J. F. Allen (1955), Wilson and Hodgkin (1967). i

I

Amygdalum pallidulum (Dall, 1916) 1

g

Figure 5.16

Modiolus (?politus) pallidulus Dall, 1916a: 18, nont nud.; Dall, 1916b: 404. I

Material Examined. California, Santa Mafia Basin, Phase I, Sta.BSS-22 (99 m); Phase II, Sta. R1 (91 m), PJ-8 (142 m), PJ-16 (130 m). 1

!1

Description. Shell thin, translucent and compressed. Sculpture absent. Periostracum brilliantly

polished, irridescent. Ventral region opaque, white to yellowish, with yellow striations on central and dorsal

slopes. Length to 34 mm. I

IIF

Type Locality and Type Specimens. Off Morro Bay, California; Holotype, USNM 212746.

400 m. Distribution. Trinidad Harbor, California (41 ° N), to Acapulco, Guerrero, Mexico (17° N) in 40 - i

II

Remarks. This species was described by Dall (1916a) as differing from the Caribbean A. politum

(Verrill and Smith, 1880) only in being smaller and in not being as golden-yellow in color. Clearly, their i

relationship should be reevaluated. II

I

I

126 I
I

!

1 A B

I Figure 5.15, Modiolus neglectus: A, exterior of left valve; B, interior of right valve.

I

I

I A B

I Figure 5.16, Amygdatumpallidufum: A, exterior of left valve; B,interior of right valve.

!

i Genus Crenella Brown, 1827 Crenella Brown, 1827. Type species (M): C. elliptica Brown, 1827, = Mytilus decussatus Montagu, 1808.

• Recent, North Atlantic.

,!i Nuculocardia d'Orbigny, 1853. Type species (OD): N. divaricata d'Orbigny, 1853. Recent, Caribbean.

Diagnosis. Shell inequilateral, tumid, equivalve and small. Umbones not prominent, prosogyrate,

I with prodisoconch clearly demarcated. Periostracum thin, adherent. Sculpture of fine radial lirae, divaricating laterally, and some fine commarginal lirae, resulting in a decussate appearance. Hinge plate weak, with one

or more small tubercles under beaks. Ligament opisthodetic, external, but sunken in groove.

!

I

I

i 127
!

Crenella decussata (Montagu, 1808)

Figure 5.17

Mytilus decussams Montagu, 1808: 69. I

Nuculocardia divaricata d'Orbigny, 1842: pl. 27.

Crenella ? inflata Carpenter, 1864:313.

CreneUa yokoyamai Nomura, 1932: 74. 1

Crenella ecuadoriana Pilsbry and Olsson, 1941: 55.

Crenella decussata laticostata Scarlato, 1960: 65. 1m

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-36 (492 m); Phase II, Sta. R4 (92 m), R-8 (90 m) am

Description. Shell ovate, inflated, with conspicuous radial riblets, which may bifurcate ventrally.

Length to 10 mm.

Type Locality and Type Specimens. Off the coast of Scotland; type not found, possibly BMNH. H

i

Distribution. Arctic and circumboreal. Beaufort Sea, Alaska (70 ° N), south through the Gulf of

California and to northern Peru (3.5° S) (Olsson, 1961), and the Galfipagos Islands (1° N) ; in Atlantic from m

North Carolina to the Caribbean and south to the British Isles; south to Japan in northwestern Pacific; in the I

intertidal zone - 492 m. 

Remarks. Attempts to recognize two taxa here, a northern, coarsely sculptured species and a southern II

species with finer, more bifurcating ribs, quickly fall apart. This species-complex would prove an interesting II

topic for more detailed study.

Literature. F. R. Bernard (1979: 24), Lubinsky (1980: 24), E. J. Moore (1983: 71-72), Ockelmann Ii

(1959: 51-52), Olsson (1961: 130), Scarlato (1981: 220-222), Soot-Ryen (1955: 80-81).

Genus Solamen Iredale, 1924 I

Solamen Iredale, 1924. Type species (M): M. rex Iredale, 1924. Recent, Australia.

Megacrenella Habe, 1955. Type species (OD): Crenella (Megacrenella) tamurai Habe, 1955: 26, = C. •

columbiana Dall, 1897. Recent, northeastern Pacific. !1

Diagnosis. Shell larger than Crenella, thin and inflated. Umbones prominent, anterior. Periostracum i

thin and dehiscent. Sculpture of radial bifurcating riblets. Hinge plate very thin, lacking dyssodont teeth. II

Ventral anterior margin vertically crenulate. Ligament long.

!

I

A e l

Figure 5.17. Crenella decussata: A, interior of leftvalve; B, exteriorof left valve. I

128 I
!

I Solamen columbianum (Dall, 1897)

Figure 5.18

I Crenella columbiana Dall, 1897: 4.

Crenella leana Dall, 1897: 4.

I CreneIla Dall, 1902: 559. megas

Crenella rotundata Dall, 1916a: 20, nora. nud.--Dall, 1916b: 406.

I Crenella tamurai Habe, 1955.

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-6 (109 m); Phase 1I, Sta. Ri 1 (98 m),DesR-6cript(100ion.m).--Ho Shelllhighly otype in(see flated, below). oval. Sculpture of very fine radial striae, and minute, irregular

commarginal striae. Length to 25 mm.

i 107630. Type Locality and Type Specimens. Port Orchard, Puget Sound, Washington; Holotype, USNM

Distribution. Bering Sea; Cook Inlet, Alaska (60° N), to Panama Bay (8° N) and east to Siberia and

I northern Japan, in 20 - 500 m.

Literature. Scarlato (1981: 224), Soot-Ryen (1955: 82-83)

I Genus Gregariella Monterosato, 1883

I GregarielIa Monterosato, 1883. Type species (M):Modiolus sulcatus Risso, 1826, non Lamarck, 1805, =

M. barbatellus Cantraine, 1835. Recent, Mediterranean.

I Botulina Dall, 1889. Type species (M): Modiola opifex Say, 1825. Recent, North Atlantic.

Diagnosis. Shell elongate, inflated. Umbones incurved, orthogyrate. Anterior end smooth or with

i commarginal fibs; posterior end with radial riblets, hirsute behind keel. Hinge plate weak, with dysodont teeth. Ligament opisthodetic, external. Inner shell margins crenulate.

!

!

!

!

A 13

!

I Figure 5.18. Solan_n columbianum: A, exteriorof left valve; B, dorsal view of both valves.

i 129
!

Gregariella coarctata (Carpenter, 1857) i

Figure 5.19 

CreneUa coarctata Carpenter, 1857: 123, ex Dunker MS.

Modiolaria denticulata Dall, 1871: 154.

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-6 (109 m). i

Description. Shell subquadrate, inflated. Umbones anterior, inflated. Anterior end with irregular

commarginal ribs; posterior slope with strong radial and weak commarginal ribs, giving it a somewhat •

cancellate appearance. Periostracum thick, adherent, hirsute posteriorly, with compound setae. Length to 23 I

mm.

i

Type Locality and Type Specimens. Mazatlfin, Mexico; Holotype, BMNH (unnumbered). i

Distribution. Monterey, California (37 ° N) throughout the Gulf of California and south to Callao,

Peru (13 °S) and the Gal_ipagos Islands (1°S), in the intertidal zone - 100 m. Usually boring in a calcareous •

substrate or nestling.

Literature. Kleemann (1986b), E. J. Moore (1983: 72), Soot-Ryen (1955: 76- 79).

Order Limoida Waller, 1978 i

_n

Diagnosis. Shell calcitic and aragonitic, subequilateral, equivalve, usually higher than long. B

Compressed to inflated, not pleurothetic. Umbones widely separated by triangular cardinal area. Sculpture

variable, radial riblets predominant, occasionally with imbricated scales. Byssal notch small or absent, n

Monomyarian. Hinge line short and straight, hinge plate not developed, edentate, sometimes with tubercles. i

Ligament with resilium in short, shallow resilifer. I

Remarks. Limids were included as a superfamily associated with the Anomiacea because of their I

monomyarian condition, until it was established that loss of the anterior adductor muscle has occurred

J

independently in several lines of the Pteriomorpha. It is likely that the order Limoida is distantly related to, m

but more ancient than the true oysters, anomiids and pectinids, being known from the Carboniferous. The i

salient anatomical features include the hypertrophy of the mantle edges with the development of long tentacles. i

The foot has rotated some 180°in relation to the visceral mass and shell, a situation that has been considered

analogous to torsion in gastropods. The order contains one superfamily.

i

J

A a |

Figure 5.19. Gregariella coarctam: A, exterior of left valve;B, interior of right valve.

I

,30 |
!

I Superfamfly Limoidea Rafmesque, 1815

I Diagnosis. Shell ovate to subtrigonate, usually oblique. Umbones prominent, separated by triangular

cardinal area. Periostracum thin and dehiscent. Sculpture absent, or of radial ribs or lime. Hinge line straight,

i usually with prolonged into lateral auricles. Hinge plate weak, edentate, or with feeble tubercles. Right valve small byssal notch. Ligament external but deeply sunken into a central resilifer. Monomyarian. Byssate.

I Family Limidae Rafinesque, 1815

I

foliated Diagnosis calcite, and . Shell inneraragonitic cross-lamellar and calcitic; layer. SubequilateraI, outer layer withhigher a distinct thanmicrostructure broad, frequently derivedoblique. from

Periostracum thin, frequently abraded. Umbones prominent, separated by triangular cardinal area. Sculpture

i absent, or of radial riblets or strong radial ribs, frequently with imbricated scales. Hinge line straight, prolonged into lateral auricles, the anterior sometimes reduced or absent. Hinge plate edentate, or, in some foreign

groups, with tubercles, assuming a taxodont appearance. Ligament external, alivincular and sunken in central

triangular resilifer. Monomyarian. Byssate. Foot variable, short to long and slender. Mantle lobes not fused;

I inner fold forming pallial curtain, which may be fused anteriorly; middle fold with long tentacles; outer fold

with ocelli and photoreceptors. Gills filibranch, plicate and synaptorhabdic. Labial palps small. Lips

hypertrophied, covering the mouth with interdigitating or fused folds. Alimentary canal with type 4 stomach,

I with clustered ducts leading to the digestive diverticula; style-sac conjoined to mid-gut; intestine passing

through ventricle of heart.

I Genus Limatula Wood, 1839

I Limatula Wood, 1839. Type species (SD Gray, 1847): Pecten subauriculata Montagu, 1808. Recent,

northeastern Atlantic.

I Diagnosis. Shell thin, fragile, subequilateral, elongate to ovate and inflated. Umbones subcentral, protruding, separated by narrow cardinal area. Periostracum thin and dehiscent. Sculpture of radial striae or

riblets, frequently with a larger central pair. Valves not gaping. Hinge line straight and short; auricles small,

I subequal. Hinge plate weak and edentate. Ligament in small subumbonal resilifer. Byssate.

!

!

!

!

I

I

I 131
!

L/matu/a saturna F. R. Bernard, 1978 I

Figure 5.20

m

Limatula (Limatula) saturna F. R. Bernard, 1978: 71. I

Limatula californica F. R. Bernard, 1988: 227. n

LimatuIa macleani F. R. Bernard, 1988: 227. B

Pecten subauriculatus Montagu, auctt., non Montagu, 1808.

Material Examined. California, Santa Mafia Basin, Phase I, Sta.BSS-42 (100 m); Phase II, Sta. R- i

4 (92 m).

Description. Shell broad, from straight to slightly oblique; ears proportionately larger than those of •

Limatula attenuata. Height to 16 ram.

Remarks. This is the common shallow-water Limatula of California and Puget Sound, previously

assigned to L. subauriculata. The form later named by F. R. Bernard from California, L. californica, cannot i

be distinguished from material from British Columbia in any way I can discern. Limatula macleani was

based on a specimen from deep water with fine sculpture. This species merits comparison with L.

vladivostokensis (Scarlato, 1955) from the western Pacific. i

Distribution. Albatross Bank, Kodiak Island, Alaska (56.5 ° N) [SBMNH], to Cabo San Lucas,

Baja California Sur (22.9° N) [CAS], in 30 - 675 m. n

Literature. Hertlein and Strong (1946a: 68, as Lima subauriculata), i

Order OsteroidaF6russac,1822 I

Diagnosis. Shell almost entirely foliated calcite; shape variable, depending on substratum. Frequently •

strongly inequivalve, usually pleurothetic, either free, byssally attached, or cemented. Shell margin l

occasionally with interlocking processes. Hinge edentate or with strong teeth. Ligament alivincular or

multivincular. Dimyarian or monomyarian. Foot reduced or absent. •

Remarks. The oysters and scallops appear very different, but a number of anatomical and

developmental features point to a shared ancestry, and it is likely that oysters descended from the scalloplike Triassic Pseudomonotidae, or perhaps earlier. Two suborders are represented in the northeastern Pacific. •

Figure 5.20. Limatula saturna: A, exterior of left valve;B, interior of right valve. I

132 I
!

I Superfamily Pectinoidea Rafinesque, 1815

Diagnosis. Shell subequilateral, pleurothetic on right valve. Right valve with byssal notch, which

I be absent in adults, line auficulate, alivincular; resilium

may Hinge straight, Ligament centrally non-fibrous,

laterally fibrous.

i many more Remarks. This very widely distributed superfamily contains approximately 500 living species and extinct species. The evolutionary relationships of a number of groups of living scallops were

analyzed by Waller (1991), and the following treatment follows his groupings as applied to species in the

i northeastern Four living families Pacific. areI alrecognized, so appreciatetwohisofadvice whichandarethat represented of H. H. inDijkstra the northeastern on this superfamily. Pacific.

Literature. Pelseneer (t931), Waller (1972, 1991), Yonge (1973).

!

Family Pectinidae Rafmesque, 1815

I Diagnosis. Shell primarily calcitic, with an outermost prismatic layer on right valve at least in early

stages, a prominent foliated calcite layer and, inside the pallial line, a crossed-lamellar aragonite layer

I (absent in some). Outline orbicular to subtriangular. Pleurothetic on the fight valve, with byssal notch and ctenolium, at least in early growth stages. Hinge line straight, prolonged by auricles. Ligament amphidetic,

alivincular, with a thick triangular resilium having a dark-brown non-fibrous central part and a fibrous

I lateral part. Monomyarian, with large, subcentral posterior adductor muscle. Mantle lobes not fused; inner fold forming a pallial curtain with guard tentacles; middle fold with tentacles and ocelli. Labial palps small.

Lips hypertrophied. Ctenidia filibranch, eleutherorhabdic. Alimentary canal with type 4 stomach; style sac

I conjoined to mid-gut; intestine passing through ventricle of heart. Collectively known as scallops, the family contains brightly colored shells that have received much

attention from collectors because of their beauty, and from paleontologists due to their importance in Tertiary

I and Quaternary marine biostratigraphic correlation. This very large family arose in the Triassic and includes at least 300 living species in 50 genera and subgenera, cosmopolitan in distribution and extending from

intertidal to hadal zones. The generic name Pecten changes stem in forming the family name Pectinidae.

I The of scallops is difficult, and systematists do not on how to assign species to

taxonomy yet agree

genera and subfamilies. In some cases, the identification of species is complicated by the existence of

numerous intermediate forms, particularly in the genus Chlamys, which appears to be in a period of active

I speciation. There is common agreement that several ancestral stocks are involved, and we are witnessing

convergent evolution. This makes minor features, such as shell microsculpture, important diagnostic criteria,

whereas shell shape and gross ornamentation may not be as important. Even such a dramatic adaptation as

I cementation to the substratum has occurred independently in several unrelated groups. A full appreciation of the systematic arrangement can only be obtained by review of the world Cenozoic fossil record, so a

conservative arrangement, using anatomical and conchological criteria, is adopted here.

I The is characterized several structures at the antero-dorsal The notch is family by margin. byssal

a

deep indentation in the right auricle. The byssal sinus is a shallower indentation in the left auricle. The

byssal fasciole is a track left by the developing byssal notch. The ctenolium is a comb-like series of denticles

I along the ventral margin of the byssal notch, which the strands of the byssus and mechanically

separates

strengthens byssal attachment and prevents rotation. Whereas juveniles are usually byssally attached, adults

are commonly free-living; some give up their byssal attachment and become cemented to the substratum.

I

!

I 133
!

The anatomy of scallops is rather conservative and uniform. The most characteristic feature is the I

hypertrophy of the posterior adductor muscle, which occupies a subcentral position, and the disappearance

of the anterior muscle. While the labial palps are small, the lips are hypertrophied, forming a cover with il

many pores over the mouth. This structure may help to retain the mucous food string in the mouth. The I

anatomy of the gill and alimentary canal suggest the family is primarily adapted to clear water and fine food

particles.

All species are epifaunal, bysally attached or lying free on the right valve; one northeastern Pacific II

genus is permanently cemented. Many species are notable for their energetic but rather inaccurate swimming

by clapping the valves vigorously together, propelled by the water jet expelled on each side below the bases 1

of the auricles. Widely distributed from the intertidal zone to abyssal depths. Frequently locally abundant I

and coveting extensive areas, several species support extensive commercial exploitation.

I1

Genus Chlamys Rrding, 1798 I

Chlamys Rrding, 1798. Type species (SD Herrmannsen, 1847): Chlamys cinnabarina Rrding, 1798, = •

Ostrea isIandica Gmelin, 1791. Recent, North Atlantic. I

Diagnosis. Shell subequivalve, higher than long, with anterior auricles larger than posterior. Byssal roll

notch moderately deep to very deep, with persistent ctenolium. Sculpture of radial ribs, increasing in number 1

by branching or intercalation, and commonly with scales or spines.

Remarks. Members of this genus conform to a conservative pattern, but with variable development •

of external sculpture. The relationships among the species, and the degree of morphological variation, have I

not been resolved. Internal shell characters, such as pallial scars, hinge structures, and accessory scars, are

difficult to see, so identification is based on external sculpture and color. Microsculpture details also offer am

valuable distinguishing criteria. I

Chlamys hastata (G. B. Sowerby II, 1842) I

m

Figure 5.21

Pecten hastatus G. B. Sowerby II, 1842: 72. I

Illl

Pecten comatus Valenciennes, 1846: pl. 18, non Miinster, in Goldfuss, 1833

Pecten rastellium Valenciennes, 1846: pl. 19, non Lamarck, 1819. •

Pecten hericius Gould, 1850: 345.

Pecten hericeus, auctt., nora. null.

I

Pecten altiplicatus Conrad, 1857: 191. I

Pecten (Chlamys) lawsoni Arnold, 1906:117.

Pecten islandicus pugetensis Oldroyd, 1920:136. 1

Pecten newcombi Oldroyd, 1938: [2], nomen nudum.

ChIamys hastata ellisi Hertlein and Grant, 1972: 190. I1

Ill Material Examined. California, Santa Mafia Basin, Phase I, Sta.BSS-6 (109 m).

Description. Left valve with 8-20 primary radial ribs with strong, imbricated spines. Interspaces •

with 1-10 coarsely scaled, intercalary riblets and fine, striose microsculpture. Anterior auricle with many I

strongly imbricated radial ribs. Right valve with 12-24 rounded primary ribs, similar to left valve, but with

only 3-4 intercalary riblets. Anterior auricle large, with 7-10 imbricated radial riblets. External color variable, lm

usually pink to yellow, often radially or concentrically streaked. Height to 80 mm. I

,34 |
!

!

!

!

!

!

m A B

!

Figure 5.21. Chlamys hastata: A, exterior of right valve; B, exterior of left valve.

!

I Type Locality and Type Specimens. San Diego, California; Holotype, BMNH (unnumbered)

Distribution. Kenai Peninsula, Alaska (59.5 ° N), to San Diego, California (33 ° N), in the intertidal

I zone - 160 m.

Remarks. A very variable species, many with short to nearly absent spines and drab coloration are

i found Columbia, throughout Washington the range, and California usually onthatmuddy have asubstrates. pronouncedSpecimens reticulatedfrommicrosculpture protected wawere ters of named BritishC.

pugetensis. Individuals with developed spines and fine coloration are from hard substrates and usually are

i covered Some with spo workers nge. may chose to recognize two geographic subspecies, C. hastata hericia (Gould, 1850)

from the Gulf of Alaska to Puget Sound and S. h. hastata (G. B. Sowerby II, 1843) from the Washington to

I San ribs Diego. are moreThesubdued lattr has in thefasciculated northern subspecies. ribs in the right valve and ribs of three orders in the left valve. The

Literature. Bloom (1975), Buck (1988), C. A. Cooke (1988), Grau (1959: 85-91), Gregg (1938),

I Hodgson and N. J. Bourne (1988), E. J. Moore (1984: 22-24), R. G. B. Reid and Rauchert (1970), Rombouts (1991: 12-13), Stasek (1963: 198), Strathmann (1987: 331-332), Vassallo (1973), Waller (1991: 21).

I Leptopecten Verrill,

Genus 1897

Leptopecten Verrill, 1897. Type species (OD): Pecten monotimeris Conrad, 1837, = P. latiauritus Conrad,

I 1837. Recent, northeastern Pacific. Diagnosis. Shell thin, forwardly slanting, of low convexity; left valve more convex than right. Ribs

simple, non-branching, low, rounded. Posterior auricles larger than anterior. Byssal notch deep; ctenolium

I with prominent teeth.

I 135
!

Leptopecten latiauratus (Conrad, 1837) i

Figure 5.22

Pecten latiauratus Conrad, 1837: 238. i

Pecten Iatiauritus, auctt., nora. null.

Pecten monotimeris Conrad, 1837:238 (f'n-streviser: Bernard, 1983). 1

Pecten tunica R. A. Philippi, 1844: 100.

Pecten latiauritusfucicolus Dall, 1898: 710. 1

I

Pecten (Chlamys) latiauritus fragilis Arnold, 1903:112, non P.fragilis Defrance, 1825.

Pecten (Chlamys) latiauritus bellilamellatus Arnold, 1906: 108. i

Pecten (Chlamys ) latiauritus cerritensis Arnold, 1906: 129. i

Pecten (Chlamys) latiauritus delosi Arnold, 1906: 130.

I

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS- 1

Description. The thin, almost hyaline and oblique valves, with 9-20 shallow radial corrugations,

distinguish this species. The interspaces have fine commarginal lamellae that carry over the ribs; ribs may •

have a central groove. Auricles broad, but short. Exterior color usually brown-grey, rarely orange, maculated I

with white or brown chevron-shaped marks, rarely entirely white. Height to 50 mm.

Type Locality and Type Specimens. San Diego, California; Holotype, ANSP. 1

m

Distribution. Point Reyes, California (38° N) to Cabo San Lucas, Baja California Sur (23 ° N) and

throughout the Gulf of California, in intertidal pools to 250 m. I

Literature. G. R. Clark (1971), Coe (1932: 60-62, 1945), Grau (1959:107-113), Hadertie and D.P. 1

Abbott (1980: 366), Hertlein and Strong (1946a: 59-60), McPeake and Glantz (1982), E. J. Moore (1984:

43 -44), Rombouts (1991: 26). II

B

!

!

!

!

A B i

Figure 5.22. Leptopecten latiauratus: A, exterior of right valve;B, exterior of left valve, i

136 I
I

I Genus Delectopecten Stewart, 1930

Delectopecten Stewart, I930. Type species (OD): Pecten (Pseudamussium) vancouverensis Whiteaves,

I 1893. Recent, northeastern Pacific.

Diagnosis. Shell thin, biconvex, subequivalve. Surface not sculptured, or with commarginal and

I radial concentric striaallye; intersecti undulated. ons Posterior frequentlyauricles with small, mergedimbrica into rest ted ofspines shell.or pustules. Umbonal region may be

I Delectopecten vancouverensis (Whiteaves, 1893)

Figure 5.23

I Pecten (Pseudamussium) vancouverensis Whiteaves,

1893: 133.

Pecten randolphi Dall, 1897: 86.

I Pecten whiteavesi Orcutt, 1915:183 [?ex Dall MS], nom. nud.

Pecten (Pseudamusium) randolphi tillamookensis Arnold, 1906:139.

Pecten (Pseudamusum) arces Dall, 1913: 592.

I Cyclopecten argenteus F. R. Bernard, 1978: 66.

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-13 (197 m), BSS-20 (396

I m); Phase II Sta. R-9 (410 m).

Description. Shell colorless, thin and translucent, often with an oily, iridescent sheen. Left valve

I mminute ore convex than right. Valves weakly undulated, more pronounced on umbones. Both valves with numerous radial and equidistant commarginal lirae, and with short, imbricated spines at the intersections,

more conspicuous towards anterior and posterior margins. Some specimens almost smooth. Auricles large;

anterior auricle of right valve with 4-9 imbricated radial riblets. Byssal notch deep, rounded. Height to 45

|

I

I

I

I

I

I " B

I Figure 5.23. Detectopecten vancouverensis: A, exteriorof right valve;B, exterior of left valve.

i. 137
!

Type Locality and Type Specimens. Foward Inlet, Quatsino Sound, Vancouver Island, British I

Columbia, 10-20 fathoms; Holotype not found.

Distribution. Bristol Bay, Alaska (58 ° N) into the Gulf of Alaska to Prince William Sound, Alaska I

(61°N), south to Isla Cedros (28 ° N) and Isla San Benitos (28 ° N) Baja Calif. [Norte], and off Guaymas, I

Sonora, Mexico (28°N), in 45 - 2,000 m.

Remarks. A byssate nestler on mud, usually associated with large silicious sponges and sometimes II

with large crustaceans.

Literature. Grau (1959: 40-42, 44-47), E. J. Moore (1984: 16-18), Okutani et al. (1989: 72), I

Rombouts (1991: 76, 78), Scarlato (1981: 260-261). •

Subclass Heterodonta I

Family Lucinidae Fleming, 1828 I

Diagnosis. Shell aragonitic, with prismatic outer, cross-lamellar middle, andcomplex cross-lame[lax l

inner layers. Outline usually rounded, subequaliteral, equivalve. Umbones central. Sculpture absent, or of II

commarginaI or radialribs. Periostracum inconspicuous, dehiscent. Lunule clearly impressed, subsymetrical.

II

Ligament opisthodefic, parivincular, external, but usually deeply sunken into groove. Hinge plate weak;

dentition variable, usually with 3 cardinal teeth in each valve; lateral teeth weak or absent, rarely duplicated 1

in left valve. Pallial sinus absent. Dimyarian; anterior adductor muscle scar elongate. Mantle lobes with i

small fusion setting off posterior exhalant aperture, sometimes prolonged with an invaginable pseudosiphonal

tube. Gills synaptorhabdic and homorhabdic, thick; outer demibranch lost. Foot vermiform, with distal i

bulb. Labial pulps small. Alimentary canal with type 4 stomach; ducts to the digestive diverticula clustered

into 2 or 3 groups; intestine passing through ventricle of heart. dllll

Remarks. The family is found in fine sediments of high organic contents and is deeply infaunal. It 1

probably represents a monophelytic and widely distributed lineage, comprising a rather complex assemblange

w

of species sharing similar anatomical structures. The group is divided into four living subfamilies, two iim

present in the northeastern Pacific. I

Genus Parvilucina Dull, 1901 I

II Parvilucina Dull, 1901. Type species (OD): Lucina tenuiscuIpta Carpenter, 1864, =Parvilucina mazatlanica

tenuisculpta (Carpenter, 1864). Recent, California.

Diagnosis. Shell strongly inflated, small. Sculpture strongest on central slope, consisting of f'me I

commarginal lirae and radial striae. Ligament marginal. Hinge plate weak. Inner ventral shell margin finely

crenulate. I

!

138 I
!

I Parvilucina tenuiscuipta (Carpenter, 1864)

Figure 5.24

I

Lucina tenuisculpta Carpenter, 1864a: 642; 1865f: 57.

I Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-79 (98 m); Phase II, R-2 (161 m), R-4 (92 m).--Holotype (see below).

Description. Shell subcircular, beaks low, hinge line slightly curved; sculpture of fine commarginal

I striae weak overlain by weak radial ribs, almost obsolete in material; surface etched in

some deeply many

specimens. Inner ventral margin weakly crenulate. Lunule shallow, narrow, in both valves. Hinge narrow,

evenly arcuate; lateral teeth weak. Length to 13 mm.

I Type Locality and Type Specimens. Vancouver Island, British Columbia; Holotype, USNM 5244.

Distribution. Kodiak Island (57.3 ° N) [CAS] and Galena Bay, Prince William Sound, Alaska (60.9°

I N) organic [LACM], contentot,Islwhere a Cedros, it mayBaoccur ja California in dense[Norte] colonies. (28.2Recorded ° N), in theas early subtidai as the zoneMiocene to 300 m,ininCalifornia. mud of high

Literature. Felbeck et al. (1981), U. S. Grant and Gale (1931: 288 -289 ), Hickman (1994:53- 55),

I G.F. Jones and Thompson (1984), E. J. Moore (1988: 14-15), R. G. B. Reid and Brand (1986).

Genus Lucinoma Dall, 1901

I Lucinoma Dall, 1901. Type species (OD): Lucinafilosa Stimpson, 1851. Recent, New England.

i commarginal Diagnosis. lamelliform Shell large, riblets, lenticular and f'meto commarginal subcircular; posteri lirae.orUmbones end truncdepressed. ate. SculpturePeriostracum of regularlythinspaced and

adherent. Lunule lanceolate. Hinge plate narrow, with two teeth in each valve. Anterior adductor muscle

i scar elongate and divergent. Ventral inner shell margin smooth.

_!_.. :...i_, • .: : -; ..... .."

'::!:ii:

I

Figure 5.24. Parvilucina tenuisculpta:A, exteriorof left valve; B,interiorof right valve.

I

. 139
I

Lucinoma annulatus (Reeve, 1850) I

Figure 5.25

II

Lucina annuIata Reeve, 1850: sp. 17. 1

Lucinoma densilineata Dall, 1916: 27, nom. nud.

Lucinoma annuIata densilineata Dall, 1919: 249. I

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-21 (49 m); Phase II, Sta. R4 (92 m).--Holotype (see below). 1w

Description. Shell orbicular, only moderately inflated. Sculpture of sharp, widely spaced

commarginal lamellae. Periostracum thin, light to dark tan, dehiscent. Lunule lanceolate and deeply impressed. 1

Length to 82 mm. 1

Type Locality and Type Specimens. California; Hototype, BMNH 1963121,

Distribution. Kodiak Island and Prince William Sound, Alaska (60° N), to the Gulf of California as I_

far north as Guaymas, Sonora, Mexico (28 ° N), in 25 to 750 m.

Literature. Distel and Felbeck (1987), Felbeck et aI. (1981), E. Moore (1988: 17).

'l

Family Thyasiridae Dall, 1900 [1895]

Diagnosis. Shell aragonitic, with composite prismatic outer, cross-lameUar middle, and complex I

cross-lamellar inner layers. Outline rounded to subtrigonal or subquadrangular, frequently oblique. Equivalve,

with small, subcentral prosogyrate umbones. Periostracum inconspicuous, adherent. Sculpture absent, or of •

commarginal lirae, frequently with radial sulci or folds demarcating the posterior slope. Lunule broad and II

clearly demarcated. Ligament opisthodetic, parivincular, external but deeply sunken into groove. Hinge

plate weak, edentate, or with tubercles or striations. Pallial line entire. Dimyarian; posterior adductor scar •

rounded to elongate; anterior scar extremely elongate and merged with the pallial line. Mantle lobes with II

small fusion setting off the posterior exhalant aperture. Gills synaptorhabdic and homorhabdic, filaments

thickened. Foot long and vermiform, with distalsecretory bulb. Labial palps small. Alimentary canal with type II

4 stomach; ducts to the digestive diverticula collected into 2-3 clusters; intestine piercing ventricle of heart. 1

!

I

!

"?.i_:i:!_._,;:_, : __ _,

Figure 5.25. Lucinoma annulatus: A, exteriorof left valve; B, interiorof rightvalve. I

140 '1
!

I Genus Thyasira Lamarck, 1818, ex Leach MS

Thyasira Lamarck, 1818, ex l_e.achMS. Type species (OD):Amphidesmaflexuosa Lamarck, 1818, = Tellina

I flexuosa Montagu, 1803. Recent, Europe.

Axinus Sowerby, 1821.Type species (OD): Axinus angulatus J. Sowerby, 1821, = TeIIinaflexuosa Montagu,

1803.

I Cryptodon Turton, 1827. Type species (OD): Axinus amplicatus J. Sowerby, 1821, = Tellina flexuosa

Montage, 1803.

I Diagnosis. Shell subcircular to trigonate, frequently oblique. Equivalve, usually higher than long.

Sculpture feeble, commarginal. Posterior set offby one or more strong radial furrows. Umbones prosogyrate.

Lunule indistinct; escutcheon long and narrow. Hinge plate weak, edentate, frequently tuberculate and with

I minute pseudocardinal in the left valve.

Remarks. The genus is well represented in oxygen poor environments with free hydrogen sulfide.

The majority of species are variable in shape, leading to numerous needless synonyms. There is direct

I development young a protective capsule emergence as a juvenile, eggs are large

of the in and benthic The

and invested with a sticky membrane.

I" Thyasira flexuosa (Montagu, 1803)

Figure 5.26

I Tellina flexuosa Montagu, 1803: 72.

Lucina sinuata Lamarck, 1818: 543.

I Axinus angulatus J. Sowerby, 1821: 11.

Axinus unicarinatus Nyst, 1835: 6.

I Ptychina biplicata Philippi, 1836: 15.

Lucina gouldii Philippi, 1845: 74.

i Axinus flexuosa sarsii Philippi, rotunda1845: Jeffreys, 91. 1881:701.

Axinusflexuosa polygona Jeffreys, 1882: 248.

I barbarensis 1890: 261. Cryptodon Dall,

Thyasira cygnus Dall, 1916: 26, nora. nud.; I916a: 409.

I Material Examined. Santa Mafia Phase Sta.BSS-22 Phase R-7

California, Basin, I, (99 m), II,

(565 m).

i prominent, Description. Shell small, milk white, highly inflated; periostracum inconspicuous. Umbones slightly prosogyrate. Sculpture of commarginal striae, posterior end separated by radial sulcus,

deeper in adults. Hinge plate feeble, broad, with obscure cardinal tubercle in left valve. Length to 12 mm.

: Type Locality and Type Specimens. Types not found, possibly at BMNH.

!

!

"I 141
I

I

I

Figure 5.26. Thyasiraflexuousa: A, exteriorof right valve;B, details of hinge,left valve lower, rightvalve above; I

C, dorsal view of both valves. l

I Distribution. Circumboreal and Panarctic. In west American from the Beaufort Sea (71°N) and

Chukchi Sea (65 ° N), Alaska, to San Pedro, California (36° N), and to the Gulf of California; south to North I

Africa in the eastern Atlantic, to Virginia in the western Atlantic, and to Hokkaido, Japan, in the western 1

Pacific, in 20 to 3,000 m, in f'me mud. g

Literature. Bernard (1972: 35-36, 1979), Bresciani and Ockelmann (1966), Dando and Southward IN

(1986), Le Pennec etal. (1988), L6pez and Mejuto (1987), Lubinsky (1980: 38), N. MacGinitie (1959: 171- 1

172), E. Moore (1988: 24), Ockelmann (1958: 100-110, 1961), Scarlato (1981: 310-312), Tebble (1966:

79), Theroux and Wigley (1983: 27-28). n

Axinodon Venill and Bush, 1898

Axinodon Verrill and Bush, 1898. Type species (OD): Axinodon eIlipticus Verrilt and Bush, 1898. Recent, n

northwestern Atlantic. m

Tomburchus Harry, 1969. Type species (OD): Aligena redondoensis T. Burch, 1941. Recent, California. n

Diagnosis. Shell ovate, rather inflated, longer anteriorly. Posterior slope not set off by radial sulcus.

Umbones depressed, prosogyrate. Ligament slightly sunken, attached to nymph. Lunule absent; escutcheon lad

well impressed. Hinge plate feeble, with central tubercle in the left valve, smaller in the right valve, m

Remarks. The genus is widely distributed in shallow to deep water and contains thyasirids with no

strong radial sulcus se_ing off the posterior slope, m

I

I

I

I

142 "'1
!

I Axinodon redondoensis (T. Burch, 1941)

Figure 5.27

I Aligena redondoensis T. Butch, 1941: 50.

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-22 (99 m); Phase II, Sta. PJI 7 (123 m).

Description. Shell minute and inflated. Sculpture absent. Periostracum thin, with patches of adherent

I ferruginous absent; escutcoat cheoinng.well Umbones defined.depressed, Hinge plateprosogyr narrow, ate.withPosteri central or entubercles, d not setlarge off byin radial the leftsulcus. valve Lunuleegth

to 3 mm.

I Type Locality and Type Specimens. Redondo Beach, California.

Distribution. Cape Foulweather, Oregon (45° N),to Redondo Beach, California (34°N) in 120 - 200 m.

I Genus Axinopsida Keen and Chavan, in Chavan, 1951

Axinopsis G. O. Sars, 1878, non Tate, 1868. Type species (OD): Axinopsis orbiculata G. O. Sars, I878, =

I_ Cryptodon suborbicularis A. Adams, 1862. Recent, North Sea.

I[ Axinosida Keen and Chavan, in Chavan, 1951, nom. nov. pro Axinopsis G. O. Sars, 1878, non Tate, 1868. I

I Diagnosis. Shell thin, pellucid, discoid, marginally compressed, but centrally tumid, subequilateral. Lunule margins concave. Hinge plate weak; right valve with recurved projecting pseudocardinal denticle.

I

I

I

I

I

I

I_ Figure 5,27. Axinodon redondoensis: A, exterior of left valve; B,interior of right valve.

I

I

..: 143
l :

i

Axinopsida suborbicularis (A. Adams, 1862) I

Figure 5.28

Cryptodon (Clausina) suborbicularis A. Adams, 1862: 227. II

Cryptodon serricatus Carpenter, 1864a: 643. II

Axinopsida viridis Dall, 1901:819. 1

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-34 (492 m); Phase II, Sta. R- i

3 (409 m), PJ-14 (134 m), PJ-16 (130 m). i

Description. Shell compressed, lenticular; periostracum silky yellow to green. Umbones prominent;

lunule feeble. Right valve with strong central tooth. Length to 8 mm. i

Type Locality and Type Specimens. North Atlantic, types not found, possibly at BMNH. i

Distribution. Circumboral and panarctic. Point Barrow, Alaska (71 ° N) to Isla Cedros, Baja

California Norte (28 ° N), in the western Pacific from Kamchatka Peninsula to northern Japan, and in the i

western Atlantic from Labrador and Baff'm Island, in the low intertidal zone to 275 m, in mud.

Remarks. This highly plastic species has caused difficulties for west American workers. Axinopsis

viridis was through to be proportionately longer than A. serricata, but names for similar pairs of high and 'l

long specimens have been proposed in Japan and the in the North Atlantic. The earliest name for North i

Pacific material appears to be A. suborbicularis (A. Adams, 1862), from Japan, a variable species, also

known as A. subquadratus (A. Adams, 1862), which I believe to be identical. Review of large series of 1

specimens throughout the range reveal no pattern in the outline, except the elongate form appears more

i

frequent in very fine sediment. It is preferable to use the senior synonym from northern Japan. At least in the

eastern Pacific, southern specimens are smaller than northern material. I

Literature. Bernard (1979: 32-33), Lubinsky (1980: 37), N. MacGinitie (1959: 172), E. Moore

I

(1988: 25-26), Ockelmann (1958:111-113), Scarlato (1981: 313-315), Theroux and Wigley (1983: 26). I

!

,!

!

I

,,!

|

Figure 5.2,8. Axinopsida suborbicularis: A, exterior of left valve; B,interior of right valve.

i

t44 I"I
I

I Genus Adontorhina Berry, 1947

Adontorhina Berry, 1947. Type species (OD): Adontorhina cyclia Berry, 1947. Pleistocene - Recent,

I California.

Diagnosis. Shell thin and suborbicular, compressed to inflated. Umbones prominent and prosogyrate.

Sculpture absent, except for commarginal growth lines. Lunule margin concave. Hinge plate strong with

I obscure and variable ridges or tubercles on reflected Iunule and escutcheon margins. Ligament internal.

Remarks. The genus is often confounded with specimens of Axinopsida, with which it frequently

occurs, but it is readily separated by the absence of a cardinal tooth, and from Thysira by the absence of a

I posterior sulcus. The external appearance is also much like Axinulus and Leptaxinus, but the peculiar

interlocking granulations of the hinge of Adontorhina are distinctive.

I Adontorhina cyclia Berry, 1947

Figure 5.29

I Adontorhina cyclia Berry, 1947: 260.

I' m); PhaseMate II Sta. rial PJ-1 Exam(98ined. m), CPJ-4alifo(393 rnia, m).--Holotype Santa Maria Basin, (see below). Phase I, Sta.BSS-36 (492 m), BSS-50 (591

Description. Shell suborbicular and thin. Sculpture absent. Lunule and escutcheon obscure. Hinge

I plate edentate, but with posterior and anterior tuberosities that may be granulate. Length to 3 ram.

Type Locality and Type Specimens. San Pedro, California (Pleistocene); Holotype, CAS 61460.

Distribution. Kasitsna Bay, Alaska (54° N), to San Pedro, California (34° N), in 12 to 3,000 m, in

i sand and mud.

Literature. Jones (1965), Jones and Thompson (1986), E. Moore (1988: 25), Scott (1986).

!

|

,

I.

I

.I

I Figure 5.29. Adontorhina cyclia: A, exterior of right valve; B, interior of fight valve; C, dorsal view of both

valves.

|'

i_ 145
|

Superfamily Carditoidea Fleming, 1828 I

Diagnosis. Shell thick and inflated, usually inequilateral. Umbones prominent. Periostracum thick, 1

generally hirsute. Ligament external, opisthodetic, parivincular, on a strong nymph. Hinge plate wide, arched. 1

At least 2 subequal cardinal teethpresent ineach valve; lateralteeth remote, usually tuberculate, occasionally

absent. Lunule small anddeep; escutcheon obscure.

Remarks. The superfamily dates from the Devonian and includes two living families of thick, I

generally radially ribbed shells, with a particularly strong hinge plate and a uniform dentition pattern. Shallow

infauna, generally byssate. Most species brood their young. One family is represented in the northeastern •

Pacific. Ii

Family Carditidae Fleming, 1828 !

Diagnosis. Shell aragonitic, with cross-lametlar outer and complex cross-lamellar inner layers.

Solid, rounded to trapezoidal, equivalve. Sculpture of strong radial ribs. Lunule small and deep. Umbones _m

prominent, prosogyrate. Periostracum often hirsute. Hinge plate wide; left valve with 2 cardinal teeth; right I

valve with 3 cardinal teeth. Lateral teeth weak or absent. Ligament external, opisthodetic and parivincular, n

with small resilium. Dimyarian. Pallial line entire. Mantle lobes not fused, except for small posterior exhalant

aperture. Siphons absent. Gills synaptorhabdic, homorhabdic. Labial palps small. Foot wedge shaped; byssal '1

groove marked. Alimentary canal with type 4 stomach; ducts to the digestive diverticula concentrated into

3-4 groups; style-sac joined to mid-gut; intestine usually passing through ventricle of heart.

I

Remarks. The sole family of bivalves to demonstrate sexual dimorphism associated with brooding. 1

Two genera have developed a special incubatory chamber in the shell, but the majority of species brood in

the pallial chamber. All representatives are shallow infauna, particularly of warm and tropical seas. !

Genus Cyclocardia Conrad, 1867

Cyclocardia Conrad, 1867. Type species (SD Stoliczka, 1871): Cardita boreal& Conrad, 1831. Recent, 1

northwestern Atlantic.

Ill

Arcturus Gray, 1839, ex Humphrey MS, non Berthold, in Latreille, 1827. Type species (M): Cardita borealis •

Conrad, 1831. 1

Diagnosis. Shell trigonal to cordifoma, thick. Periostracum thick, hirsute in many, polished in some. I

Sculpture of strong radial ribs and commarginal lirae. Umbones small. Hinge plate wide and short. Two 1

oblique cardinal teeth present in left valve; anterior cardinal of right valve obsolete.

Cyclocardia ventricosa (Gould, 1850) I

I

Figure 5.30

Cardita ventricosa Gould, 1850: 276. I

Venericardia (Cyclocardia) stearnsii Dall, 1903: 225. II

Cardita ventricosa redondoensis T. Burch, in J. Burch, ex J. Burch MS: 1944: 14. l

Cardita (Cyclocardia) ventricosa montereyensis Smith and Gordon, 1948: 172.

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-59 (216 m), BSS-95 (198 I

m); Phase 11,Sta. PJ-7 (123 m), PJ-21 (143 m).--Syntypes (see below).

|

146 (I
!

!

!

1

I |

!

!

Figure 5.30. Cyctocardia ventricosa: A, exterior of left valve;B, interior of right valve.

I

I radial ribs, Descbutripless tion.prominent Oval to trigonal, than thosethick, of C.thicker baylei;than ribs not C. barbarensis becoming .obsolete Sculptureon anterior of low, broad, slopes, nodose, as in C.

barbarensis. Periostracum light to dark brown, densely hirsute with radially arranged setae. Hinge plate

I wide, teethTypeheavy. Locality Lunuleandsmall TypebutSpecimens. clearly defined. Puget Length Sound, toWashington; 15 mm. Syntypes, USNM 3373.

Distribution. Galena Bay (61° N) and Cook Inlet (60° N) Alaska, to Punta Rompiente, Baja California

I (28°N), in 20 - 260 m.

Literature. Coan (1977: 380-382), Jones (1963), Popov (1983: 48), Stasek (1962, 1963: 199),

i Yonge (1969).

Cyclocardia barbarensis (Stearns, 1890)

I Figure 5.31

Venericardia barbarensis Steams, 1890: 214.

i Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-89 (471 m); Phase II, Sta. R9 (410 m).--Lectotype (see below).

Description. Shell rounded, thin, relatively compressed. Sculpture of low radial ribs, becoming obsolete around anterior, posterior and vental edges. Periostracum dark brown, fibrous, with few, small

setae. Umbones small, prosogyrate. Hinge plate narrow; teeth strong. Lunule poorly defined. Length to 15

| mm.

Type Locality and Type Spec_ens. Off Santa Rosa Island, California, 276 fathoms; Lectotype,

USNM 104045.

i Distribution. Santa Barbara Island, California (34 ° N), to Santa Rosa Island, California (34 ° N) in

350 - 2,211 m.

i Literature. Coan (1977: 376-377), Jones (1963).

I47
!

!

• |

_._._:_..'5 .),. ":...... :)_ •

IN

'. ....... .,:.. ,_

I

Figure 5.31. Cyclocardia barbarensis: A, exterior of left valve; B, interior of right valve.

!

Superfamily Chamoidea Lamarck, 1809 m

IIE

Diagnosis. Shell thick, aragonitic, occasionally with calcitic outer layer. Strongly inequilateral and

inequivalve, cemented at least at one stage to the substrate by the right or left valve. Usually distorted and I

idiomorphic. Umbones prosogyrate, becoming submerged in shell. • Sculpture prominent, but frequently 1

eroded, consisting of commarginal and radial frills or spines, often different in each valve. Ligament external,

parivincular and opisthodetic, set on a heavy nymph. Hinge plate heavy, generally thickened by obscure and tim

ponderous tubercles and corresponding pits. •

I

Ill

Family

Chamidae Blainville, 1825 1

Diagnosis. Shell thick, aragonitic, with cross-lamellar outer and complex cross-lamellar inner layer,

occasionally with an additional external calcitic layer. Inequilateral, usually distorted and idiomorphic. I[

Strongly inequivalve, with cupped attached and lid-like free valve. Cemented to substrate at least during

part of life. Sculpture developed, usually with elongate spines or imbricated frills. Umbones prosogyrate,

migrating away from the margin due to tangential growth. Ligament external, split, early portions not 1

functional due to direction of shell growth. Hinge plate wide, with typical heterodont dentition in the juvenile,

m

becoming overgrown by tubercles to accomodate tangential growth. Dimyarian, with subequal adductor 1

muscles. Foot small. Mantle lobes fused, with pedal gape and two posterior apertures. Gills large, •

synaptorhabdic plicate, or heterorhabdic. Labial palps small to large. Alimentary canal with type 5 stomach; m

style-sac joined to the mid-gut; intestine passing through ventrical of heart.

I

!

!
I

I Genus Chama Linnaeus, 1758

Chama Linnaeus, 1758. Type species (SD Children, 1823; ICZN Opinion 484, 1957): Chama lazarus

i Linnaeus, 1758. Recent, Indo-Pacific.

Diagnosis. Shell irregular, very inequivalve, with cupped left and flat right valve. Left valve cemented

i toSculpture substrate.of foliaceous Umbones recurved, commarginal prosogyrate, frills. Right unequal; valve commarginal left valve usually lamellae withordeepspines, subumbonal frequentlychamber. eroded.

Adult hinge plate strong with ponderous tubercles.

I Chama arcana Bernard, 1976

I Figure 5.32

Chama pellucida Broderip, auctt., non Broderip, 1835.

I Chama arcana Bernard, 1976: 14.

Material Examined. California, Santa Mafia Basin, Phase I, Sta.BSS-25 (390 m).--Holotype (see

below).

I Description. Shell orbicular, much distorted. Cemented by left valve. Left valve cupped; right

valve nearly flat. Sculpture of commarginal lamellae. Interior margin minutely crenulate. Hinge plate irregular,

I with obscure T tubercles. Length to 60 mm. ype Locality and Type Specimens. Newport Bay, California; Holotype, LACM 1723.

Distribution. Pacific Grove, California (37 ° N), to Bahia Magdalena, Baja California Sur (25 ° N),

I and in the Gulf of California, in the intertidal zone - 390 m.

Literature. Bernard (1976:14-15), Gill (1985: 28-29), Hadedie and D. P. Abbott (1980: 368),

i Skoglund (1991 a), Taylor and Kennedy (1969).

I

I

I

I

I A B

I Figure 5.32. Chamaarcana: A, exterior of right valve; B,interior of left valve.

I 149
N

Genus Pseudochama Odhner, 19t7 n

Pseudochama Odhner, 1917. Type species (SD Gardner, 1926): Chama cristella Lamarck, 1819. Recent,

Indo-Pacific. I

Diagnosis. Similar to Chama, but attached by the right valve.

Remarks. For a long time this genus was merged with Chama either completely, or as a subgenus. H

i

Beside the valve of attachment, consistent differences in the hinge or sculpture cannot be found. However, I

juveniles show differences in the dentition, but the constraints of spiral growth impose a similar pattern on

the two genera. There is no suggestion that settlement may be by either valve and is consistent in the two 1

genera. The genus is often colonial and may be found in large fused masses and clusters on rocky reefs.

Pseudochama exogyra (Conrad, 1837) n

Figure 5.33

Chama exogyra Conrad, 1837: 256. n

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-1 (98 m), BSS-16 (591 m).

Description. Shell ovate, usually distorted. Broadly cemented by deeply cupped right valve; left i

valve flattened, lid-like. Sculpture of uneroded specimens of small commarginal lamellae and irregular

spines. Interior white, sometimes blushed with pink. Inner shell margin smooth. Hinge plate irregular, with •

tubercles. Length to 40 mm. 1

Type Locality and Type Specimens. Santa Barbara, California; Syntypes BMNH 1961.5.20.155.

Distribution. Monterey Bay, California (36.7° N), to Cabo San Lucas, Baja California Sur (23° N), _l

in the intertidal zone - 591 m. ll

Literature. Bernard(1976: 26-27), Hertz and Skoglund (1991), Kellogg (1915: 669-671), Haderlie

and D. P. Abbott (1980: 368), Yonge (1967). •

!

!

!

i _ .

...,_..

•\ .._.._:

.. ...,

Figure 5.33. Pseudochama exogyra: A, exterior of left valve; B,interior of right valve. I

150 !
!

I Superfamily Galeommatoidea J. E. Gray, 1840

i = Leptonacea J. E. Gray, 1847; Erycinacea Deshayes, 1850; Chlamydoconchacea Dall, 1884

Diagnosis. Shell aragonitic, small to minute, partly to entirely covered by mantle lobes in some.

i Hinge plate with small cardinal tubercles; lateral teeth obscure to well developed. Ligament mainly external, frequently with small resilium. Usually byssate.

Remarks. The superfamily, known from the Cretaceous, may be polyphyletic and comprises small

I to minute species, containing many symbiotic and commensal forms, usually associated with large infaunal invertebrates.

I Family Galeommatidae J. E. Gray, 1840

= Ephippiodontidae Scarlato and Starobogatov, 1979

I Diagnosis. Shell aragonitic, ovate to rounded, thin, small, inequilateral, equivalve, internal in some.

Sculpture absent. Periostracum thin, dehiscent. Hinge plate edentulous or variable, with cardinal tubercles;

i lateral teeth obscure, marginal, usually bent. Ligament variable, usually external opisthodetic, with a small internal resilium in an obscure resilifer. Dimyarian; adductor muscles subequat. Foot well developed, with

byssal groove. Mantle lobes extensively fused, with large pedal aperture and small posterior exhalant opening.

I Mantle usually extending over exterior of shell. Ctenidia synaptorhabdic, homorhabdic; outer demibranch usually absent. Labial patps small. Alimentary canal with type 4 stomach; ducts to digestive diverticula in 2

dusters; style sac separate from mid-gut; intestine passing through ventricle of heart.

I Remarks. The majority of members are less than 10 ram, and are far smaller. Many are

many

commensal with large sedentary or burrowing invertebrates, thus achieving the protection of a deep infaunal

habitat in spite of the absence or small size of the siphons. The family has secondarily developed an anteriorI posterior mantle current. It is also likely that the ventilatory current of the host brings additional food to

these filter-feeding species. Identification depends greatly on the external appearance of the living animal

and details of the hinge plate. The foot has a planar sole and is usually adapted for active crawling, rather

I like a gastropod. In many species, the mantle is greatly protrusible and may cover the external shell; the anterior mantle may carry two tentacles. The family is known back to the Eocene.

I New Genus, New Species A

Figure 5.34

I Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-83 (444 m), BSS-85 (113

m); Phase II, Sta. R-2 (161 m), R-3 (409 m), R-5 (154 m).

I Description. Shell extremely thin, fragile, transparent; subequilateral, posterior slightly longer, anterior end slightly flared. Sculpture predominately irregular radial striae, few commarginal growth striae.

Beaks low, wide.

I Mantle papillated, reflected, covering entire shell; fused posteriorly forming an exhalent siphon

and anteriorly forming an inhalent siphon. Long mantle papillae extend welt past shell margins. Foot

vermiform, without heel; long byssal groove extending to tip of smooth foot tip.

I Distribution. Known from the Santa Barbara Channel, California and the Barkely Sound,

British

Columbia (attached to Brissaster).

!

i 151
!

!

!

!

!

!

Figure 534. Galeommatidae newgenus, new speciesA: A,interior of left valve;B, exteriorof living animalfrom I

the left side.

i

Remarks. This new genus and species were discovered simulaneously by the author and Diarmaid

6 Foighil in British Columbia, Canada, and the author in Santa Barbara. British Columbia specimens were I

collected on echinoid specimens, whereas California specimens have yet to be associated with a host. The |

genus and species will be described in a forthcoming publication authored by both investigators.

ill

Family Lasaeidae J. E. Gray, 1842 I

= Kelliidae Forbes and Hardey, 1849; Erycinidae De shayes, 1850; Montacutidae W. Clark, 1855; ira

subfamilies Bomiinae, Mysellinae, Orobitellinae, Thecodontinae F. R. Bernard, 1983 II

Diagnosis. Shell aragonitic, thin to translucent, small to minute, inequivalve, rounded to elongate, III

inflated. Sculpture absent, rarely with radial riblets or commarginal lirae, occasionally with both. Umbones I

prominent, prosogyrate, submedial to posterior. Prodissoconch demarcated, minute. Periostracum thin. Hinge

plate strong, variable, stained red or purple. Right valve with strong lateral teeth, fitting into grooves in,

right valve, and with single, conical cardinal tooth. Ligament opisthodetic, parivincular, attached to small II

nymph. Resilium feeble, in small, obscure resilifer. Interior frequently stained brown or purple. Dimyarian;

muscle scars subequal. Byssate. Mantle lobes not fused, except for small posterior exhalant aperture. Inner II

mantle fold hypertrophied, covering much of shell exterior and projecting to form anterior hood. Mantle I

current anterior to posterior. Ctenidia synaptorhabdic, usually homorhabdic; outer demibranch reduced or

absent. Labial palps small. Foot long, compressed, with planar sole. Byssate. Alimentary canal with type 4 II

stomach; ducts of digestive diverticula concentrated on right wall of stomach; style sac not joined to mid- _

gut; intestine passing through ventricle of heart.

Remarks, Mostly minute parasitic or commensal forms. Most actively move using the planar sole •

of the foot. Following Boss (1982) I can find no consistent characters with which to separate the Erycinidae,

Kelliidae and Monticutidae from this family. Until such characters can be delineated I have chosen to

combine all members of these families into the Lasaeidae. The family is recorded as early as the Cretaceous. II

l

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152 I
!

I Genus Rochefortia Velain, 1877

Rochefortia Velain, 1877 (31 Dec.). Type species (M): R. australis Velain, 1877. Recent, Indian Ocean.

i Diagnosis. Shell small, subtrigonal to elliptical, subequilateral to strongly inequilateral. Umbones

opisthogyrate. Left valve edentate; fight valve with 2 subequal diverging cardinals Right valve overlapped

i by left valve. Remarks. Several Rochefortia species are common members of the benthic infauna from Alaska to

the equator. They have been observed as free-living individuals or associated commensally with a wide

I variety of invertebrate hosts. The size and structure of the labial palps is a key anatomical character for discriminating between

species. Several species have elongate palps which have few sorting grooves, while others have trigonal

palps with many sorting grooves. The gills of all Rochefortia species consist of only one demibranch, with the outer demibranch absent, howeverMysella (Montacutona) possesses a vestigial outer demibranch (Morton

1971). The number of gill filaments also can be useful in separating species.

I has often been combined with 1877, however the two subequal diverging Rochefortia Mysella Angas,

cardinal teeth in the former are distinctive.

i The genus is recorded back to the Pliocene.

Roehefortia compressa Dall, 1913

I Figure 5.35

Rochefortia compressa Dall, 1913: 596.

Material Examined. California, Santa Mafia Basin, Phase I, Sta.BSS-26 (590 m); Phase II, Sta.

PJ-15 (155 m).--Holotype (see below).

i Description. Shell of medium size, length to 10 mm; beaks prominent, inequilateral, longer anteriorly, subquadrate; compressed; very thin, fragile; white to transparent; periostracum adherent, very thin, transparent,

dull to silky; surface rough but without sculpture, with minute commarginal growth striae.

i left valve with 2 cardinal teeth below beaks; valve edentulous,

Hinge plate very weak; slight fight

but with very weak lateral projection on either side of beaks, projections fit into left valve between cardinal

teeth and dorsal margin; resilifer very small; adductor scars subovate, weakly impressed; pallial line weakly

I impressed.

Type Locality and Type Specimens. Bahia Concepcion, Baja California Sur, Mexico. Holotype:

USNM 21445.

I Distribution. Santa Barbara, California (34.4 ° N) [SBMNH], throughout the Golfo de California

[LACM] to Bahia Culebra, Costa Rica (10.6 ° N) [Skoglund Collection] andpossibly south to Zorfitos, Peru

(3.7 ° S) Literat (Olsson, u 1961), in 5 - 590 m. re. Keen (1971: 142), Olsson (1961: 234).

I

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i 153
I

I

1

I

I

I

I

Figure 5.35. Rochefortia compressa: A, detail of hinge in right valve; B, exterior of left valve.

Rochefortia grippi Daft, 1912 I

Figure 5.36 I

Rochefortia grippi Dall, 1912: 128.

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-21 (49 m); Phase II, Sta. R- i

8 (90 m).--Holotype (see below).

Description. Shell small; equilateral, ovate/elongate, anterior and posterior margins evenly rounded; Iii

moderately inflated; thin; white; periostracum thin, adherent, silky to shiny, medium-brown; surface without I!

sculpture, but with commarginal growth striae; beaks prominem. Length to 5 mm.

Left valve with 2 small cardinal teeth of equal size, one on each side of resitifer, both parallel to _ i

dorsal margin; resilifer very small, with an obscure lithodesma; adductor scars weakly impressed; pallial

line weakly impressed.

Anatomy in distinct conla-ast toMysella tumida. Gill filaments numerous, about 31, narrowly spaced, i

Adductor muscles ovate, sub-equal. Labial palps large, elongate; sorting grooves on palps well demarcated,

almost forming separate fingers.

Type Locality and Type Specimens. California, off San Diego, 16-20 fm. Holotype: USNM 214363 1

(holotype has brooding larvae). I

Distribution. Esperanza Inlet, Vancouver Island, British Columbia (49.8 ° N) [LACM], to San

Diego (32.7 ° N) [USNM], California, in 10 - 120 m. i

I

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I

154 I
i

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I

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I

!

i Figure 5.36. Rochefortia grippi: A, detail of hinge in right valve;B, exterior of left valve.

i Rochefortia tumida (Carpenter, 1864) Figure 5.37

t Tellimya tumida Carpenter, 1864: 602, 611,643. Mysella aleutica Dall, 1899:881,892, 896, pl. 87, fig. 8.

Rochefortia Mateferruginosa Dall, 1916: 29, nont nud.; 1916a: 411 rial Examined. California, Santa Maria Basin, Phase I, Sta.BSS-64 (59 m); Phase II, Sta. R1 (98 m), R-8 (308 m).--Holotype (see below).

I Description. small, length to mm; ovate to subquadrate; inequilateral,

Shell 4 anterior longer, evenly

rounded; posterior truncate; inflated to moderately compressed; shell very thick for small size; white to dark

brown; periostracum thick, adherent, light to dark brown, generally eroded from beaks; surface smooth

i for striae; beaks almost to posterior margin. except commarginal growth prominent, extending

Right valve with 2 sturdy cardinal teeth, one on each side of resilifer; posterior tooth projecting

i ventrally from beaks, anterior tooth projecting from beaks parallel to dorsal margin; left valve without cardinal teeth but with slight lateral projection on either side of beaks, projections fit into left valve between

cardinal teeth and dorsal margin; resilifer of moderate size; adductor scars subequal, ovate/elongate,

moderately impressed, posterior scar slightly longer and more elongate than anterior; pallial line moderately

i impressed.

Gill filaments are few, about 26, widely spaced; an obvious demarcation present between ascending

I and grooves. descending Adductorlamellae. musclesFoot unequal, relativelywithlarge, elongate, comprcurved essed. Labial anteriorpalps adductor small,andtrigonal, small,with ovatefewposterior sorting

adductor muscle.

i USNM 5242. Type Locality and Type Specimens. Washington, Puget Sound, Strait of Juan de Fuca. Holotype

Distribution. Beaufort Sea, Alaska (71 °) to San Diego, California (33°N); in the Gulf of California

I at Puerto Pefiasco, Sonora, Mexico (31°N); intertidal - 308 m. Literature: F. R. Bernard (1979: 39-40), U. S. Grant and Gale (1931: 301), Hertlein and Grant

(1972: 239-240), Maurer (1967a, c, 1969), E. J. Moore (1992: 9), 0 Foighil (1985b), 6 Foighil and Eemisse

I (1987), Scott (1987), Strathmann (1987: 333-334).

i 155
I

!

!

!

!

!

!

Figure 5.37. Rochefortia tumida: A, interior of right valve; B, exterior of left valve.

,B

Rochefortia sp. A

Figure 5.38 ii

Material Examined. California, Santa Maria Basin, Phase II, Sta.R-1 (91 m). •

Description. Shell subovate, very thin, fragile, compressed. Inequilateral, anterior much longer. n

Anterior and posterior ends broadly rounded. Sculpture of very free commarginal striae. Periostracum very

thin, transparent. Umbones small, not produced. Right valve with 2 very small, subequal, diverging cardinal i

teeth. Length to 5 mm. !1

Distribution. Off Coos Bay, Oregon (43.3 ° N) [SBMNH], to San Diego (32.7 ° N) [SBMNH],

California, from intertidal to 91 m. I

Rochefortia sp. B

Figure 5.39 i

Material Examined. California, Santa Mafia Basin, Phase I, Sta.BSS-73 (98 m); Phase II, Sta. R- i

4 (92 m) l

Description. Shell subquadrate, thin, fragile, compressed. Irtequilateral, anterior longer. Anterior

and posterior ends truncate. Sculpture of heavy irregular commarginal ribs. Periostracum thin, often covered i

with ferruginous mud. Umbones small, not produced. Right valve with 2 small, subequal, diverging cardinal !1

teeth. Length to 5 mm.

Distribution. Santa Mafia (35.1 ° N) [SBMNH], to San Diego (32.7 ° N) [SBMNH], California, i

from 45 - 165 m.

!

!

156 i
I

I

I

I

i

I

i Figure 5,38. Rochefortia sp A: A, detail of hinge in fight valve; B, interior of right valve.

i

i

1

i

!

i Figure 5.39. Rochefortia sp. B: A, interior of fight valve; B, exterior of left valve.

I Rochefortia sp. C

Figure 5.40

i Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-21 (49 m); Phase II, Sta. R1 (91 m), PJ-7 (123 m), PJ-15 055 m).

i Description. Shell ellipsoid, inequilateral, moderately inflated, thin, without extemat sculpture.

Beaks prominent, almost to posterior margin, opisthogyrate. Cardinal teeth small, anterior tooth larger.

Length to 4 mm.

I Distribution. Santa Maria Basin to Los Angeles Harbor, California, in 49 - 155 m.

!

I 157
!

!

!

!

!

!

Figure 5,40. Rochefortia sp.C: A, interior of right valve;B, exterior of left valve, l

Superfamily Cardioidea Lamarck, 1809 I

Diagnosis. Shell aragonitic, subtrigonate to subquadrate, inequilateral, usually solid, inflated, and

equivalve. Periostracum thin, frequently abraded. Sculpture predominently radial. Hinge plate variable, /

usually with 2 conical cardinal teeth; laterals short and distant; dentition evanescent or absent in adult of a J

few taxa. Ligament external, on strong nymph, opisthodetic, parivincular, sunken into groove. Dimyafian.

Family Cardiidae Lamarck, 1809 I

Diagnosis. Shell aragonitic, with outer fibrous prismatic, cross-tamellar middle, and complex cross- ill

lamellar inner layers. Ovoid to rounded, equivalve and inflated, frequently higher than wide. ScuIpture of II

radial ribs, sometimes spinose or frilled; sculpture absent in few. Periostracum thin and adherent. Umbones

prominent. Hinge plate wide, with 2 conical, hooked cardinal teeth in each valve. Cardinal teeth cruciform IIi

when valves interlocked. Left valve with 1 anterior and 1posterior lateral tooth; fight valve with 1 anterior |

and 1 or 2 posterior lateral teeth. Ligament short, external, opisthodetic, in a groove. Dimyarian, with

subequal adductor muscles. Mantle lobes with wide pedal opening, occasionally with small area of fusion

setting off exhalant aperture; small siphons sometimes present. Foot long and geniculate. Gills synaptorhabdic, |

plicate and heterorhabdic. Labial palps small and narrow. Alimentary canal with type 5 stomach; ducts to

digestive diverticula numerous, in right and left clusters; style-sac joined to mid-gut; intestine passing I

through ventricle of heart. I

Genus Nemocardium Meek, 1876 R

II

Nemocardiurn Meek, 1876. Type species (SD Sacco, 1899): Cardium semiasperum Deshayes, 1858. Eocene,

France.

Ill

Diagnosis. Sculpture of radial ribs and striae, usually stronger on posterior slope; central slope _!

sometimes nearly smooth; ribs on posterior slope often spinose; inner ventral margin crenulate.

l

t

158 |
!

!

!

! A B

!

i Figure 5.41. Nemocardium centifilosum: A, detail of hinge infight valve;B, exterior of left valve.

Nemocardium centtfilosum (Carpenter, 1864)

i 5.41 Figure

Cardium (?modestum vat.) centifiIosum Carpenter, 1864a: 611; 1866: 209.

i Cardium richardsoni Whiteaves, 1878: 468.

Material Examined. California, Santa Mafia Basin, Phase I, Sta.BSS-73 (98 m), BSS-102 (99 m);

I Phase II, Sta. R-4 (92 m), R-8 (90 m).

Description. Shell ovate, thin and inflated. Sculpture of posterior slope cancellate, with about 20

radial ribs, separated from central slope by a raised radial rib. Central and anterior slopes with 40 or more

I free radial ribtets. Umbones prominent, margin finely Length to mm.

subcentral. Inner crenulate. 25

Type Locality and Type Specimens. Catalina Island, California; Holotype USNM 15262.

I

the intertidal Distrizone bution.to 150Kodiak m. Island, Alaska (58 ° N), to Punta Rompiente, Baja California Sur (27.7 ° N), in

Literature. Fischer-Piette (1977: 6), Schneider (1992).

!

Superfamily Veneroidea Rafinesque, 1815

I Shell inequilateral andequivalve. Umbones anterior, Ligament

Diagnosis. aragonitic, prosogyrate.

opisthodetic, parivincular, on nymph. Hinge plate broad; teeth strong, with up to 3 cardinal teeth in each

valve; lateral teeth present or absent. l

I Family Veneridae Rafinesque, 1815

Diagnosis. Shell aragonitic, usually with a composite prismatic outer, homogenous or cross-lamellar

middle, and complex cross-lamellar inner layers. Usually thick, ovate to suborbicular or subtrigonate,

i inequilateral and equivalve. Umbones prosogyrate, subcentral to anterior. Periostracum inconspicuous, frequently abraded. Sculpture absent or of strong commarginal or radial ribs, sometimes spinose or lamellate.

Lunule and escutcheon usually present. Ligament external, opisthodetic, parivincular on strong nymph.

I Hinge plate wide, with three cardinal teeth in each valve, generally thickened and bifid. Lateral teeth variable,

I 159
!

frequently absent. Foot large, compressed, with byssal groove. Pallial line entire, usually with deep pallial i

sinus. Mantle edge with 4 folds; lobes fused leaving large pedal opening; posterior openings usually with

short, united siphons. Gill large, synaptorhabdic, plicate andheterorhabdic. Labial palps small and triangular. I

Alimentary canal with type 5 stomach; numerous ducts to the digestive diverticula; style-sac joined to mid- 1

gut; intestine passing through ventricle of heart.

Genus Compsomyax Stewart, 1930 I

Compsomyax Stewart, 1930. Type species (OD): Clementia subdiaphana Carpenter, 1864. Recent, Puget

Sound, Washington. !

Diagnosis. Shell thin and porcellaneous. Sculpture of weak commarginal striae. Posterior right

cardinal tooth strong and bifid; lateral teeth absent. I

Compsom yax subdiaphana (Carpenter, 1864)

Figure 5.42 i

Clementia subdiaphana Carpenter, 1864a: 640; 1865e: 56. I

Saxidomus gibbosus Gabb, 1869: 58. _

Callista subdiaphana pedroana Arnold, 1903: 144.

obliqua Jukes-Browne, 1913: 59. I

Clementia

Material Examined. California, Santa Mafia Basin, Phase I, Sta.BSS-21 (49 m); Phase II, Sta. R1 (91 m); R-8 (90 m).iHolotype (see below). 1

lm

Description. Shell subquadrangular, very inflated and thin. Sculpture of weak commarginal striae.

Periostracum thin, with adherent sand grains in living material. Umbones anterior, prosogyrate. Hinge plate

feeble; posterior cardinal tooth of right valve valve bifid. Pallial sinus large. Length to 85 mm. !

Type Locality and Type Specimens. Puget Sound, Washington; Holotype, USNM 454I.

Distribution. Cook Inlet, Gulf of Alaska (61 ° N), to Bahia San Quintin, Baja California [Norte] Ill

(30 ° N), in 2 - 500 m, in soft mud, frequently in areas with high organic content. Recorded as early as the II

late Miocene in western North America.

Literature. Fischer-Piette and Vukadinovic (1972:165), Hertlein and Grant (1972: 269-270), Jukes- I

Browne (1914), L. S. Smith and Davis (1965), Williamson (1893), Woodring (1926). U

I

!

•_.i .. " :.::_.;"

:'_D ...

Figure 5.42. Compsomyax subdiaphana: A, exterior of left valve; B, interior of right valve. I

160 1
I

I Superfamily Tellinoidea Blainville, 1814

Diagnosis. Shell rounded to subtrigonal or elongate, inequilateral, compressed, equivalve in most.

I Periostracum thin and adherent. Sculpture variable, usually commarginal. Ligament opisthodetic

and

parivincular, either external set on nymph, or internal in resilifer. Hinge plate strong, usually with 2 cardinal

teeth in each valve. Lateral dentition may be present, or vestigial. Pallial sinus impressed; pallial sinus

I strongly developed. Dimyarian. Unique present siphons.

CTUC_'OTITI muscles at base of

Remarks. The Tellinoidea arose in the Triassic and comprise one of the largest bivalve superfamilies,

i with numerous groups adapted to a wide variety of shallow water, infaunal habitats. Cosmopolitan in distribution, but especially abundant in tropical regions. Many forms are particularly important ecologically

because of their abundance, and a number of species are important food sources. Among the most attractive

i of bivalves, their elegant shells are frequently brightly colored. Four living families with approximately 550 species are recognized. All the families are represented in the northeastern Pacific.

i Family Tellinidae Blainville,

18 14

i Diagnosis. Shell aragonitic, with prismatic outer, cross-lamellar middle, and complex cross-lamellar inner layers. Usually with rounded anterior end and an elongate posterior end, equivalve to inequivalve,

occasionally with posterior flexure. Sculpture variable, commarginal and subdued. Periostracum thin,

i varnished. Ligament external, on weak, elongate nymph. Hinge plate narrow; 2 cardinal teeth in each valve; lateral teeth, when present, stronger in the right valve. Dimyarlan; adductor muscles subequal. Foot

compressed, broad and linguiform. Pallial line strong; pallial sinus deep, frequently differing in the two

valves. Gills synaptorhabdic. Mantle lobes fused, with large pedal gape and long, separate siphons. Labial

i palps large triangular. Alimentary type stomach; numerous digestive

and canal with 5 ducts to diverticula;

style-sac joined with mid-gut; intestine passing through ventricle of heart.

I Genus Tellina Linnaeus, 1758

Tellina Linnaeus, 1758. Type species (SD Children, 1823): Tellina radiata Linnaeus, 1758. Recent,

I Caribbean.

Diagnosis. Shell elongate, compressed. Hinge plate with 2 cardinal teeth in each valve and with

I lateral teeth in one or both valves, sometimes ephemeral. Often brightly colored and elegantly sculptured.

TeUina modesta (Carpenter, 1864)

I Figure 5.43

I Angulus Angulus modestus modestus Carpenter, obtusus Carpenter, 1864b: 681; 1864b: 1865f: 639;56. 1865f: 56, non Tellina obtusa J. Sowerby, 1817.

Tellina (Oudardia ) buttoni Dall, 1900: 326, nom. nov. pro T. obtusa Carpenter, non J. Sowerby.

I Material Examined. California, Santa Maria Basin, Phase II, Sta.PJ-7 (123 m).--Lectotype (see

below).

I Description. Shell small, elongate, moderately inflated, generally with internal radial riblet just behind anterior adductor muscle scar. Periostracum highly polished; sculpture absent to weakly commarginal.

Color white. Length to 20 ram.

!

. 161
!

I

.6. B i

II

Figure 5.43. Tellina modesta: A, interior of right valve;B, interior of left valve, g

Type Locality and Type Specimens. Puget Sound, Washington; Lectotype, USNM 4245. N

Distribution. Cook Inlet, Alaska (60 ° N), to Bahia San Bartolome, Baja California Sur (28 ° N) in

the intertidal zone to 100 m, in fine sandy sediments in bays or open coast.

I

Literature. Coan (197 I), Maner (1967a-c, 1969).

TeHina earpenteri Dall, 1900 N

Figure 5.44

II

Angulus variegatus Carpenter, 1864b: 629; 1864e: 423, non Tellina variegata Gmelin, 1791. J

Tellina (AnguIus) carpenteri Dall, 1900: 320, nora. nov. pro T. variegatus (Carpenter), non Gmelin.

Tellina (Moerella) arenica Hertlein and Strong, 1949: 68. I

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-85 (113 m), BSS-86 (197

m).--Holotype (see below). I

lW

Description. Shell elongate, inflated, pink or rose-colored, lacking an internal radial riblet. Sculpture

absent or of fine commarginal striae. Habitat influences the form, those from offshore situations are pale Ill

and compressed, while those from shallow bays are more inflated and brightly colored. Length to 20 mm. EW

Type Locality and Type Specimens. Neah Bay, Washington; Lectotype, USNM 15467b.

Distribution. Sitka, Alaska (57 ° N), to San Pedro, California (34 ° N), and in deeper water south to ]l

Corinto, Nicaragua (12 ° N), in the intertidal zone to 450 m. n

Literature. Coan (1971: 15-16), Hertlein and Strong (1949: 68-69).

!

Genus Maco_a Leach, 1819

Macoma Leach, 1819. Type species (M): Macoma tenera Leach, 1819, = Tellina calcarea Gmelin, 1791.

Recent, North Atlantic. a

Diagnosis. Shell ovate to subtrigonal, inaequilateral. Sculpture usually absent, or weakly

commarginal. Periostracum thin, frequently abraded. Two cardinal teeth in each valve; lateral teeth absent. II

Pallial sinuses discrepant, longer in left valve.

!

162 I
I

i

i

I

I

i Figure 5.44. Telfina carpenteri: A,interior of right valve; B,interior of left valve.

I Macoma yoldiformis Carpenter, 1864

Figure 5.45

I Macoma yoldiformis Carpenter, 1864b: 639; Carpenter, 1865f: 55.

i Material Examined. California, Santa Mafia Basin, Phase I, Sta.BSS-21 (49 m); Phase 11,Sta. R- • 8 (90 m), PJ-17 (126 m).--Lectotype (see below).

Description. Shell elongate, thin, and very inflated shell; postero-dorsal margin produced into flange.

t Periostracum thin, adherent. Pallial sinus is mostly detached from pallial line, approximately equal in size

in each valve. Length to 25 mm.

Type Locality and Type Specimens. Neah Bay, Washington; Lectotype, USNM 4507.

I Distribution. Sitka, Alaska (57 ° N) [RBCM], to Bahia San Bartolome, Baja California Sur (28° N),

in the intertidal zone to 100 m, in bays and protected foreshores in sand or mud. Recorded as early as the

Pliocene in the eastern Pacific. It is possibly related toM. wilcoxi Hall andAmbrose, 1916, from the Miocene

I of California.

Literature. Coan (1971: 33-34), Dunnill and Ellis (1969: 30-33).

I

I

, @

I

.I Figure 5.45. Macoma yoldifor_is: A, interior of right valve; B, interiorof left valve.

. 163
I

i

I

"_\ I

B c li

Figure 5.46. Macomavalves carlottensis . : A, interior of right valve; B, interior of left valve; C, posterior view of both 1

II

Macoma carlottensis Whiteaves, 1880 [n

Figure 5.46

dim

Macoma carlottensis Whiteaves, 1880: 196B. I

Macoma leptonoidea Dall, 1895: 33.

Macoma inflatula Dall, 1897: 11. U

Macoma quadrana Dall, 19t6: 37, nom. nud.; Dall, 1916a: 414.

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-55 (590 m), BSS-89 (471 I

m); Phase II, Sta. PJ-9 (169 m). w

Description. Shell trigonal to elongate, thin, more inflated anteriorly. Periostracum adherent, II

polished, usually straw-colored. Pallial sinus larger in left valve. Length to 30 mm. U

Type Locality and Type Specimens. Virago Sound, Graham Island, Queen Charlotte Islands,

British Columbia; Lectotype, NMC 316. I

Di II stribution. Lituya Bay, Alaska (59 ° N), to Islas Los Coronados, Baja California [Norte] (32 ° N)

in the subtidal zone to 1,550 m, in mud or fine sand. Also known in the Pleistocene of California.

Literature. Bright (1988), Coan (1971: 35-37), Dunnill and Ellis (1969: 13-15). I

U

Family Bernardinidae Keen, 1969 I

Diagnosis. Shell small to minute, solid, equivalve and subequilateral. Lunule and escutcheon absent.

Hingein obscureplateresilifer.Pr°mi withnen2 ot'r 3 large cardinal teeth and 2 or more lateral teeth. Ligament mostly internal I

Genus Halodakra Olsson, 196I I

Halodakra Olsson, 1961. Type species (OD): Circe subtrigona Carpenter, 1857. Recent, California.

Diagnosis. Shell ovate to suborbicular, inequilateral; posterior end produced. Sculpture absent, or 1

of commarginal striae. Posterior area with chevron-shaped color markings. Umbones prosogyrate. Lunule

obscure or demarcated. Hinge plate strong with 1 to 3 cardinal teeth; lateral teeth sometimes present. Ligament

internal in shallow resilifer. Juvenile byssate. I

|
!

!

!

!

!

!

Figure 5.47, Hatodakra salmonea: A, hinge of left valve; B, hinge of right valve. (after Coan, 1984).

I

Halodak_ salmonea (Carpenter, 1864)

I Figure 5.47

i Psephis Crassatellaslmonea marginata Carpenter, Kep, 1864:87 641. 179, ex Carpenter MS.

Psephidia brunnea Dall, 1916: 34, nom. nud.; 1916a: 413.

t Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-22 (99 m).

Description. Shell ovate to subtriangular; posterior end produced. Sculpture of commarginal striae.

I Color usually reddish, rarely white, generally with blush of brown on umbo. Length to 5 mm.

Type Locality and Type Specimens. San Diego, California; Lectotype, USNM 15578.

Distribution. Banks Island, British Columbia (53.5° N) to Rocas Alijos, Baja California (25° N), in

I 20 - 99 m, among rubble in rocky areas.

Literature. Coan (1984:231-233), Howard (1953).

I Order Myoida Goldfuss, 1820

I SculptureDiagnosis. absent Shell aragonitic, subequilateral to strongly inequilateral, equivalve or inequivalve. to highly developed in some groups. Umbones not prominent. Lunule and escutcheon

obscure or absent. Ligament external, or internal in resilifer or prominent chondrophore. Occasionally with

l lithodesma. Hinge plate edentate, or with pseudocardinal tubercle in each valve.

Superfamily Hiatelloidea J. E. Gray, 1824

l Diagnosis. Shell aragonitic, t.hick, quadrate to trapezoidal, frequently irregular or distorted, inflated,

equivalve. Sculpture absent, or of irregular commarginal striae. Periostracum thick, usually layered and

i bridging Hinge platehingestrong, region. oftenLigament edentate,external but withparivincular obscure denticles and mainly or ephemeral opisthodetic, tubercles. attached Sometogenera strong byssate. nymph

I

i 165
!

Family Hiatellidae J. E. Gray, 1824 i

Diagnosis. Shell aragonitic, with prismatic outer, homogenous middle, and complex cross-lamellar i

inner layers. Shell usually thick; outline ovate to elongate, with extensive gape. Sculpture absent, or weakly II

commarginal. Periostracum strongly developed, dehiscent, usually covering mantle edge and prolonged

into siphonal sheath. Ligament external, opisthodetic and parivincular. Hinge plate irregular, with 1 or 2 i

submarginal denticles possibly ephemeral. Dimyarian, with subequal adductor muscle scars. Pallial line il

deeply impressed, frequently discontinous; pallial sinus variable. Ctenidia synaptorhabdic and homorhabdic,

usually extending into exhalant siphon. Foot usually small, digitiform, with byssal groove, many groups tl

byssate when adult. Mantle lobes extensively fused, usually thick, with small pedal aperture and fourth II

pallial aperture in some. Siphons large, fused for most of length. Alimentary canal with type 4 stomach;

ducts to digestive diverticula in 3 clusters; style-sac conjoined with mid-gut; intestine passing through I

ventricle of heart. II

Literature. Keen (1969x), Lamy (1924-1925), Tryon (1869), Yonge (1971).

Genus ttiateIla Bosc, 1801 .!

Hiatella Bosc, 1801, ex Daudin MS. Type species (SD Winckworth, 1932):Hiatella monoperta Bosc, 1801, ll

ex Daudin MS, = Mya arctica Linnaeus, 1767. Recent, Norway. IN

Saxicava Fleuriau de Bellevue, 1802. Type species (M): S. striata Fteuriau de Bellevue, 1802, =Mya arctica

Linnaeus, 1767. I

Diagnosis. Shell ovate to trapezoidal, usually distorted, chiefly nestling, but able to enlarge its

home somewhat by mechanical action. Inequilateral and equivalve, usually gaping. Sculpture absent, or ]Ira

feebly commarginal, rarely with 1 or 2 posterior radial rows of spines in juvenile. Hinge plate weak and II

irregular, usually with 1 or more cardinal denticles sometimes lost in adult. Byssate.

Ill

Hiatella arctica (Linnaeus, 1767) D

Figure 5.48 I

i

Mya arctica Linnaeus, 1767:1113.

Mytilus pholadis Linnaeus, 1771: 548. al

Saxicava orientalis Yokoyama, 1920: 106. II

[there are many more synonyms throughout the world].

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-20 (396 m); Phase II, Sta. R- R

4 (92 m).

Description. Shell usually distorted; sculpture of irregular commarginal growth lines. Umbones n

prominent, prosogyrate, near anterior end. Some individuals with 1 or 2 external radial ridges on posterior !11

slope that may be spinose, particularly on small specimens. Periostracum thin, not investing white or red

tipped siphons. Small, distinct lunule present. Ligament attached to weak nymph. Hinge plate feeble; right n

valve with one ephemeral denticle, 2 in left valve, but may be erroded and lost. Length to 78 ram. I

Type Locality and Type Specimens. Norway, types possibly at the Linnean Society of London.

t

!

166 I
!

!

!

•.__..,:.

| A B

I Figure 5.48. HiateUa arctica: A, exteriorof left valve;B, interiorof left valve.

I Distribution. Point Barrow, Alaska (71 ° N) along the west American coast to Chile, in the intertidal

zone to 800 m.

• ! Remarks. This highly variable species is the dominant byssally attached bivalve of Arctic and

t

boreal regions. There is tantilizing evidence that there is more than one species in this genus: eggs of two

colors (red and pinkish cream), two post-larval forms (oval and triangular), and siphon tips of two colors

i (red and white). Unfortunately, these traits have not been correlated with with shell morphologies or type material. Full taxonomic understanding of this genus is a problem that cries out for attention with modern

methodologies grounded in sound nomenclature and with type specimens.

i Strauch (1968, I970, 1971) found that size of this species is correlated with water temperature and

can be used to estimate paleotemperatures, but other workers are not as certain of this (Rowland and Hopkins,

1971).

I Literature. Ali (1970), Barrois (1879), F. R. Bernard (1979: 56-57), Beu (1971), N. MacGinitie

(1959: 190-191), Narchi (1973), Ockelmann (1959: 135-142), Yonge (1971). For additional references, see

i Clapp and R. Kenk (1963).

Genus SaxicavelIa Fischer, 1878

I SaxicavelIa P.-H. Fischer I, 1878. Type species (M): "Mytilusplicatus Gmelin, ex Chemnitz MS," Montagu,

1808, non Gmelin, 1791, = Saxicavellajeffreysi Winckworth, 1930; ICZN Code Art. 70c. Recent,

northeastern Atlantic.

i Diagnosis. Shell small, elongate, rhomboidal, thin, slightly gaping. Umbones not prominent.

Periostracum dehiscent. Ligament short, prominent, mostly external, on very short nymph just posterior to

I beaks. Siphons absent. Pallial line continuous; pallial sinus absent.

Remarks. The name is a diminutive based on the Latin saxum, a stone, and cavator, an excavator;

the gender is feminine. This genus occur back to the Late Paleocene or Eocene. ,!I

!

!

i 167
!

Saxicavella nybakkeni P. H. Scott, 1994 I

Figure 5.49

II

Saxicavella nybakkeni. P. H. Scott, 1994:65 l

Material Examined. California; 10 lots of southern and central California. i

D li escription. Short, rhomboidal. Posterior end longer, broad; posterior gape wide. Surface smooth,

with commarginal growth striae. Ligament small, deeply sunken, not protruding. Periostracum tan, adherent.

Length to 10 ram. I

RD Remarks. The juveniles of this species are brooded in an external pouch between the inner and

outer mantle folds. It is somewhat similar to the Caribbean S. sagrinata Dall and Stimpson, 1901, which has

a granular shell suface, narrower beaks, a small cardinal tubercle, and a shallow nymph, i

u

Distribution. San Francisco (37.7 ° N) [CAS] to San Diego (32.7 ° N) [SBMNH], California, in 31-

61 m.

Im

Literature. P. H. Scott (1994). R

Saxicavella pacifica Dall, 1916

Figure 5.50 i

Saxicavellapacifica Dall, 1916a: 42, nom. nud.; 1916b: 416. i

almim.

Material Examined. California, Santa Maria Basin, Phase I, Sta.BSS-76 (387 m).

Description. Shell rhomboidal-elongate, narrow anteriorly, longer, broad posteriorly. Sculpture of R

feeble commarginal growth lines. Periostracum thin, tan, adherent. Posterior slope set off by obscure radial f

ridge. Posterior gape small. Hinge plate with minute cardinal denticle in right valve in juveniles, overgrown

in larger specimens. Ligament distinct, external, protruding. Length to 8 rrLm. n

i

Remarks. This species is similar to the European S. jeffreysi Winckworth, 1930, differing in being

more rhomboidal, with a narrower anterior end and a proportionately broader posterior end. I

Type law.aiRy and Type Specimens. Off Pt. Loma, California, 120-131 fathoms; Holotype, USNM i

209912.

Distribution. Vancouver Island, British Columbia (49.8 ° N) [LACM], to San Diego, California

(32.7° N) [CSDOMP], in the subtidal zone to 100 m, nestling in cobbles or burrows, occasionally in kelp II

holdfasts.

I

A B I

m

Figure 5.49. Saxicavella nybakkeni: A, dorsal view of living animal; B, lateral view of living animal. (after •

Scott, 1984). I

168 'i
I

I

I

I

I A B _'_ '_"'_:

I Figure 5.50. Saxicavella pacifica: A, exterior of left valve; B, interior of right valve.

!

I Subclass Anomalodesmata Dall, 1889

i Diagnosis. Shell aragonitic, ovate to elongate, equivalve to strongly inequivalve. Periostracum

thin, adherent, occasionally with radial rows of pustules or adherent grains. Ligament opisthodetic, sometimes

vestigial, usually with internal section in resilifer or chondrophore, generally with supporting lithodesma.

Hinge plate thickened, edentate, or with pseudocardinal tubercle. Gills eulamellibranch, reduced or absent

in forms.

some

•1 Order Pholadomyoida Newell, 1965

i Diagnosis. Shell aragonitic, in 3 layers, ovate to subtrigonal, strongly inequilateral with anterior umbones. Periostracum thin, frequently pustulate, or with cemented sand grains. Ligament external,

opisthodetic, parivincular on nymph; internal ligament in resilifer. Hinge plate thickened, edentate, sometimes

with amorphous tubercles. !

Superfamily Pandoroidea Rafmesque, 1815

I Diagnosis. Shell slightly to markedly inaequivalve, inequilateral, compressed to medially inflated.

Interior nacreous. Periostracum adherent, frequently granulated. Sculpture absent or commarginal, rarely

i radial. Ligament external, feeble; valves bridged by periostracum; internal ligament strong, in resilifer, sometimes supported by elongate lithodesma along antero-posterior axis. Hinge plate edentate, or with

tubercles, usually buttressed. Some groups byssate in adult.

!

!

!

I 169
!

Family Pandoridae Rafmesque, 1815 I

Diagnosis. Shell aragonitic, with prismatic outer, lenticular nacre middle, and sheet nacre inner •

layers. Outline inaequilateral, compressed, markedly inequivatve; right valve fiat; left valve convex and

overlapping. Sculpture absent or of commarginal lirae. Periostracum thin, occasionally with radial lirae.

Ligament external, amphidetic. Hinge plate absent, but with tooth-like crural ridges or lamina, on either

side of resilifer. Interior nacreous. Pallial line simple, frequently broken. Dimyarian; adductor muscle areas U

subequal. Foot with byssal groove, but adult not byssate. Mantle lobes not extensively fused, with large

pedal aperture, 2 short siphons and fourth pallial aperture. Gills heterorhabdic; outer demibranch with reduced el

descending lamella. Labial paips long, narrow. Alimentary canal with type 4 stomach; ducts to digestive II

diverticula; style-sac conjoined to mid-gut; intestine passing through ventricle of heart.

a

Genus Pandora Hwass, 1795 i

Pandora Hwass, 1795. Type species (SD Children, 1823): Pandora rostrata Lamarck, 1818, = Solen I

inaequivalvis Linnaeus, 1758. Recent, Mediterranean. |

Diagnosis. Shell strongly inequilateral; fight valve fiat; left valve convex. Hinge plate vestigial, I

with crural ridges bordering resilifer. Lithodesma usually present. Sculpture of irregular commarginal growth I

lines only. Interior nacreous. Siphons very short.

Pandora bilirata Conrad, 1855 i

Figure 5.51

ill

Pandora bilirata Conrad, 1855: 267, 1857: 73. D

Pandora (Kennerlia) bicarinata Carpenter, 1864b: 638; 1864e: 603. i

Pandora delicatula G. B. Sowerby II, 1874: sp. 17. i

Pandora granulata Dall, 1915: 449.

Pandora (Kenerlyia)pseudobilirata Nomura and Hatal, 1940: 87. i

i

Material Examined. California, Santa Mafia Basin, Phase II, Sta.R-8 (308 m).

Description. Shell elongate-ovate. Anterior end sharply rounded; posterior end rounded, not I

attenuate, with 1 to 3 strong radial ribs on left valve. Length to 15 mm. II

Type Locality and Type Specimens. California, types not located, possibly lost. I

i

, A e |

Figure 5.51. Pandora bilirata: A, exterior of left valve; B, exteriorof right valve. I

170 I
!

I Distribution. Kukak Bay (58° N) [CAS] and Prince William Sound (60 ° N), Alaska, to the Gulf of

California, and in the northwest Pacific from the Kurile Islands to Honshu, Japan; in the subtidal zone to 308

i m, in mud. LiteAlso raturknown e. U. S.as Grant early asandtheGale Piocene (1931:of261), CalifoHertlein rnia. and Grant (1972: 335-336), Hertlein and

Strong (1946: 97), Keen (1971: 289).

:!

Family Lyonsiidae Fischer, 1887

I Diagnosis. Shell aragonitic, with prismatic outer, lenticular nacre middle, and sheet nacre inner

layers; some also with homogeoeous middle layer. Outline suborbiculate to elongate, inequilateral and

I subequivalve, feeble, variable. usually Periostracum thin and fragile. thin toUmbones extremelyprosogyrate, thick, dehiscent, anterior.often Valveswithoverlapping adherent particles. ventrally. Ligament Sculpture

opisthodetic; resilium in marginal resilifer, supported by short to elongate lithodesma. Hinge plate irregular,

I edentate. Mantle lobes Dimyarian; fused; pedal adducaperture tor musclarge le scars to small; smallfourth and subeq pallialual.aperture Pallial present; line imprsiphons essed; palti shortalandsinusseparate. small.

Foot large and compressed in Lyonsia, small and veneriform in Entodesma and Mytilimera, with byssal

I palps groove;longadultandbyssate. narrow.Gills Alimentary heterorhabdi canal c; outer with demibranch type 4 stomareflecte ch; style-sac d, with descen conjoined ding tolamella mid-gut; only.intestine Labial

passing through ventricle of heart.

I Genus Lyonsia Turton, 1822

i Lyonsia Turton, 1822. Type species (M): Mya striata Montagu, 1815, = Mya norwegica Gmelin, 1791.

Recent, North Sea.

i Bentholyonsia Habe, 1952. Type species (OD): Allogramma (B.) teramachii Habe, 1952. Recent, Japan.

Diagnosis. Shell thin, inequilateral, equivalve, with small posterior gape. Hinge plate feeble, edentate.

I Exte in young rior andspecimens. interior nacreous. LithodesmaPeriostracum large. with radial ridges and often with adherent sand grains, particularly

I Lyonsia californica Conrad, 1837

Figure 5.52

I Lyonsia californica Conrad, 1837: 248.

Osteodesma nitidum Gould, 1853: 390.

i Lyonsia gouldii Dall, 1915: 453.

Lyonsia calif ornic a haroIdi Dall, 1915: 453.

t Lyonsia Mya striacalifornica ta Montagu,nesiotes 1815: Dall, 188, auctt 1915:., 453. non Montagu.

Material Examined. California, Santa Maria Basin, Phase II, Sta.R-8 (90 m).

I Description. Shell elongate, thin, translucent. Anterior end approximately 30% of length. Posterior

end broadly attenuate. Periostracum thin, generally light in color, with fine, widely spaced radial lime.

I Length to 35 mm.

i 171
!

I

A I

!

Figure 5.52. Lyonsia californica: A, interior of right valve; B, exterior of right valve, i

Type Locality and Type Specimens. California; types not found, possibly lost. i

Distribution. Kodiak Island, Alaska (58 ° N) [CAS, LACM], to Acapulco, Mexico (17 ° N) and in ml

the Gulf of California, in the subtidal zone to 100 m, in mud. i

Remarks. Small specimens tend to have more sand particles adhering to their periostracum. It is

possible that L. gouldii may prove to be a distinct southern species or subspecies, but no characters have I

been advanced that reliably separate it. II

Literature. Haderlie and D. P. Abbott (1980: 395), Mauer (1967c, 1969), Narchi (1968).

m

Superfamily Thracioidea Stoliczka, 1870 [ 1830]

Diagnosis. Shell aragonitic, thin, inequilateral; right valve often larger and overlapping left valve.

Umbones posterior, orthogyrate. Surface usually granulated; periostmcum variable. External ligament m

opisthodetic, parivincular, seated on nymph. Resilium in an oblique resilifer or chondmphore, supported by

lithodesma. Hinge plate weak, edentate. Interior porcellanous, chalky, or subnacreous. I

Family Thraciidae Stoliczka, 1870 [1830] I

Diagnosis. Shell aragonitic, with outer and inner homogenous layers; never nacreous, although

iridescence shows on eroded beaks of some specimens. Shell very fragile and brittle. Outline quadrate to 1

rounded, subequilateral. Right valve often more convex andoverlapping left. Posterior endgaping. Umbones II

median or posterior, perforated in some. Sculpture absent, occasionally with commarginal or oblique

undulations. Surface frequently granulated; periostracum variable. Extemal ligament, when present, l

opisthodetic, parivincular; resilium, when present, in oblique resilifer or chondrophore, supported by small II

to large laterially oriented lithodesma. Hinge plate weak, edentate. Dimayrian; anterior adductor muscle

scar elongate; posterior scar rounded. Pallial sinus present. Foot small, with byssal groove. Adult not byssate, i

Mantle lobes fused, with small pedal and fourth pallial apertures. Siphons long and separate. Ctenidia

plicate, ascending lamellae of outer demibranchs not present. Labial palps broadly triangular. Alimentary

canal with type 4 stomach; style-sac joined to mid-gut; intestine passing through ventricle of heart, i

I

172 "i
I

I Genus Thracia Blainville, 1824

Thracia J. Sowerby, 1823, ex Leach MS, nomen nudum; Blainville, 1824, ex Leach MS. Type species (M):

I Mya pubescens Pultney, 1799. Recent, North Sea. Osteodesma Blainville, 1827, ex Deshayes MS. Type species (SD Dall, 1903): Anatina myalis Lamarck,

1818, = Thracia pubescens Pulteney, 1799.

I Diagnosis, Shell ovate, thin, inflated, inequivalve; right valve larger than left. Umbones prominent,

orthogyrate; umbo of right valve sometimes perforate from contact. Posterior gape large. Ligament mostly

I external. Hinge plateProjecting weak, edentate. resilium in some; lithodesma present in many, but sometimes inconspicuous in adult.

I Thracia trapezoides Conrad, 1849

Figure 5.53

i Thracia trapezoides Conrad, 1849: 723.

Thracia kanakoffi Hertlein and Grant, 1972: 338.

I Material Examined, California, Santa Maria Basin, Phase I, BSS-94 Phase II, Sta.R-8

(96 m). (90

m).

i

shallow Descriptio radial sulcnu.s Shell and ritrdage. pezoidal, Right inflated. valve slightly Anterilarge or endr. Pustu rounded; les especial posteriloyr end prominent truncate,onset posteri off obyr

slope. Umbones wide and depressed; right umbo sometimes perforate. Periostraum dark brown. Length to

i 65 mm (Tytop1e30Lmmocalityin Pliocene and Typmaterial). e Specimens. Astoria, Oregon (Miocene); Holotype, USNM 3604.

Distribution. Cook Inlet (60 ° N), to Isla Cedros, Baja California Sur, (28 ° N), in 11 to 200 m, in

I sand and mud. Literature. Coan (1990: 30-31).

!

!

I

!

I Figure 5.53. Thracia trapezoides: A, exterior of left valve; B,interior of right valve.

I

i 173
!

Family Periplomatidae Dall, 1895 I

Diagnosis. Shell aragonitic, with prismatic outer, lenticular nacreous middle, andsheet nacre inner

layers, and with prismatic myostraca. Outline ovate to elongate; thin and fragile. Markedly inequivalve, l

with right valve more convex andoverlapping left. Umbones prominent, usually with radialfissure. Sculpture

weak, usually with commarginal undulations, rarely with radial ridges. Periostracum thin and adherent, a

frequently with cemented sand grains. External ligament obsolete; resilium in butressed chondrophore, II

usually supported by hthodesma. Mantle lobes extensively fused, with small pedal and fourth pallial apertures.

Siphons long and separate. Foot small, elongate not byssate. Dimyarian; anterior adductor muscle scar III

crescent-shaped; posterior adductor rounded. Ctemdia strongly plicate; outer demibranch with descending |

lamella only. Labial palps narrow and elongate. Alimentary canal with type 4 stomach; style-sac joined

with mid-gut; intestine passing through ventricle of heart. I

Im

Genus Periploma Schumacher, 1817

Periploma Schumacher, 1817. Type species (M): Periploma inaquivalvis Schumacher, 1817, = Corbula n

margaritacea Lamarck, 1801. Recent, Florida. I

Diagnosis. Shell ovate to elongate or rhomboidal, thin, inequivalve; right valve more inflated, i

overlapping left. Anterior end rounded; posterior end truncate. Umbones opisthogyrate, with radial fissure. u

Surface granulate or pustulate. Hinge plate weak, with large chondrophore in each valve supported by rib or

clavicle. Lithodesma usually present. Interior subnacreous, i

Periploma discus Stearns, 1890

Figure 5.54 I

PeripIoma discus Stearns, 1890: 222. II

Material Examined. California, Santa Mafia Basin, Phase I,BSS-21 (49 m); Phase II,Sta. R-8 (90

m).--Holotype (see below).

Description. Shell discoidal, equilateral; posterior end slightly produced, spout-like. Sculpture of !

maim

feeble commarginal growth lines and radial rows of pustules. Chondrophore narrow and subvertical. Length

to 45 mm. in

Type Locality and Type Specimens. San Pedro, California; Holotype, USNM 105391. U

Distribution. Monterey Bay, California (36.7 ° N) to Isla Herradura, Costa Rica (9° N), in the low

intertidal zone to 40 m, in sand. I

i@ '

Figure 5.54. Periploma discus: A, exterior of left valve; B, interiorof right valve. I

174 I
!

Superfamily Vertieordioidea Stoliczka, 1871

Diagnosis. Shell aragonitic, inflated, ovate to subquadrate, inequilateral and subequivalve. Umbones

I Sculpture usually radial; granulate or spines, rarely

anterior, incurved. surface with minute smooth.

Periostracum thin, adherent. Hinge plate edentate, frequently with 1 or 2 pseudocardinal tubercles and

occasionally with lateral teeth. Ligament opisthodetic; resilium with supporting hthodesma. Lunule usually

I developed.

i Family Verticordiidae Stohczka, 1871

Diagnosis. Shell aragonitic, with prismatic outer, lenticular nacreous middle, and sheet nacre inner

I layers. Outline ovate to trapezoidal to quadrate, inflated, inequilateral. Umbones incur,red. Periostracum thin and adherent, usually granulate. Radial sculture usually present, often of riblets or lirae, rarely with

broad undulations. Lunule well demarcated; escutcheon obscure. Ligament opisthodetic, weak; periostracum

i bridging valves; resilium in irregular resilifer, supported by lithodesma. Hinge plate feeble, sinuous, occasionally thickened, or with 1 or 2 conical pseudocardinal tubercles. Dimyarian; adductor muscle scars

subequal. Foot digitiform or laterally compressed, often weakly byssate in adult. Mantle lobes fused, with

I large pedal aperture and arenophilic radial glands on margins; exhalant and inhalant apertures with short siphonal ring with large sensory tentacles. Palhal line obscure; pallial sinus absent. Ctenidia eulamellibranch,

hypertrophied, with outer demibranch consisting of descending lamella only; inner demibranch reduced.

I The gills horizontally aligned and attached to lateral membrane, forming septum separating the exhalant chamber. Labial palps mostly small; lips enlarged forming an oral hood. Alimentary canal with large cuticular

stomach and oesophagus with strongly muscularised walls; 2 ducts to digestive diverticula; style-sac joined

I to mid-gut; intestine passing through ventricle of heart. Simultaneously hermaphroditic.

I Dalliocordia Scarlato and Genus Starobogatov, Dalliocordia 1983.Scarlato Type speandciesStarobogatov, (OD): Lyonsia1983alaskana Dall, 1895. Recent,

eastern Pacific.

I Diagnosis. Shell ovate, inflated and thin. Periostmcum with sparse radial lime. Sculpture limited to

minute commarginal striae, granules absent. Umbones prominent, prosogyrate. Ligament sunken into groove.

i Hinge plate feeble, sinuate and edentate, but with obscure central tubercle. Lithodesma large. Ctenidia absent.

I Dalliocordia a/askana (Dall, 1895)

Figure 5.55

I alaskana 1895: 703.

Lyonsietla Dall,

Material Examined. California, Santa Mafia Basin, Phase I, BSS-9 (398 m), BSS-33 (396 m);

I Phase II, Sta. R-3 (291 m).--Holotype (see below).

Description. Shell oval, inflated, thin and hyaline. Sculpture limited to distant radial lirae on

periostracum and irregular growth lines. Umbones recurved, prominent. Hinge plate feeble; lithodesma

I large. Length to 30 mm.

Type Locality and Type Specimens. SW of Sitka, Alaska (55 ° 20'N, 136° 20'W), 1569 fathoms;

i Holotype, USNM 123500.

i 175
!

!

!

!

!

!

Figure 5.55. Daltiocordia ataskana: A, exterior of valve; B, interior of right valve, i

!

Distribution. Sitka, Alaska (55° N) to Santa Catalina Island, California (33 ° N) in 291 to 3,570 m,

in fine mud. Liter I ature. F. R. Bernard (1974: 103-109), Knudsen (1970: I29-132).

Order Septebranchida Pelseneer, 1888 I

I

Diagnosis. Shell aragonitic, inequilateral, ovate to elongate. Umbones subcentral. Anterior end

rounded; posterior end truncate or rostrate. Sculpture absent or various. Periostracum adherent, usually

bridging valves. Ligament mostly external; resilium small, in vestigial resilifer, usually supported by

lithodesma. Hinge plate weak, edentate, or with more or less developed cardinal tubercles and/or lateral •

ridges. Ctenidia reduced or absent. U

Remarks. This "order," known from the Cretaceous and containing three superfamilies, is almost am

certainly polyphyletic. Early workers followed Dall (I886b) and Pelseneer (1888), who believed that a •w

continuous series of modifications were represented from Lyonsia, with typical eulamellibranch ctenidia,

through the Verficordiidae with reduced ctenidia, to the entirely gill-less Cuspidariidae. Differences in shell m

structure and anatomy, however, do not support this, and the similarities are rather due to convergence •

engendered by carnivorous macrophagy. qll

Superfamily Cuspidarioidea Dall, 1886 I

Diagnosis. Shell thin, ovate to subtrigonate; posterior end usually produced. Sculpture variable, I

surface occasionally granulate. Ligament external; small resilium supported by a lithodesma. Hinge plate I

narrow, edentate, sometimes with small pseudocardinal tubercles and lateral ridges.

I

!

176 I
!

I Family Cuspidariidae Dall, 1886

I anterior Di endagnosis. rounded; Shellposte aragonitic rior end, withdrawn homoout geneous into tuinner bularandrostrum. outer layers. Umbones Inflatedsubce in snhatral, pe, inequilateral; orthogyrate.

Subequivalve, with right valve smaller. Periostracum thin, usually dehiscent, bridging valves, frequently

i granulate. supported Sculpture by lithodesma. absent,Pallial sometimes line radial simple;or commarginal. pallial sinus ves Ligament tigial. Foot external, digitiform, sunken into directed a small anteriorly. resilifer,

Mantle lobes fused, with small anterior pedal gape. Siphons united at base and with 7 prominent sensory

I tentacles; prey. Foot exhalent digiform,sipwithhonbyssal short grove. and ever Adult sible;notinhalent byssate. siGills phonabsent; relativelypalliallargecavityand separated extensiblebytomuscular capture

septum. Labial palps minute, lips enlarged. Alimentary canal with type 2 stomach, with cuticular lining and

I muscularized walls; 2 ducts to digestive diverticula; style-sac in separate caecum; intestine passing through ventricle of heart.

i Genus Cuspidaria Nardo, 1840

Neaera Griffith, 1834, non Robineau-Desvoidy, 1830. Type species (M): Neaera chinensis Griffith, 1834.

' II Recent, China.

II Cuspidaria Nardo, 1840. Type species (M): Cuspidaria typica Nardo, 1840, = Tellina cuspidata Olivi,

1792. Recent, Adriatic.

I Diagnosis. Shell globular, thin; posterior end produced into tubular rostrum. Umbones subcentral,

inequivalve. Periostracum thin. Sculpture absent or feeble commarginal striae. Ligament with narrow, sunken

i external portion and resilium in deep, oblique resilifer, supported by lithodesma. Hinge plate narrow, with variable pseudocardinal tubercules and lateral teeth. Septum typically with 4 pairs of ostia.

I Cuspidaria parapodema F. R. Bernard, 1969

Figure 5.56

I Cuspidaria parapodema F. R. Bernard, 1969: 2232.

Material Examined. California, Santa Maria Basin, Phase I, BSS-31 (200 m), BSS-59 (216 m);

I Phase H, Sta. R-9 (410 m), PJ-1 (145 m).--Holotype (see below). Deseripfiom Shell thin and fragile, translucent. Periostracum dull, frequently with coating of

sediment. Rostrum somewhat longer than that of C. (C.) apodema. Hinge plate weak; posterior lateral tooth

I in right valve long and curved. Length to 17 mm.

Type Locality and Type Specimens. Off Redondo Beach, California (33 ° 49.5'N, 118° 26.2'W),

172 fathoms; Holotype, LACM.

I Distribution. Point San Luis, California (35.2 ° N) to Bahia Elena, Costa Rica (11° N), in 50 to 410

m, in mud.

I Literature. F. R. Bernard (1974: 41-43).

!

!

I 177
!

!

!

!

!

!

Figure 5.56. Cuspidariaparapodema: A, exterior of left valve; B, interior of right valve.

i

Genus Cardiomya A. Adams, 1864 _l

Cardiomya A. Adams, 1864. Type species (M): Neaera gouldiana Hinds, 1843. Recent, Indo-Pac_c. U

Diagnosis. Shell inflated, globular to ovate, with posterior rostrum. (The anterior portion of the

shell, apart from the rostrum, is here referred to as the "disk.") Sculpture of disk of radial riblets or lirae, U

rarely with commarginal sculpture. Right valve with posterior lateral denticle may be obsolete. Resilifer

deep and subvertical. Septum with 4 pairs of ostia and an extra lateral attachment to each valve posteriorly. I

Cardiomya pectinata (Carpenter, 1864)

Figure 5.57 I

Neaera pectinata Carpenter, 1864b: 637; 1865f: 54. I

Cuspidaria (Cardiomya) californica Dall, 1886: 296. II

Cardiomya oldroydi Dall, in Oldroyd, 1924: 33.

i

isolirata F. R. Bernard, 1969: 2231. I

Cardiomya

Material Examined. California, Santa Maria Basin, Phase I, BSS-86 (197 m); Phase II, Sta. PJ-15

(155 m), PJ-21 (143 m). n

Description. Disk ovate to elongate; rostrum long and narrow. Sculpture of sharp, well-spaced,

narrow, equal-sized radial ribs. Length to 40 mm.

Remarks. Young specimens have an elongate disk. As the animal grows, the disk becomes rounded, I

and the rostrum is proportionately longer. In northern waters, where the species attains the largest size, the

species was named pectinata, based on a small specimen, and oldroydi, based on a large specimen, while I

young specimens were identified as californica. In southern waters, the species generally does not attain as 1

large a size, and most material has been labeled californica, with only the occasional large specimen being

labeledpectinata. Occasional specimens may have radial sculpture extending onto the rostrum, and this was lip

named isolirata by Frank Bernard. There seems some merit in dividing this species into two subspecies, I

southern material having on average a more elongate disk.

Type Locality and Type Specimens. Puget Sound, Washington; Holotype, USNM 4506. m

178 I
I

I

I

I

I

I

Figure 5.57. Cardiomyapectinata: A, exterior of left valve; B, interior of right valve.

I

Distribution. Prince William Sound, Alaska (60 ° N) to Acapulco, Guerrero, Mexico (17 ° N), and the Gal_ipagos Islands (I°N), in 5 - 640 m, in sand and mud.

Literature. F. R. Bernard (1974: 50-52, 59, 61-64), Gustafson et al. (1986), Strathmann (1987:

341-342).

Acknowledgements

Marx prepared Eugne theCoanlinegreatly drawingassisted s. Jim with Blakethegreatly literature tighened and many the teleofgraphic the higher stylelevel of thediagnoses. descriptionsLaurie and

diagnoses. Marie Murphy assisted with digital imaging of several of the photographs. Many members of

SCAMIT, California inspecimens particularandDonassisted Cadien,withTony rangePhillips information. and RonDiarmaid Velarde,OFoighil loaned large provided amounts photographs of southern and

specimens of the galeommatid new genus, new species A.

I

I

I

I

I

i

179
i

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m

All, R.M. 1970. The influence of suspension density and temperature on the filtration rate of Hiatella i

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Bernard, F.R. 1969. Preliminary diagnoses of new septibranch species from the eastern Pacific (Bivalvia, I

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Bernard, F.R. 1972. The genus Thyasira in western Canada (Bivalvia: Lucinacea). Malacologia 11(2):365- in

89. II

Bernard, F.R. 1974. Septibranchs of the eastern Pacific (Bivalvia Anomalodesmata). Allan Hancock

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u

Bernard, F.R. 1976. Living Chamidae of the eastern Pacific, Bivalvia: Heterodonta). Natural History Museum

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Bernard, F.R. 1978. New bivalve molluscs, subclass Pteriomorpha, from the northeastern Pacific. Venus II

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Bernard, F.R. 1979. Bivalve mollusks of the western Beaufort Sea. Natural History Museum of Los Angeles I

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Bernard, F.R. 1980. A new Solemya s. str. from the northeastern Pacific (Bivalvia: Cryptodonta). Venus _1

39(1): 17-23. am

Bernard, F.R. 1983. New species and synonymies in the genus Nucula s.l. (Bivalvia) of the northeastern am

Pacific and Arctic oceans. Venus 41(4):251-8. I

Berry, S.S. 1947. New Mollusca from the Pleistocene of San Pedro, California-- III. Bulletins of American

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ill

Beu, A.G. 1971. New light on the variation and taxonomy of the bivalve Hiatella. New Zealand Journal

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Bloom, II S.A. 1975. The motile escape response of a sessile prey: a sponge-scallop mutualism. Journal of

Experimental Marine Biology and Ecology 17(3):311-21.

Bresciani, J. and K.W. Ockelmann. 1966. Axinophilus thyasirae gen. et sp. nov., a parasitic copepod from 1

the bivalves Thyasiraflexuosa and T. sarsi. Ophelia 3: 179-82.

Bright, D.A. 1988. A case study of histopathology in Macoma carlottensis (Bivalvia, Tellinidae) related to i_

mine-tailings discharge and review of pollution-induced invertebrate pathology -- shades of selye? i

[abst.]. Journal of Shellfish Research 7(1):151.

1

Buck, G.L. 1988. Recent findings of Chlamys hastata (Sowerby, 1843) in its southern range limit. The !

Festivus 20(10):106-7.

Burch, T.A. 1941. A survey of the west American aligenas with a description of a new species. The Nautilus ,_

55(2):48-51. i

Carpenter, P.P. 1857. Report on the present state of our knowledge with regard to the Mollusca of the west am

coast of North America. British Association for the Advancement of Science, Report 26[for 1856]: I[

159-368 + 4, pls. 6-9.

all

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I 6. CLASSCEPHALOPODA

| uy

F.G. Hochberg _

I

I Introduction

Cephalopods are soft-bodied mollusks which have a well developed head and a circumoral crown

I of mobile appendages that bear suckers and/or hooks. The mouth has a chitinous, beak-like set of jaws and a tongue-like radula with rows of teeth. An external shell occurs only inNautilus while in all other cephalopods

the shell is enveloped by the mantle and either reduced in size or completely absent. Water is expelled via a

I funne of Nautilus l from the all cmantle ephalopods cavityhave whicha aids singlein pair locomofotiogills. n andTheyeliminposasetesss waste a wellprodeduveloped cts. Withcentral the exception nervous

system and the brain is protected by a cartilaginous cranium. Large eyes and a diversity of sense organs are

I chara and other cteristiccomplex of thebehaviors. group. Extensive experimental work has been conducted in documenting both learning

The cephalopod skin is the most complex in all the mollusk groups. Numerous sacs of pigment

I (chromatophores), reflective platlets (iridophores) and refractive platlets (leucophores) are present in the surface layers of the skin. Superficial muscles allow these animals to control skin texture with a diversity of

papillae patterns. Cephalopods are capable of rapid changes in colors and patterns. They are known for the

I ability to cryptically match the color and texture of their surrounding environment. In addition, they are able to produce bold contrasting color patterns used for courtship, territorial and other behavioral displays.

Sexes are separate and in many genera either the male or female is considerably larger than the

I used to transfer to the female and fertilization is internal,

opposite sex. Spermatophores are sperm Cephalopod

eggs are heavy with yolk and development is direct. Egg capsules vary in length from 1 - 40 ram. The eggs

of benthic cephalopods are laid singly, braided into a festoon or incorporated into gelatinous 'Tmgers or

I strings" and all are attached to the substrate. Development time varies from a few weeks to months.

many

Eggs spawned by squids and sepiolids are not attended, whereas female octopuses brood their eggs until

they hatch.

I Hatchlings from large egg species stay on the bottom and immediately move or crawl away as

miniature adults. Hatchlings from benthic species with small eggs typically go into the plankton where they

can continue to feed and grow for up to several months before settling to the bottom. Metamorphosis does

I not occur nor are stages, planktonic hatchlings are "paralarvae" by some

there discrete larval These termed

workers to reflect this feature. Most cephalopods live for six months to several years at the most. The

majority are semelparous and die after spawning or brooding their eggs.

I Cephalopods are active predators that feed mainly on crustaceans, other mollusks, worms and fishes.

In turn they are a major component in the diet of toothed whales, pinnipeds, marine birds, and larger fishes,

i including sharks. Offthe west coast of North AmericaLoligo opalescens are caught for human consumption on a commercial basis. Several octopus species are used for food or bait along coastal California but do not

support a sustainable fishery.

I

_ Department of Inver_ebrale Zoology Santa Barbara Museum of Natural History, 2559 l_esta gel Sol Road,

I Santa Barbara, California 93105 USA

i 189
U

Approximately 800 species of living cephalopods are currently recognized. They are exclusively •

marine and occur in a wide diversity of habitats, in depths from the surface to over 5000 m. Adults range

from about 2 cm to over 20 m long and weigh from 1 g to over 1000 kg. •

Cephalopod systematics is currently in a state of flux. The earlier monographs by Berry (1912, !i

1949, 1953a), Pickford (1964), Voss and Pearcy (1990) and others dealing with the west coast fauna are in

need of considerable revision. Much of the species specific work cannot be adequately addressed until the •

genus group names have been revaluated and rediagnosed using consistent, modem terminology.

Collection and Preservation I

Deep water benthic cephalopods traditionally are collected using commercial or scientific bottom n

trawls. More recently these animals have been observed live and then collected either by remote or manned II

submersibles. In shallower depths, octopuses are collected by divers using nets or other devices. A variety

of irritants, such as vinegar, ammonia, copper sulfate, or quinaldine, often have to be used during capture to IBm

cause specimens to emerge from their dens in rocky areas. m

Following collection, animals should be kept alive in running sea water or placed in ice chests filled

with chilled sea water until they can be studied or preserved. For identification purposes it is important to

examine animals while still alive to record characteristic skin textures (papillae patterns) and color patterns. ID

Whenever possible color photographs should be taken of live animals for comparison with preserved

specimens. If animals are dead when they arrive on deck or following capture they should be chilled but not •

frozen until they can be fixed. If at all possible, specimens should not be frozen because that process destroys HI

a number of key characters used for identification.

elm

to their large size, heavy musculature and lack of skeleton, cephalopods, especially octopods, i

Due

are notoriously difficult to fix and preserve. Animals should be relaxed by slowly adding ethyl alcohol to

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their sea water. Other narcotizing agents also may be used such as magnesium choride. When the animal no mm

longer responds to prodding it is ready to be fixed in 10% buffered formalin. Cephalopods normally are

fixed for periods of a day to several days depending on their size. In the case of very large specimens, the

a

buffered formalin should be injected into the body cavity to enhance the fixation of internal organs.

Fixation should be done in large pans that will accommodate the entire length of the specimen I

being treated and allow it to be completely immersed. Only the smallest species should be fixed in jars

because this process may distort specimens, especially large octopuses. Also, once tissues harden specimens I

they often cannot be removed without breaking the jar. Small, live squids and sepiolids can be placed 1

directly into 10% formalin without narcotization. The contractions of the body pull fixative into the mantle

i

cavity and result in excellent preparations. At the time of fixation, if animals are completely muscle dead, I

they will harden into postures which induce distortions of body proportions, especially arm lengths. Unless •

u

material is to be used for DNA studies they should not be fixed in alcohol. If DNA study is anticipated a

portion of each specimen, such as an arm tip or fin, should be cut off, prior to fixation, and placed in 95%

ethyl alcohol. I

Following fixation, rinse specimens in fresh water for at least 24 hours to remove most of the

formalin. Rinse briefly in alcohol prior to final preservation. The majority of cephalopods are preserved for I

long term storage in 70% ethyl alcohol (preferred) or 45-55% isopropyl alcohol. Gelatinous species, such |

as the cirrate or finned octopods, should be retained in 5% formalin for long term storage. Specimens should

be positioned with the body down and the arms up so bubbles are not trapped in the mantle cavity. Small to

medium size specimens are stored in vials and small jars. Glass or plastic buckets with snap lids are used for |

medium to large specimens. Extremely large specimens must be stored in stainless steel, plastic or fiberglass

tanks. For additional details and information on fixation, preservation, and curation of cephalopods see am

Roper and Sweeney (1983). I

190 |
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I Laboratory Study

I specimens. DepThending e idenontification the natuofrepreofserved the study, cephalopods live cephalopods typically involve often are s a easier numbertoofidentif countys,than measpreserved urements

and indices. A list of standard features used in morphometrics is provided below.

I A more detailed resolution of species and relationships involves the study of intemat anatomy. Features such as the configuration of the digestive and reproductive tracts, and the morphology of beaks,

radulae and spermatophores should be characterized. Resolution of some characters, such as the funnel

I organ, often are aided by the use of aqueous methylene blue to enhance visibility. Whenever possible additional elements such as the size and shape of spawned egg capsules should

be noted because clutches of eggs occasionally are trawled up separate from the adults. The presence of

I spawned indicates the of a species in a given region and helps to advance our understanding

eggs presence

of spawning seasons and habits of cephalopods found along the west coast.

i Roper and Voss (1983) provide guidelines for the description of cephalopods. Their publication also is helpful in understanding procedures and terminology used in identifying squids, sepiolids and

octopuses.

I Terms for Measurements and Counts

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AL. arm length I_W. mantle width

I longest to arm lengths (by on each arm

Formula. shortest S Count. number of suckers

arm pair) Sp Count. number of spermatophores in

I AW. arm width storage sac

IlL. diverticulum length SpL. spermatophore length

I E Count. number of mature ovarian or SpRL. spermatophore reservoir length

spawned eggs TCS Count. number of suckers on each tentacle

EL. length of chorion capsule of egg club

I EStL. length of egg stalk TL. total length

G Count. number of gill lamellae per outer TOL. length of terminal organ complex (=

I demibranch penis)

GL. gill length TW. total weight

I HW. head width WD. web depth

ML. mantle length WD Formula. deepest to shallowest web depths

I (by sector)

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I 191
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Indices (percentages) I

AMI (arm mantle index) = AL + ML x 100 SDIe (enlarged sucker diameter index) = diameter I

largest enlarged sucker + ML x 100

AWl (arm width index)= widest arm + ML x 100

EL1 (calamus length index) = CL + LL × I00 SDled distal (SDIe, distal field, in cirrates) = SDe in I field + ML x 100

CiLI (cirri length index= CiL + ML x 100 SDIep (SDIe, proximal field, in cirrates) = SDe in

D/AS = diameter (lateral arm span), measured proximal field + ML x 100 I

from arm tip to arm tip SDIn (normal sucker diameter index) = diameter

DLI (diverticulum length index) = DL + TOL x largest normal sucker + ML x 100 I

!00 SpLI (spermatophore length index) = SpL + ML x

ELI (egg capsule length index) = egg capsule 100 I

length + ML x i00 SpRI (spermatophore reservoir length index) =

FFLI (free funnel length index) = FFL + FL x 100 SpRL + SpL x 100

FLI (funnel length index) = FL + ML x 100 StyLI (stylet length index) = StyL + ML x 100 I

FOLI (funnel organ length index) = FOL (median TCLI (tentacle club length index) = TCL + TL x

limb) + FL x 100 100 I

HWIw (head width index) = HW + MW x 100 TLI (tentacle length index) = TL + ML x 100

LLI (ligula length index) = LL + length TOLI (terminal organ length index) = TOL + ML I

hectocotylized arm x 100 x 100

MWI (mantle width index) = MW + ML x 100 WDI (web depth index) = deepest web sector + I

OAI (opposite arm index) = length hectocotylized length longest arm x 100

ann + length opposite ann x 100 !

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I

I

I

I

192 I
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I Glossary

I Accessory nidamental #ands. (see nidamental Cirri. Elongate, fleshy, f'mger-like projections glands), along the lateral edges of the oral surface of

the arms, especially in cirrate octopods.

Aeetabulum. The lumen of a sucker; muscular

I contraction produces the suction, single central projection on

Cone. The the

rachidian tooth (see cusp; = mesocone).

Anal flaps. A pair of fleshy flaps or finger-like

I papillae species which that arise lackatinkthealsosideslackof the analanflaps, us; Copulato of the ry hectocotylized organ. The modified arm ofgroove- maturelikemaletip

octopuses; consists of a calamus and ligula

i Arm formula. Comparative length of the arms (= end organ). expressed numerically in decreasing order,

e.g., 3.2.4.1. Corneal membrane. The thin, transparent skin

that covers the eyes of myopsid andsepioid

I Beak. present A pair of horny, parrot beak-like structures cephalopods. in the mouth; consists of an upper

and lower beak (see buccal mass). Cusp. One or more lateral projections on each

I Buceal lappet. Small, triangular flaps formed by siasymmetri de of thecal ralychiarr dianange toodth;(seesymcomneetri ). cally or

the tips of buccal membrane and the

muscular membrane supports; may bear Daetylus. The distal or terminal section of the

I suckers, tentacle club, often characterized by suckers

of reduced size.

Bueeal mass. The muscular mass associated with

I thande mouth anteriowhich r salivarcontains y glandsthe, beaks, mdula, Festooneggs. . A braided string or strand of octopus

Buceal membrane. Thin web of tissue that Finger. A sausage-like capsule containing eggs of

I encircles the mouth in squids, reinforced loliginids.

by

6-8 buccal supports. Fin lobe. The portion of each fin that protrudes

I Buceallappsucke ets,rs. Small suckers on the buccal ante ttachmriorlyentfrofomththe e fiann toerior the pmantle. oint of

Calimns. The conical projection on the copulatory Fins. The pair of muscular flaps that arise along

I of octopods at the proximal terminus the dorsolateral surface of the mantle of organ

of the spermatophore groove, distal to the squids, cuttlefishes, vampyromorphs, and

last sucker (see copulatory organ, ligula), citrate octopods; used for locomotion,

I Chromatophores. Pigment-filled organelles in

steering and stabilization.

the skin of cephalopods; consists of Fin Support Cartilage. Cartilaginous support for

I cytoel controlastithat c sacs collectively under individ provideual the nervous fins V-shainpedcirrarodte octopods, or is saddle-shaped consists of(=a sU- hellor

background color and color patterns in vestige, pteropallial cartilage).

i cephalopods. Funnel. The ventral, conical tube through which Circumoral appendages. The eight arms and two water is expelled from the mantle cavity

tentacles that arise fxom the head and during locomotion and respiration.

I encircle the mouth of cephalopods.

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I 193
!

Funnel locking cartilage. The cartilaginous KiilUker organs. Minute, bristle-like structures

socket-like pad that contains a variously that cover the skin of planktonic octopod

shaped groove, pit, pocket or depression on paralarvae, n

each ventrolateral side of the posterior part Lateral ridge. A ridge or fold of skin aroundthe

|

of the funnel that locks into the mantle

component of the apparatusduring lateral mantle of some octopods.

locomotion (see mantle locking-apparatus). Ligula. The spatulate to spoon-shaped structure at U

the tip of the hectocotylized ann in male

Funnel organ. The superficial pad or patch of

glandular tissue on the internal surface of octopods (see calimus, hectocotylus). I

the funnel; the shape is genus or species Mantle. The fleshy tubular or sac-like body of

specific (= Verrill's organ), cephalopods; contains the viscera; provides

I

Funnel valve. The semilunar muscular flap on the propulsion through jet-like expulsion of i

inner, dorsal surface near the distal opening water (see mantle cavity).

of the funnel. Mantle cavity. The hollow part of the mantle aim

Gill lamellae. The leaf-like, convoluted which contains the gills and viscera. 1

components of the gill through which gas Mantle locking apparatus. The snap-like ridge

exchange occurs, and socket components which connect the 1

Gladius. The feather-like or rod-shaped chitinous mantle dorsally to the head and/or venlrally

support structure in the dorsal midline of to the funnel. Three components may be

present: 1) nuchal or head locking-cartilage i

squid (=pen).

(sepiolids); 2) mantle locking-cartilage

l:leetoeotylized arm(s). One (or more) arm(s) of (button, all squids) and 3) funnel lockingmale cephalopods modified for transfer of cartilage (socket, all squids). The apparatus n

spermatophores to the female; modifications serves to lock the mantle to the funnel and i

may involve suckers, sucker stalks, head during locomotion, so water is

protective membranes, or trabeculae. Either expelled only through the funnel and not •

the entire arm may be modified, or only its around the mantle opening

distal portion. Functions as the copulatory or

intromittent organ (see calimus, ligula; = Mantle locking cartilage. The button-like n

hectocotylus, = nuptial arms), cartilaginous pad variously shaped as a

ridge, knob or swelling on each side of the

Inftmdibulum. The exposed flat ring that ventrolateral, internal surface of the mantle 1

functions as the adhesive surface of a that locks into the funnel component of the •

I

sucker, apparatus during locomotion (see mantle

locking-apparatus).

Ink sac. The organ that manufactures and stores •

the ink in cephalopods; the sac is embedded Marius. Central portion of the tentacle club II

in the digestive gland, it lies along the between the dactylus distally and the carpus

intestine and empties via a duct into the proximally. •

rectum. Nidamental glands. Two large, cylindrical glands II

Keel. (A) A flattened, membranous muscular and 2 smaller accessory glands in mantle imi

extension along the aboral surface of some cavity of female squids; secrete gelatinous n

arms to render them more hydrodynamic; material which envelopes the fertilized eggs

I

(B) one or two expanded muscular as they are extruded.

membranes on the tentacular club of some

groups. Functions to streamline and support

the arms and tentacles during swiming (=

swimming keel). I
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I Nuchal locking cartilage. The oblong, Raehidian tooth. The central tooth in a row of 7

cartilaginous pad in the posterior dorsal teeth in the radula; a heterodont rachidian

i surface articulatesof thwith e heada complimentary of most squids;structure t

lateral ooth hascusps a large maycentral be present cone(see andcone, 1 or more cusp,

on the inner surface of the anterodorsal part radula).

i of the mantle (see mantle locking- apparatus). Raehis. The thickened central axis that usually

extends the entire length of the gladius. Free

Oeellus. A pigmented spot or patch, usually rachis is the portion that does not support

I consisting of a central locus and the vanes (see gladius, vane). concentrated dark chromatophores; with one

Radula. The chitinous, ribbon-like structure in the

or more concentric rings of chromatophores

I or iridophores, mouth of cephalopods containing transverse rows typically composed of: 1 rachidian

Olfactory organ. A sensory pit, bump or papilla- tooth (centrally located); 2 lateral teeth and

i like protuberance on the posterolateral 1 marginal tooth (on each side); 1 marginal surface of each side of the head; function plate (at the end of each row of teeth) (see

presumed to be olfactory, rachidian tooth).

I Pallialmantle aperature cav . The slit-like opening to the Secondary web. The narrow membrane that ity, situated on the ventral surface connects the primary web to the arms in

of the mantle, some cirrate octopods.

I Papillae. Soft, muscular, finger-like extensions of Seminal recepticle. A bulbous structure in the

the skin. buccal region of some female cephalopods

I Paralarva. A young cephalopod of the first post- (e.g., loliginids), for the retention of viable sperm until they are required for fertilization

hatching growth stage that is pelagic in (= bursa copulatrix).

near-surface waters and that has a distinctly

I differe conspecific nt moindividual de-of-life s,from that of older Shell Vgladi estige. us. see fin support cartilage, stylets,

Patch and groove system. The reticulate pattern Spermatophore. A tubular structure

I in the skin, the dorsal manufactured male for

seen especially by cephalopods

mantle, of some species of octopuses, packaging sperm.

I Pedicel.suckAershoinrt, squids cylindarical nd cutstletalkfishethas,t supports a Spermatophore usually in thepadman . A tlfleeshy cavitypatofch somof tissue, e female

cephalopods (e.g., loliginids), to which

i Photophore. Simple or complex light organs that spermatophores adhere after mating until produce bioluminescence by intrinsic (self- fertilization occurs.

generated biochemical reaction) or extrinsic

(bacterial) means. Spermatophore sac. The elongate, membranous

I Poc container at the terminus of the the male

ket. An open depressionin the anteroventral

reproductive tract that stores mature

surface of the head of sepioids into which spermatophores (= Needham's sac).

• the feeding tentacles are retracted when not

II in use. Stylets. A pair of small keratinized or calcified

rods embedded in the wall of the dorsal

Protective membrane. Thin web-like fold of the

I integument along the lateral angles of the mantle of some octopods. oral surface of the arms and tentacle clubs

lateral to the suckers, typically supported by

I trabeculae (see below).

I 195
!

n

Suckers. Muscular, suction-cup structures on: a) Tentacle club. Terminal portion of a tentacle; •

the oral surfaces of the arms; b) the tentacle armed with suckers (or suckers and/or

clubs; and rarely c) on the buccal membrane hooks), used for capturing prey. •

of cephalopods. Suckers may be stalked, Ii

placed on muscular rods that contract Terminal Organ. The duct and organ complex at

(squids and cuttlefishes); or sessile, containsthe distalaenddiverticulumOf the male reproductive tract; I

embedded without stalks on the oral surface (= penis). •

of the arms (octopuses) (see acetabulum, Trabeeulae. Muscular rods that support the " i

infundibulum), protective membranes on the arms and m

tentacle clubs of squids. Sucker ring. Chitinous ring that encircles and

provides rigidity to the opening of suckers Vane. Thin lateral expansion of the gladius that

of squids and cuttlefishes; may be smooth, arises from the rackis (see rachis), n

serrated or denticulate.

Web. A thin membranous sheet of skin that

Tail. The posterior extension of the mantle, extends between the arms of many am

frequently elongate. Fins or tapered cephalopods (especially octopods), giving |

terminations of fins may extend posteriorly an umbrella-like appearance when the arms

along the tail. are spread out. •

Tentacles. Elongate, stalked circumoral Web formula. Comparative depths of the web _ '

appendages of cuttlefishes and squids used sectors expressed alphabetically in

to capture prey; distal ends contain clubs decreasing order, e.g., B.C.D.A.E.

with suckers (or hooks); tentacle stalks

usually devoid of suckers.

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196 |
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I Key to the Orders of Cephalopoda

I 1A. Ten circumoral appendages (8 arms plus 2 tentacles); arms with stalked suckers; body rounded to [ elongate with fins; with an internal shell (gladius or pen) .............................................................. 2

1B Eight circumoral appendages; arms with sessile suckers; body ovoid, not elongate ........................

I ................................................................................................................................. Order Octopoda

I 2A Tentacles retractile into small pockets between arms 3 and 4; eye membrane absent; mantle rounded, less than 50 mm long; mantle free all around; fins semicircular, almost as long as mantle, with

broad free lobe; arms short, circular in transverse section; dorsal arms hectocotylized ..................

I ................................................................... Order Sepiolioidea; Family Sepiolidae; Rossia pacifica 2B Tentacle not retractile into pockets; eye covered by transparent membrane; tentacle clubs narrow

and without fixing apparatus, suckers large and in 4 rows; arms with 2 rows of suckers; arm lengths

I unequal, ventral pair long and broad; left ventral arm of male hectocotylized; rims less than half mantle length, fins triangular, length equal to width; mantle elongate and tapered, length not exceeding

150 mm; mantle attached; arms long, angular in transverse section ................................................

I Order Teuthoidea; Family Loliginidae; Loligo opalescens

!

i List of Species

Family Sepiolidae

I Rossia pacifica 1911

Berry,

Family Loliginidae

I Loligo opaIescens Berry, 1911 Family Octopodidae

Benthoctopus leioderma (Berry, 1911) new combination

I Benthoctopus robustus Voss and Pearcy, 1990

GraneIedone boreopacifica Nesis, 1982

I Octopus dofleini (Wiilker, 1910)

Octopus rubescens Berry, 1953

i Octopus californicus (Berry, 1911)

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I 197
!

Description of Species i

im

Family Sepiolidae Leach 1817 i

Diagnosis. Mantle short, broad, sac-like, stubby; fins separated, rounded; mantle locking apparatus i

simple, straight; shell, if present, chitinous; ink sac present or absent; light organ on ink sac present or I

absent.

Subfamily Rossinae Appelloff 1898 I

Diagnosis. Anterior margin of dorsal mantle free; articulating with ovate nuchal cartilage; gladius ml

present; one or both dorsal arms hectocotylized; web relatively narrow, not forming sheath around tentacles 1

at base; glandular luminescent organ associated with ink sac absent; fins moderate to large size, auriculate

in front.

Genus Rossia Owen, 1834 i

Type Species: Rossia palpebrosa Owen, 1834.

Diagnosis. Animals robust. Web greater than 1/2 arm length between arms 3 and 4. Sessile arms II

short; suckers spherical, arranged in 2-4 rows; greatly enlarged suckers absent in middle part of arms. Ill

Tentacles entirely retractile; clubs wide, not bent; suckers on clubs, medium to large size, typically arranged

in 6-12 rows. Both dorsal arms hectocotylized; suckers reduced in size; protective membranes on modified i

parts of hectocotylized arms welI developed, separated from sucker stalks by deep groove. Gladius much I

reduced. Ink sac present. Anal flaps present. Papilliform glands on sides of rectum absent. Spermatophores

with thick, non coiling sperm cord. I

Rossia pacifica Berry, 1911 !1

Figure 6.1 i

Rossiapacifica Berry, 1911:591.--Berry, 1912a: 290-293, pls. 41(figs. 1-6), 42(fig. 1),43(figs. 2-4), 44(figs. Ill

1,5).---Sasaki, 1914: 598-599; 1920:188-189. --Berry, 1921: 353.---Sasald, 1929: 154-157, texffigs. 1

92-94, pl. 16(figs. 3-6).--Johnson and Snook, 1927: 579-580, fig. 679. --Kondakov, 1941: 217,

219, fig. 3. --Akimushkin, 1965: 156-159, figs. 45, 46. --Taki, 1965: 314. --Mercer, 1969: 270. •

Iverson and Pinkas, 1971: 105, fig. 50.---Okutani, 1973: 92-93, textfig. 22. ---Okutani, 1975: 28. -- II

Okutani, 1977: 40-41, fig. 20. ----Okutani, 1980: 24-25, fig. 22. --Hochberg and Fields, 1980: 431-

432, pl. 134(figs. 17.1a, b).--Taki, 1981: 240.---Clarke, 1986: 217, figs. I16A, 120A.--Okutani •

et. al., 1987: 85, pl. 25(figs. A-C). --Nesis, 1987: 125, fig. 26K, L.--Hochberg, 1987: 293, fig. Ii

I4.6.

? Rossia sp. --Berry, 1912a: 417. 1 

Rossia borealis Sasaki, 1913:243.

Material Examined. California: --1 female (immature), 15 mm ML; Ventura Co, Pt. Mugu, off •

Mugu Pier, 30-50 ft [9-15 m]; coll. Conboy and party, 5 December 1962; SBMNH 51570 [ex MacGinitie II

collection]. --3 males (submature and mature), 21-29 mm ML; Santa Barbara Co, 2 mi S of Santa Barbara,

200 ff [61 in]; coll. F.G. Hochberg and P.H. Scott, station 1, 29 September 1986; SBMNH 60036. --1 •

female (mature), 40 mm ML; Santa Barbara Co, 1.5 mi S of Santa Barbara, 29 fm [53 m]; coll. F.G.

Hochberg and P.H. Scott, station 2, 29 September 1986; SBMNH 60018. --2 females (immature and

submature), 34 and 36 mm ML; western Santa Barbara Channel, off Ellwood Beach, 34°20'N, 119°50'W, i
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I 36 fm [66 m]; coll. S. Anderson, 27 June 1979; SBMNH 42487. --2 females (submature and mature), 35

and 44 mm ML; western Santa Barbara Channel, off Naples, 110-120 fm [200-220 m]; coll. R. Hazard, FI

I VandEagle 46 mmB, ML; 10 September western Santa 1974;Barbara SBMNHChannel, 44065 off [beakNaples, voucher]. 120 fm--2[220females m]; coll. (submature R. Hazard, andFmature), /V Eagle 39B,

24 August 1974; SBMNH 44066. --1 female (mature), 45 mm ML; western Santa Barbara Channel, off

i Hendrys Beach, 61 m; coll. D. Ibara and F.G. Hochberg, 27 May 1967; SBMNH 60039 [dicyemid voucher]. --1 male (mature) + 1female (submature), 30 and 35 mm ML; Santa Cruz Island, off W end of island, 110

fm [201 m]; coll. P. Brophy, F/V Eagle B, 1967; SBMN-H 47505.

I Andrea, Oregon:--Lincoln station 1498-42, 9 August Co., 351942; mi WSBMNH of Depoe60013 Bay, [44°47.8'N, ex AHF/USC]. 124_23.7'W, --5 males110-128 (mature)m;26-30 coll. Rmm/V

ML, off Coos Bay, 65 fm [119 m]; coll. F.G. Hochberg, 20 July 1965; SBMNH 47504.

I DuwamishWashington: River, --5 females (immature - mature), 30-45 mm ML; Seattle, Elliott Bay, off mouth of 45 fm [82 m], coll. R. Anderson, CIVChasina, 5 June 1992; SBMNH.--1 clutch spawned

eggs; Seattle, Seattle Aquarium; coll. R. Anderson, 17 July 1993; SBMNH.

I 60029. Alaska: --2 females (submature), 22, 35 mm ML; Port Dick; coll. R. Baxter, 25 June 1985; SBMNH

Description. Body moderately large (TL to 105 mm; TW mature males 10-15 g, mature females

I 20-30 g). Females longer, more robust and heavier than (ML mature males mm, mature

males 25-35 females

25-55 mm). Mantle firm and muscular, short; shape subcylindrical, longer than wide (MWI 63-100); dorsoventrally flattened, rounded posteriorly; mantle in males widest anteriorly, in females width uniform. Anterior

I dorsal mantle margin free short angular medial projection; ventral margin weakly concave.

with Mantlelocking apparatus small; nuchal cartilage ridge- like plug, longer than funnel socket, slightly curved, twice

as long as wide, shape elliptical, stongly narrowed posteriorly; funnel cartilage three times as long as wide,

I with raised sides located either side of funnel shape elongate-rectangle prominent margins, parallel, one on

base. Fins large, muscular, almost as long as mantle (FiLI 60-72); shape semi-lunar or subcordate, broad, 1/

2 to 2/3 as wide as long (FiWI 110-130-180); anterior lobes free, do not reach edge of anterior mantle

I margin; attached to middle of body, more or less oblique to general body plane.

Gladius slender, much shorter than mantle; shape lanceolate in males, more spatulate in females;

vane thin and delicate, moderately wide, starts near middle of rachis and continues beyond tip of rachis,

I bluntly rounded posteriorly.

Head large, narrower than mantle (HW188-112); dorso-ventrally compressed.Eyes large, prominent,

I oval; Funnellower stout,lidsthick free,walled; orbit semi-l broadunatar,base, lids concent slender,ric; conical, lacryrnal trunpore cate distinct. at apex; Olfactory free for most papillae of length, prominent. often

projects beyond base of ventral arms. Funnel valve large, rounded, located midway between anterior tip of

i funnel with organ and free margin of funnel. Funnel organ prominent, fleshy; single large median V-shaped pad apical projection and 2 broad, elongate-pyriform lateral pads. Anal flaps long, appear flattened or

blade-like. Buccal membrane thick, 7 lappets present without suckers; ventral 2 lappets originate very close

i together;Arms marginal mediumprojections length (ALI undiscernable. 42-58; AMI 86-120-128), stout; lengths unequal, arm pair 1 always

shortest, formula typically 3.2.4.1 or rarely 3.4.2.1; aboral surface of arm rounded, sucker bearing surface

I flat. distallyArmonsuckers all arms; arranged suckerinnumber densely about crowded80. diagonal Pedicles rows; short. 3-4Suckers per rowspherical medially;to 2subglobular, per row basaUy oblique; and

sucker openings minute, typically circular in males, occasionally narrow and slit-like; chitinous tings well

I developed essentially with alikesmooth, on all arms) entire margins. Suckers smaller (SDIn 3.3-4.2) and more uniform in size (arrangement in females than in males (SDIn 6.4-7). In males suckers distinctly enlarged in

mid-portion of arm pairs 2-4; largest and most densely packed on arms 2 or 3. On arms of both males and

i females marginal suckers larger than mesial suckers and suckers in middle of arms largest, gradually

I 199
!

decreasing distally; size subequal in all rows at same point on arm. Web well developed, broad or deep I

between arms 3 and 4, covers base of tentacles; very shallow to rudimentary between other arms, absent

between venlral arms. Swimming keels present along aboral surface of all arms, especially prominent on •

arms 3; keel on arms 4 extends from tentacle sheath to arm tip. Protective membranes weakly developed, 1

very narrow, associated with pedicle bases of suckers.

Hectocotylized arms - dorsal arm pair in mature males; arms short (HcLI), often strongly recurved n

dorsally. Suckers on hectocotylized arms greatly reduced in size (HSDI 2.2) 113as large as those on lateral

arms; 4 suckers per row basally, reduced to 2 per row distally; sucker number about 65-75 per arm. Pedicle

bases enlarged and transversely compressed to form series of prominent transverse folds or ridges. Protective •

membrane narrow on inside of dorsal arms, wider and more prominent aborally; ventral protective membrane

broad on outside of arms, extends distally along arm more than 1/2 distance to tip; deep longitudinal groove

defined by membranous fold along 2/3 of outside ann length. In mature males, thickened ridge of glandular •

tissue on inside lateral edge of each dorsal arm, extends about 1/2 length of ann in mid region. |

Tentacles retractile into shallow pockets between arms 3 and 4; 2-3 times longer than body when

extended (TLI 173-200-333); oral surface of tentacle stalk flattened with distinct medial groove, aboral n

surface rounded; stout, as thick as arms. Tentacle clubs well defined, elongate (TCLI), slightly wider than

stalk, crescent-shaped to lanceolate; sucker beating surfaces bordered with 2 protective membranes - ventral

membrane narrow, marginal and dorsal membrane broad, originates proximal to club and extends to dorsal •

tip, flap absent. Tentacle club suckers arranged in 6-8 oblique rows medialIy and 2-3 longitudinal rows at

base. Suckers minute, crowded; sizes unequal; largest located near base of club, gradually decreasing in size

ventrally and distally; cup-shaped, flattened on one side, with wide apertures; chitinous rings with numerous II

(about 45) small blunt teeth; surrounded by broad papillate band. Pedicles moderately long.

Gills long, narrow, leaflets thin; with 22-25 lamellae per outer demibranch. Tip of gills not attached

to mantle wall. n

Beaks small, robust; upper beak roslrum about 1t3 hood width; lower beak - with pronounced tooth

or projection on shoulder, rostral length about 1/4 hood length, crest walls parallel without posterior

indentation. Radula with 7 teeth; rachidean tooth - without lateral cusps; lateral teeth 1 and 2 - similar in 1

shape, tall, narrow, with very high cusp; marginal tooth - elongate, saber-like.

u

Female reproductive tract - single oviduct on left side. Nidamental glands very large, similar in •

size, in contact along entire inner surfaces; accessory nidamental glands present, small, appear darker at I

maturity. Spermatophores deposited on left side in funnel pocket or nuchal pocket. Spawned eggs large,

nearly transparent, with pointed apex (capsule 9 mm long, 5 mm wide). Hatchlings large, benthonic, n

Male reproductive tract; terminal organ - elongate, tubular, thin walled. Spermatophores small |

(length 6-16 mm; SpL142-48); ensiform; head highly convoluted; sperm whorls not spirally coiled; reservoir

stout (SpWI 37-48); unarmed; maximum number present 65-85 (typically between 20-30). •

Skin smooth, without papillae. Color in life dark red-brown to violet, darker dorsally on head, arms

and mantle; ventral mantle and underside of fins lightly pigmented to almost white; occasionally appearing

light opalescent gray-green or iridescent blue or green. Single median dorsal mantle dark spot and dark eyes n

present in dymantic display. Color in alcohol brownish buff, densely punctate dorsally and on f'ms and to

lesser degree ventrally, laterally and on underside of fins with purplish chromatophores; funnel entirely

unpigmented. I Type Locality and Type Specimens. Pacific Ocean - Alaska, [Alexander Archipelago], vicinity of

Yes Bay, Behm Canal, [1mi off Cannery Point], 39-45 fm [71-82 m].

Holotype: USNM 214323 [SSB 21]; no longer extant, n

Paratypes: ---8 specimens; from same lot as holotype; USNM 214323 [SSB 21], no longer extant.--

1M (immature) + IF (immature), 28 and 28 mm ML; from same lot as holotype; CAS1Z 018796 [SSB 21; n

SU 2125; CASIZ type nos. 495 and 496]. I
!

I Distribution. Boreal; wide spread in North Pacific from Korea, Japan and Sea of Japan north through

Sea of Okhotsk, Kurile Islands and SE Kamchatka to Aleutian Islands, Bering Sea, Gulf of Alaska south to

I range southernfroCam liforni 10-250a m(34; °Nin )

th. eNerefic westerninNoshall rthowPacific coastalfromwaters; 100-600 depthsm.ofThe captanimals ure inthetypicall easterny live Nortburied h Pacifiinc

soft sand and mud bottoms.

I Ocean. Etymology. Specific name recognizes the species abundance and distribution in the North Pacific

Common Name. North Pacific bobtail squid

I Also referred to the short and Snook 1927 197

as squid (Johnson ); stubby squid (Brocco 1;Hochberg

and Fields 1980; Anderson 1991); Pacific bob-tailed squid (Tomiyama and Hibiya 1978); bottle-tailed

cuttlefish (Okutani 1980); bob-tail cuttlefish (Okutani et al. 1987).

I Biology. In spite of its abundance in the Eastern North Pacific relatively little is known about

Rossia pacifica. The biology has been extensiverly studied in Puget Sound (Washington, USA and British

i Columbia, Canada). The species was first studied in detail by Brocco (197I). Brocco analyzed the morphometrics of specimens collected in Canada off Vancouver Island. He described the beaks, radula,

male and female genitalia for the first time. Sasaki (1913, 1929) described in detail Japanese specimens

identified as the same species. The life history was documented by Summers (1985a, b) and Summers and

I Colvin (1989).

Rossia pacifica is semelparous and has a 2-year life cycle; 18-19 months from hatching to death and

I 5-6 samples. monthsGrowth of embisrydimorphic onic develand opmenaccelerates t (Summers, with 1985). age. Ovarian Typicallydevelopment two age classes beginsareatpresent 24 mm inMLfieldin

females and 50% of males are mature with spermatophores at 26 mm ML.

I indicatedRossia that thelivessquidin lospends w densilong ties pewherever riods duriitngoccurs the dayalongon thethe cbottom oast. Brcovered occo (1971) in sand. and Sand othersgluing have

behavior, typical of other sepiolids, has been observed but it is brief and transient. The squid emerge from

I the by 6substrate months and of agebecome (Summers activeandshortly Colvin, after1989). sunset. Nocturnal or crepuscular activity pattern well developed

Polychaete worm, mysids and caprellid amphipods utilized by juveniles. Shrimps (especially

I PandaIus maintaineddanae easily) ainndtheother labora smaltory. l crustaceans preferred by adults (Brocco, 1971; Summers, 1985). Can be

Mating has been described by Brocco (1971) and Anderson (1991). During copulation the male

I orients his body ventral and posterior to the female and grasps her with the lateral and ventral arms. The dorsal hectocotylized arms are wrapped over the openings of the pallial cavity of the female. Spermatophores

are deposited on the left side in the funnel pocket or nuchal valve pocket. In mated females the sperm bulbs

I (spermatangia) are evident just beneath the colorless skin in the nuchal region.

Eggs are laid when water temperatures warm to 11°C. The ovary of unspawned females contains

about 130 mature eggs, each measuring 4-5 mm in diameter (Summers and Cotvin, 1989). The capsules of

I spawned eggs are spherical shape measure mm length mm They are nearly

in and 8-9 in and 5 in width.

transparent or colorless. They are attached to the substrate by a disk at one side while the other end of the

capsule is drawn out into a point (Fig.). Clutches of 25-50 eggs are laid at one time which represents about

I 35% of the females body weight. The spawning be repeated over a several week period. The

process may

egg mass from a single female may contain 80-100 eggs attached in a single mass 2-3 layers of eggs deep.

Spawning occurs in tate spring and early summer (April - June) or late summer and fall (August - October).

I Adults die in late spring to early summer within days of spawning.

!

I 201
Figure 6.1 Rossia pacifica: A, ventral view; B, male - oral view of right arms. (after Berry, 1912a). I

Vitellogenesis and development of oocytes have been examined in Rossia pacific from the western •

North Pacific (Aisenshtadt, 1969, 1971). The ultrastructure of spermatozoa ofR. pacifica from Puget Sound

was studied by Fields and Thompson (1976). •

Development takes 5-6 months. Hatching is reported to take place at the end of the year and according

to Summer and Colvin (1989) it is keyed to the new moon. Hatching is protracted and episodic and may

extend over 2 months. Hatchlings are benthonic and are large, measuring about 6-8 mm ML. Early life, the •

first 6 months, is characterized by low growth. Growth is dimorphic and accelerates with age. Sexual maturity

and sexual dichotomy appears in last half of life span. Growth may cease in both sexes during the last few

weeks of life. •

Parasites. Apicomplexa: Aggregata sp. (Hochberg, pers. obs.). Dicyemida: Dicyemennea

brevicephaloides Bogolepova-Dobrokhotova; D.filliformis Bogolepova-Dobrokhotova [=D. parva Hoffman].

For review see Hochberg (1990). i

202 |
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I Family Loliginidae d'Orbigny, 1848

I Type Genus: Loligo Schneider, 1784. Diagnosis. Mantle muscular, elongated; anteriorly projecting rostrum present at edge of dorsal

mantle. Fins posterior, extend to posterior of body; posterior end of mantle conical. Tentacle club with 4

I rows of suckers; without fixing apparatus. Anterior eye chamber covered with transparent cornea; connecting to exterior through tiny anterior pore ("lachrymal pore"). Buccal membrane with 7 lappets each with 2 rows

of tiny suckers; seminal receptacle present on membrane of female. Photophores present or absent. Right

I oviduct benthic absent. Paired nidamental glands and accessory nidamental glands present. Inshore, neretic squids; spawners

I Loligo Schneider,

1784

Type Species: LoIigo vulgaris Lamarck, 1799.

I Diagnosis. Fins posterior; eggs small to moderate size (<4 mm) contained in sausage-shaped gelatinous capsule; arm sucker ring dentition variable; hectocotylus without ventral crest; hectocotylization

consists of reduced sucker size and elongation of pedicles to form papillae on either dorsal or both dorsal

I and ventral rows; light organs absent; spermatophores with short cement body; spermatophores implanted around mouth or occasionally in mantle cavity. (Subgenus undetermined).

i Etymology. Derived from the Latin, "loligo" meaning squid.

Loligo opaleseens Berry, 1911

I Figure 6.2

Loligo stearnsii Hemphill, 1892:51 (nomen nudum). Hoyle, 1897:370.--Williamson, 1905:129.

I: --Kelsey, 1907:42. Ommastrephes tryoni Keep, 1904:271, 351 (no description; not of Gabb). --Keep, 1910:297.

i Loligo pealii opescens non LeBerry, Sueur. 1911:591-592. --Jenkins and --Berry, Carlson, 1912a:294-297, 1903:264. pls. 43(figs. 5-8), 44(figs. 2-4), 45, 46(figs.

4 and 5)

I Material Examined. California:--3 males (mature), 140-163 mm ML, western Santa Barbara

Channel, off Santa Barbara, 170 m, coll. H. Durrah,-- 1957, SBMNH 45866.--1 male (mature), 135 mm

ML, western Santa Barbara channel, off Gaviota, 155 m, coll. P. Brophy, F/V Eagle B, 19 July 1967,

, SBMNH 45981 [beak voucher].--i male (mature) + I female (mature), 127 and 126 mm ML, western

Santa Barbara Channel, 10 mi west of Santa Barbara, 120 m, coll. D. Ibara, F/V Eagle B, 22 July 1967,

SBMNH 60067.--1 male (mature) + 3 females (mature), 110 and 142-152 mm ML, off Santa Cruz Island,

I coll. CDFandG, station 23-24 SBMNH 60065. --10 males 1 female

75-A3-45, May 1975, (mature)+

(mature), 155-181 and 163 mm ML, coll. CDFandG, station 80-CFI, date unknown, SBMNH 60060.--12

males (immature and mature) + 3 females (immature), 57-181 and 55-67 mm ML, locality unknown, coll.

I CDFandG, station 76-A7-70, date unknown, SBMNH 60061.--1 clutch capsules, Pt. spawned egg Mugu,

USNMC base, off Mugu Pier, 10-12 rn, coll. G.E. and N. MacGinitie et al., 7 January 1963, SBMNH

45836.--1 clutch spawned egg capsules, Pt. Mugu, USNMC base, off Mugu Pier, 12 m, coll. G.E. and N.

I MacGinitie et al., 13 March 1963, SBMNH 45844.

I

I 203
!

Description. Body medium size, slender CH-, over 300 mm; TW to 130 g in males, to 90 g in I

females). Males larger and more robust than females (ML to 190 mm in males, to 170 mm in females).

Mantle thin, muscular; shape elongate cylindrical, longer than wide (adult lengths greater than 5 times •

width), wider medially; tapered to acute point posteriorly. Anterior dorsal mantle margin free with elongate I!

medial rostrum; ventral mantle margin deeply emarginate with prominent lateral angles on each side of

funnel. Mantle locking apparatus well developed; mantle cartilage slender, elongate ridge; funnel cartilage •

simple elongate socket with raised, reflexed margins. Fins large, about 1/2 as long as mantle; shape sagittate, |

slightly lobed anteriorly, obtusely angled anterior to middle; about 1/2 as wide as long; margins thin, entire.

Head small, compact, narrower than body; squarish; ornamented by 3 parallel, longitudinal folds of •

integument, correspond to cartilaginous ribs of rostrum. Eyes large, prominent; do not protrude. Funnel II

large, broad, short; funnel valve large, terminal. Funnel organ V-shaped with oval lateral pads. Buccal

membrane with 7 lappets, each with 2 distinct rows of minute suckers, 7-9 suckers per row, lateral ventral •

lappets with 10-12 suckers per row in females; sucker rings with 5-6 irregular, squarish teeth; inner buccal l

membrane thickened with rugose cushion surrounding beaks. Seminal receptacle present in region of buccal

membrane of females.

Gladius long, thin, ends posteriorly in blunt point; vanes well demarcated from rachis, broadly

lanceolate, widest about 1/4distance from posterior tip; free rachis moderately short, slender, ends anteriorly

in acute point; rachis with marginal fusiform thickenings. Gladius vanes wider in females than males.

Arms slender, short; shorter in males than females; lengths unequal, arm pair 1considerably shorter;

formula 3=2.4.1. Web membrane rudimentary between arms pairs 1-3, absent between ventral arms; web

extends as prominent keel along aboral margins of dorsal arms; oral margins of arms 2 bluntly carinate, D

arms 3 obscurely so; prominent flesh keel along ahoral margins of arms 2 and 3, keel extends to arm tips;

ventral arms with broad, prominent web along aboral margin ensheating base of tentacle; similar but less

well-developed keel extends along oral surface of ventral arms. Membranous swimming web present along In

oral, sucker bearing surface of all arms; strengthened by numerous, slender transverse trabeculae alternating

with pedicels. Arm suckers small, kettle-shaped; biserial, alternately arranged on short conical pedicels;

margins of cupules hood-like; sucker rings with 9-12 bluntly rounded, truncate teeth on upper margin;

papillary area wide and very prominent.

Hectocotylized arm - distal 30% of left ventral arm modified in males (HeLl 29-40); left ventral

arm stouter and broader than right ventral arm; proximally about 19-20 pairs of normal suckers; at about _1

row 20, suckers in both rows progressively reduced in size, their pedicels tall, glandular with triangular II

bases; suckers of dorsal row more strongly affected; pedicels and suckers decrease in size distally; at about

rows 30-40, suckers of ventral row and pedicels resume their normal appearance; in area where ventral D

suckers become normal, dorsal suckers become minute and on very small triangular pedicels to arm tip.

Tentacles moderately long; highly contractile. Tentacle club medium size, narrow and unexpanded

to slightly lanceolate, with prominent keel and narrow swimming web. Tentacle club suckers in 4 rows; I

marginal 2 rows of suckers very small; mesial suckers much larger; sucker rings with 30-35 small, bluntly

l

conical teeth. m

Gills very long, lameUae thin; with 65-70 lamellae per outer demibranch. H

Spermatophores short, slender (SpLI 5.7-7.2- 8.3); bulk of length occupied by sperm reservoir (SpRLI

60-75 in males smaller than 100 mm ML; 75-85 in larger males); prominently armed with numerous fine •

crochettes. II

Nidamental glands large, equal in size; accessory nidamental glands of mature females distended,

bright yellow-orange in color. Eggs small (lengths 2.0-2.5 mm); 200-300 eggs embedded in gelatinous

matrix of capsules or "egg fingers"; eggfingers spindle-shaped (lengths 50-80--200 mm, widths 10-12 mm);

stalk end tapered to adhesive base. Squid migrate inshore in dense aggregations to mate and spawn; egg

capsules clustered together in large "mops". I
IIIi 205
!

Sk/n smooth, without papillae. Color in alcohol pale buff, with numerous distinct brownish I

chromatophores scattered over dorsal surface. Photophores absent in mantle cavity.

Hatchlings large (ML 2.5-2.__27-3.2ram); mantle cylindrical, length 1.5-2.0 times width; f'ms small, •

subterminal, oval in outline, wider than long. Dorsal mantle with 6 large chromatophores in mid region

(1+2+2+1 pattern), plus 11 small ones, 3 on midline and 3-4 laterally on each side of mantle; ventral mantle

with about 40 small chromatophores randomly scattered or arranged in irregular transverse rows; dorsal •

head with 6 large chromatophores in 3 pairs (2+2+2 pattern) plus 3 small ones; ventral head with 6 large

chromatophores in 2 groups of 3 posterior to eyes plus 6 small ones; arms 1 and 2 without chromatophores;

arms 3 and 4 with 2 chromatophores in single row aborally; tentacle stalks with 6-8 chromatophores in []

single row aborally; base of dorsal arms with 1 small chromatophore; base of ventral arms with 3 small I

chromatophores; funnel without chromatophores

Type Locality and Type Specimens. Pacific Ocean - Washington, Puget Sound; coll. shrimp II

fishermen,-- 1908. Holotype: male, 132 mm ML; CASIZ 017970 [SSB 101; SU 2076; CASIZ type no. []

547]. Paratype: 1 female, 146 mm ML; USNM 214388 [SSB 101]; from same lot as hototype. Paratype: 1

male, 126 mm ML; USNM 816384 [SSB 101]; from same lot as holotype. []

[] Distribution. Endemic to waters of the California Current. Range from British Columbia, Canada

(50°N) to southern tip of Baja California, Mexico (22°N). Migrate into shallow water (15-35 m) to spawn;

distribution away from spawning grounds not know. l

R

Etymology. Named for the characteristic opalescent color of the body of live animals.

Common Name. Opalescent inshore squid (see Roper et al., 1984). []

Also referred to as the market squid, common squid, opalescent squid, sea arrow, calarnary and 1

calamari (see Hochberg and Fields, 1980).

Parasites. Dicyemida: Dicyemennea nouveli. Platyhelminthes (Cestoda): Pelichnibothrium 1

speciosum, phyllobothrid type 4, unident pseudophyllidean. Nematoda: unident, philometroid. Annelida []

(Polychaeta): Capitella capitata ovincola (in gelatinous matrix of egg capsules). For review see Hochberg

(1990). I

!

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206 m i

i
!

I Order Octopoda Leach, 1818

i Key to Species of Octopoda

1A. Skin of body smooth with distinct lateral ridge; gills with 11-12 lamellae per outer demibranch;

ofenlarged hectocosuckers tylized aarmbsent................................................................................. ; arms 2-3 times mantle length; copulatory organ larBenth ge, aocbout topu20%s leioderma of length

lB. Skin papillate; arms 3-5 times mantle length; males with 1 or more enlarged suckers on all or some

I arms; eggs small; hatchlings planktonic .................................................... Octopus ...................... 2

2A. Mantle length greater than 200mm, weight typically exceeds 50kg; skin with large folds or truncate

I papillae; enlarged present on arms; copulatory organ large,

field of 6-8 suckers in males lateral

about 20% length of hectocotylized arm; gills with 12-15 lamellae per outer demibranch; eggs

medium size, capsule length 6-9mm, spawned in festoons .................................... Octopus dofleini

i 2B. Mantle length less than 200mm ...................................................................................................... 3

3A. Mantle length less than 100mm, weight typically less than 250g; funnel organ W-shaped; skin with small pointed papillae; white spots present on dorsal mantle; funnel organ W-shaped, limbs equal;

1-2 enlarged suckers present in males on all arms; copulatory organ small, about 10% length of

I hectocotylized arm; gills with 10-13 lamellae per outer demibranch; eggs small, capsule length 2.5- 4mm, spawned in festoons; hatchlings planktonic .............................................. Octopus rubescens

3B. Mantle length less than i50mm, weight to 600g; funnel organ W-shaped, limbs unequal; crop

I diverticulum absent; copulatory 15-20% length of hectocotylized arm; gills with 12-13 lamellae

organ

per demibranch; eggs large, capsule length 14-17mm, spawned singally; hatchlings benthonic .....

.......................................................................................................................... Octopus californicus

I

Family Octopodidae Orbigny, 1840

1

Subfamily Bathypolypodinae Robson, 1928

I Diagnosis. Mid-depth to deep-water octopods; suckers biserial; suckers tubular, infundibulum

reduced in diameter, rim thick and muscular; enlarged suckers may be present in males; copulatory organ

I well anal developed; posterior salivary glands not greatly reduced in size; crop diverticulum reduced or absent; flaps absent; ink sac absent; distal oviducts very long; eggs very large (capsule length up to 35 mm),

planktonic hatchlings absent; radula octopus-like to degenerate; gills small, with reduced number of lamellae.

I Bathypolypus Discussion. Grimpe, As curre 1921;ntlBenthoctopus y defmed and perce Grimpe, ived,1921; threeandgenerTeretoctopus a are placed iRobson, n this subfamily, 1929. Anamely: fourth,

monotypic genus, Grimpella Robson, 1928, has occasionally been aligned in this subfamily but the type

I needs Benthoctopus to be reexamined originally cwas ritically placedin light by Robson of the recent (1932)redein sthe cription subfamily ofG. Octopodinae. thaumastocheirby Stranks (1988).

I

I

i 207
!

Genus Benthoctopus Grimpe, 1921 I

Atlantoctopus Grimpe, 1921.

Type Species: Octopus piscatorum Verrill, 1897; by original designation (Grimpe, 1921: 299). I

n

Diagnosis. Deep-water octopods; arms short to medium length, 2.5-4 times ML; eyes small; ligula •

short, narrow, slightly to moderately excavated, never laminate; crop diverticulum present, but reduced in

w

size; radula with unicuspid or multicuspid rachidian; body entirely smooth, mantle and ocular papillae

absent; gills with 7-12 lamellae per outer demibranch, i

Etymology. Name derived from the Greek benthos meaning "depth of the sea" in reference to the

deep dwelling habits of octopuses in this group, n

i

Benthoctopus leiodenna (Berry, 1911) new combination

Figure 6.3 i

Octopus leioderma Berry, 1911:590-591. --Berry, 1912:288-289, pl. 35(fig. 1), pl. 40(figs. 4 and 5). i

Benthoctopus hokkaidensis (Berry)-- Pickford and McConnaughey manuscripts, i

Material Examined. Neotype, see below.

Description. Body small to moderate size (TL to 21_.__0 mm, TW to 148 gm); females larger than i

males. Mantle medium size (ML 50-70 mm [Nesis, to 100 ram]); short, plumb and In-m,truncately rounded,

widest posteriorly (MWI 63-89). Stylets present, non-mineralized. Head short (HWIw 86-105), broad; neck •

region slightly constricted. Eyes small, do not protrude. PalliaI aperture narrow. Funnel slender, long (FLI |

30-58), extending well past base of arms. W-shaped; inner limbs partially adnate, outer limbs 1/2 length of

inner limbs. II

Web moderately well developed (WDI 14-24); sectors unequal, formula typically B.A=C.D.E or i

C.B.D.A.E, ventral sector distinctly shallowest; web membranes along ventral sides of arms broad and well

developed.Arms stout, short (ALl 64-68); about 2.5-3.5 times ML (AM1224-374); lengths unequal, formula •

1.2.3.4, ventral pair always shortest. Suckers small (SDIn 7-8); numerous, welt separated medially and l

transversely; often partially embedded in flesh of arms; infundibulum flared, smooth; enlarged suckers

absent. Sucker counts Rl185-102, R2/88-92, R3(males)t58-61, L3(males and females)/82-87, R4t80-92. i

Hectocotylized arm - right arm 3 (HAMI 127-139); distinctly shorter than opposite arm (OAI 69- 89); I

spermatophoric groove well developed; HASC 58-61 suckers, OASC 82-87. Copulatory organ medium to

large (LLI 11-18); ligula elongate, conical, distinctly recurved, margins thick and fleshy, copulatory groove i

narrow, deep, with numerous transverse striae; calamus small (CLI 12-20), conical. l

Gills medium length (GLI 27); with 1-12 lamellae per outer demibranch.

Internal organs not described. Ink sac absent, but duct present. 1

l

Terminal organ large (TOI 35).

Mature ovarian eggs large (capsule length 14-17 mm; spawned eggs 17-18 ram). Hatchlings presumed n

benthonic. II

Skin soft, smooth, with distinct keel-like lateral mantle fold; small simple papillae on dorsal surface

of head and neck; 1 large papilla over each eye; row of 4 papillae between eyes. Color in life uniform i

pinkish tan, web and arms darker reddish purple; patch and groove system absent. Color in alcohol dorsal

mantle pale tan, gray buff or brownish red; arms and web darker; ventral mantle lighter.

I

208 i
I

I

I

I

__. ... .

I Figure 6.3. Benthoctopus leioderma:lateral view of living animal. (afterBerr, 1912a).

I Type Locality and Type Specimens. Eastern North Pacific Ocean, USA, Alaska, Shelikof Strait,

[Cape Uyak, S 10°W, 5.8 mi], 106-112 fm [194-205 m]; USBCFAlbatross, station 4293. Holotype - female

I (immature), 44 mm ML; USNM 214322 [SSB 137], no longer extant. Neotype - Female (immature), CASIZ 031369 [SSB 173, SU 2132]; preserved in alcohol in good condition.

Neotype Locality. Eastern North Pacific Ocean, USA, Gulf of Georgia, Alaska, 111-170 fm [203-

I 310 m]; USBCF Albatross, station 4194.

Distribution. Reported to occur in the Sea of Okhotsk, Bering Sea and Kurile Islands through

Alaska south to California (Monterey Bay). Known to occur in moderate depths from 90-500m, on muddy

I sand bottoms.

Etymology. Name derived from the Greek leios and derma meaning "smooth skin".

I Common Name. None. Discussion. The above diagnosis is based on Berry's original description and figures, plus

examination of two specimens identified by Voss in the NMNH (USNM) and additional comparative material

I in the collections of the YPM and SBMNH. The holotype is no longer extant and Berry did not designate any paratypes. Two juvenile specimens from the same lot as the holotype were recorded by Berry in his card

file. One of these, a female (USNM 214664) was not found in July of 1985. An additional female specimen

I resi description des in the collections of the CASIZ. Although mentioned but not measured by Berry in his original it is herein designated as the neotype for Octopus leioderma.

None of the specimens available to Berry were dissected for his original description, hence the

I presence or absence of an ink sac was not determined. Robson (1932: ) felt that, based on general

appearance

and body proportions, Octopus leioderma was closely related to Benthoctopus hokkaidensis. The neotype

and comparative material which can be referred to this species were found to lack an ink sac and hence the

I species herein is transferred to the genus Benthoctopus.

Biology. Little is known of the biology of this species.

i Oregon PandaraVancouver sites. Two undescribed dicyemid species have been recorded from specimens collected off Island, Canada (Hochberg and McConnaughey, unpubl.).
!

Benthoctopus robustus Voss and Pearcy, 1990 [

Figure 6.4

Benthoctopus robustus Voss and Pearcy, 1990:67-69, figs. 9a-h, 10a-e.

Polypus januarii not Hoyle. -- Hoyle, 1904:18. i

Material Examined. Canada:--Paratype 1 male (mature), 114 mm ML; British Columbia, Queen

Charlotte Island, 140 nautical mi offTasu Sound, 52°27.4'N, 135° 34.4'W, 3660 m; coil. E. Houde, sablefish

trap, 16 October 1978, USNM 730895. 1

U

Oregon:--Holotype I male (mature), 137 mm ML; off Newport, eastern portion of Cascadia Abyssal

Plain, 44°38.5'N, 126°03.8'W, 2800 m; coll. R/VAcona, station NAD22, I June 1963, USNM 729994.--i I

male (immature), 85 nun ML; SW of Columbia River mouth, 45°44'N, 124°54'W, 1189 m; coll. W. Pereyra i

and Alton, BCF-AEC Project, M/V Commando, 72 ft shrimp trawl, 28 August 1963, YPM 13218.

Mexico:--I female (gravid), 125 mm ML; off Baja California del Norte, 30°57.9'N, 119°08.0'W, •

3840 m; coll. C. Hubbs and party, R/V Melville, station MV-69-VI-5A, free vehicle setline and trap, 16-17 1

December 1969, SBMNH 42224.

Description. Animal large. Mantle compact, robust, muscular (ML to 142 mm), rounded, longer U

than wide (MWI 77-80). Head small, narrow (HWI 48-51); distinct neck region absent. Eyes small, do not

protrude. Pallial aperture narrow. Funnel large, long; free for half its length; aperture small. Funnel organ

very large; W-shaped; limbs wide, lateral limbs equal to or slightly longer than median limbs, median limbs i

round.

Web heavy, deep (WD135); sectors subequal, formula typically D.B.C.A.E or C.B .D.A.E; membrane

extends along ventral edge of arms about 2/3's their length. Arms moderately long (ALI 57-68); about 5 i

times ML; stout at base (AWI 12-16), tapered rapidly to stout, attenuated tips; lengths subequal, formula

typically 4.1.2.3 or 3.2.1.4. Suckers small (SDIn 5.1-5.7); well separated, erect on stout bases; enlarged

suckers absent. Sucker counts - males: arms 1 with 38-40 suckers. Hectocotylized arm - fight arm 3 (HAMI I

); shorter than opposite arm (OAI 80- 85); stouter than other arms; spermatophore groove formed by thick

in-rolled web. Copulatory organ large (LLI I2-13); ligula elongate, conical, margins thick and fleshy,

copulatory groove deep, with 14-16 transverse folds; calamus large, long (CLI 38-45), slender, sharply i

pointed. 11

Beaks - rostrum of upper beak very small, sharp and curved; rostrum of lower beak forms 90 angle 1

to jaw angle. Radula - rachidian simple, narrow, with single small cusp on thin cutting edge; 1st laterals i

with tall sharp ectocone; 2nd laterals with straight inner edge; 1st marginals slender, curved, sabre-like; !

marginal plates present. Digestive tract- esophagus slender; crop with small, distinct anterior diverticulum;

stomach large, muscular; caecum small; intestine inflated distally; rectum about 113length of intestine; anal I

flaps absent; digestive gland nearly spherical. Ink sac absent. R

Gills large; with 11 lamellae per outer demibranch. 1

Male genitalia (mature) - spermatophoric gland I wide, thin wailed; gland II about 2/3 length of i

gland I, appendix present; spermatophore storage sac long, triangular, filled with relatively few, large

spermatophores; terminal organ very large (TOLI 58), with long diverticulum. Spermatophores long; horn •

(oral cap) with 3 tight turns. l

Female genitalia (mature) - not described.

Skin entirely smooth; lateral mantle fold absent; papillae absent on mantle, head and arms. Color i

(in life) pale pinkish. Color (in alcohol) pale tan dorsally and on aboral surface of arms; light reddish- brown

on ventral side of head, around and on funnel, around eyes and on web; web margins darkish purple. Some

specimens appear to be reverse countershaded. I

210 I
I Figure 6.4. Benthoctopus robusms: A, lateral view of holotype (USNM 729994), male 137 mm ML; B, ligula;

C, digestive tract of paratype (USNM 730895), male, 49 mm ML; D, crop of holotype; E, crop of

I parat Pearcy, ype;1990). F, funnel organ of holotype; G, H, upper and lower beaks of holotype. (after Voss and

I

I.

i 211
!

Type Locality and Type Specimens. OREGON, off Newport, eastern portion of Cascadia Abyssal i

Plain, 44°38.5'N, 126°03.8'W, 2800 m. Holotype - male (mature), 137 mm ML; USNM 72994; preserved in

isopropyl alcohol, in good condition. Paratype - male (mature), 114 mm ML; USNM 730895. •

Distribution. Known range from Oregon to off Baja California, Mexico. Precise northern and |

southern limits unknown. Known depth range from 1,200-3,850 m.

Etymology. Specific epithet derived from Latin robustus meaning "hard or strong" in reference to i

the species' stout, muscular body.

Common Name. None.

m/

Biology. Little is known about the biology of this rare, deep sea octopus, i

Parasites. A undescribed species of dicyemid parasite has been discovered in the kidneys of an

animal off Mexico (Symbiotype SBMNH 42224; Hochberg, unpubl.), I

Subfamily Graneledoninae Voss 1988 i

It

Diagnosis. Deep-water octopodids; suckers uniserial, small; enlarged suckers absent; ink sac absent;

funnel organ V- or VV-shaped; copulatory organ small to medium size (LLI <8), calamus large (CLI >50); i

radula homodont, reduced or degenerate; crop simple without diverticulum; posterior salivary glands small II

to vestigial; spermatophores large and few in number; gills small, with reduced number of lamellae.

Discussion. Robson (1932:51-56) discussed the Etedoninae (i.e., octopodids with a single row of i

suckers) and considered the subfamily to be polyphyletic. With this in mind Voss (1988a: 270) erected the

new subfamily, Graneledortinae, to contain three genera, namely: Bentheledone Robson, 1932; GraneIedone

Joubin, 1918 and Thaumeledone Robson, 1930. According to Voss all three genera share the following key i

characters: 1) lack of an ink sac; 2) lack of a crop diverticulum; and 3) degenerate radula.

Genus Graneledone Joubin, 1918 H

Type Species: Eledone verrucosa VerriU, 1881; by original designation (Joubin, 1918b: 39).

! Diagnosis. Skin of dorsal mantle, head, eyes and bases of arms 1 and 2 covered with permanent

rosette-like clusters of rugose cartilaginous tubercles; gills with 6-8 larneUae per outer demibranch; funnel i

organ large, VV-shaped; posterior salivary glands small; 1-3 large multifid papillae over each eye; radula i

with very large cusps on second laterals and marginals. i

Etymology. Derived from the Latin granum meaning "small kernal or grain" in reference to the I

granule-like, cartilaginous tubercles characteristically present on the dorsum of species in this genus.

Discussion. Over the years several species have been placed in the genus Graneledone which

presently are considered to belong in other genera, namely: G. rotunda Hoyle, 1885 [= Bentheledone] and 8

G. poIymorpha Robson, 1930 [=PareIedone]. In addition, several unidentified specimens have been indicated I!

to be present in various parts of the world, namely: Gulf of Panam_i in 1865- 2500 m (Hoyle, 1904; Nesis,

1982, 1987; Voss, 1988b); in 1866 m off Costa Rica (Hochberg, unpubl.) and in I 100 m off Perti (Hochberg, •

1992, unpubl.). l

!

!

212 I
!

I Graneledone boreopacifica Nesis, 1982

Figure 6.5

i Graneledone boreopacifica Nesis, 1982:322, textfigs. 85k, 1.-- Nesis, t985:48; -- Avdeev, 1986:49; --

Nesis, 1987:322, textfigs. 85J, K [translation of original description];-- Nesis, 1989a:27-28. --

I Nesis, 1989b:1001, textfig. 2; -- Hochberg, 1990:193-196.

Graneledone pacifica Voss and Pearcy, 1990:85-92, figs. 18a-g, 19a-h, 20a-g, tables 18, 19.

i Graneledone Graneledone sp. --A. Avdeev, -- Voss, 1982:108, 1988b:303,114; fig. --8. Voss, 1988a: fig. 2k.

Moschites sp. -- Berry, 1917: 4.

I verrucosa not -- Hoyle,

Moschites Verrill. 1904:21.

Graneledone challenged not Berry-- Robson, 1932:311-313 (in part), textfig. 71.

I JapetelIa heathi not Berry. -- Hanna, 1952:357, pl. 13(fig. 2).

Material Examined. Oregon: Holotypeml male (mature), 85 mm ML; Cascadia Abyssal Plain

i near USNMthe slope, 44°52.0'N, 125°32.8'W, 2706 m; coll. R/V Yaquina, station Cr. 6907C haul 95, 16 July 1969, 730716.-- 6 juveniles, 16-42 mm ML; SW of Columbia River mouth, 45°45'N, 125°09'W, 1646 m;

coll. W. Pereyra and Alton, M/V Commando, 70 ft semi-balloon shrimp trawl, 29 May t964, YPM 13249.--

i 1 male (immature), 60 mm ML; SW of Columbia River mouth, 45055.2'N, 125°08.8'W, 1463 m; coll. W.

I Pereyra and Alton, M/V Commando, 70ft semi-balloon shrimp trawl, 29 May 1964, YPM 13250. -- 1 male

(mature), 135 mm ML; SW of Columbia River mouth, 46°03.5'N, 125005.7'W, 1463 m; coll. W. Pereyra

i and Alton, California:-- M/V Commando 1female , 70(subadult), ft semi-balloon 100 mmshrimp ML; trawl, Humboldt 30 May Co., 1964, north ofYPMCape13256. Mendocino, 41°4 I'N,

125°19'W, 1300 m; coll. California Dept. Fish and Game, 26 May I969, SBMNH 42223. -- 2 males

I (immature), Farallones Oce60,anic 64 mmResearch ML; SanExpeditio Francisco n, 27Co., Julyoff1991Farallon SBMNH. Islands, -- 2980 1 femalem; coll. (mature), J. Nybakken 145 mmandML;party, San

Luis Obispo Co., off Avila near Santa Lucia Banks, 35°06.2'N, 121°38.8'W, 688-698 fm [1258-1277 m];

i coll. SBMNHS. Kato 64541. and party, R/V D.S. Jordan, tow #6, 93 ft modified Eastern otter trawl, 7 September 1976, -- 1 female (juvenile), 33 mm ML; Santa Barbara Co., south of San Miguel Island, 1036

m; SBMNH 63332.- 1 male (mature), 125 mm ML; south of Cortez Bank, 32°15'N, 119°01'W, 1050 m;

i coll. Monterey F/V Calafia Bay, 36041 , 5 October 1978, SBMNH 63333. -- 1 male (mature), 95 mm ML; Monterey Co., off ' N, 122°19'W, 1336-1347 m; coll. E. Anderson and party, USNS De Steigner, 7.5 ft

McDuck beam trawl, 19 November 1975, CASIZ 031500.- 1 male (mature), 95 mm ML; Monterey Co.,

i off Soberanes Pt., 36°28'N, 122°17%V, 1384-1409 m; coll. E. Anderson and party, USNS De Steigner, 7.5 ft McDuck beam trawl, 21 November 1975, CASIZ 031474. -- 2 females (mature), 130 and 130 mm ML; off

Bodega, 4-5 mi N of Bodega Canyon, 1197-1244 m; coll. Capt. Ed Bishop, F/V Eagle, 27 December 1976,

CASIZ 003318. -- 1 female (immature), 80 mm ML; N. Farallon Island, 10 mi SE of Farallones, SW x Sll

I 4, 1280-1463 m; coll. FN N.B. Scofield, station 155 [NBS 50B- 88], beam trawl, 12 November 1950,

CASIZ 035044.

i

females);Description. moderately wide Body(MWI mediummalesto large. 87-92.9-100, Mantle females firm, muscular; 81-92.1 -short 115); ((ML widest80-145, medially.mature Headmales narrower and

to slightly wider than mantle (HWI males 54.5-72.7-83, females 60-72.0-115); not distinctly set off from

i mantle. Eyes large, protrude very slightly; apertures small. Funnel large, stout (FLI); free about 1/4 of its length (FFLI); inner edge forms strong flap which inserts in deep pouch in inner mantle wall to form

effective "locking apparatus". Funnel organ very large (fills almost entire length of funnel in immature

i animals); pads thick, orangish; VV-shape, limb widths and lengths variable.

i 213
!

Web moderately deep (WDI males 17.4-30.9, females 22.9-31.3); sectors subequal, formula I

C.D.B.A.E or B.C.D.A.E.Arms moderately long (ALI males 72-78.7-84, females 74-75.6-77); 2.3-3.4 times

ML (MAI males 25-27.6-32, females 25-29.1-31); muscular, stout (AWI males 19-21.6-24 [Nesis 16-18.1- •

20], females 18-20.2-24), round in cross-section, taper to long slender tips; lengths subequal, formula typically l

1.2.3.4, less frequently 2.1.3.4. Suckers small (SDIn males 4.8-7.4 [Nesis 5.6-6.3], females 4.4-7.7 [Nesis

5.2-6.7]), largest suckers in region of web insertion; well separated; urn-shaped, rim inflated and crenulated; am

embedded in flesh of arms; enlarged suckers absent. Sucker counts - male: HASC 40-48, OASC 60-94; |

female: arm R3 or L3/88-108.

Hectocotylized arm - right arm 3; shorter and more robust than opposite arm (OAI 71-82.4-86); I

spermatophore guide distinct (on margin of web between arms R3 and 4); spermatophore groove well II

developed, web broad, thickened at margin, white (devoid of chromatophores). Copulatory organ small

(LLI 4.5-5.6-6.5); ligula short, broad, spade- or heart-shaped, copulatory groove deep with numerous low II

transverse laminae, often with low median, longitudinal ridge; calamus large (CLI 59-62.8-83 [Nesis 40- II

70]), narrow, sharply pointed.

Gills large, stout; with 7-8 lamellae per outer demibranch.

Buccal mass large; anterior salivary glands small; posterior salivary glands small, narrowly elliptical. U

Beaks - upper beak with strong deep jaw angle; lower beak with 90°jaw angle, distinct groove along lower

edge of insertion plate. Radula - rachidian varies from multicuspid with B8 seriation to simple (homodont), m

almost degenerate; first lateral very small with small cusp; second lateral with large, very broad cusp;

marginal with large, broad cusp. Digestive tract - esophagus slender; crop simple, inflated, slightly wider

than esophagus, without anterior diverticulum, inner walls strongly plicate; stomach slightly larger than 1_

caecum, bipartite, anterior half muscular, thick- walled, posterior half thin-walled; caecum small; intestine

short, stout, with sharp bend in proximal quarter, without bulbus; anal flaps absent; digestive gland large,

rounded; paired digestive gland ducts large, thin-walled. Ink sac absent, n

Male genitalia (mature) - testis not figured; spermatophoric gland I long, stout, about 2 times longer

than gland IT;spermatophoric gland 1Twithout appendix; spermatopbore storage sac very long, stout anteriorly,

tapered to elongate point posteriorly, contains few large spermatophores; terminal organ large, short and n

stout; diverticulum large, stout, strongly reflexed. Spermatophores long (SpLI 145-157.0-169), stout (SpWI RI

4- 5); sperm reservoir large (SpRI 41), swollen in region of sperm mass, flesh colored; cement gland dark

purplish-red to maroon; oral cap (= horn) with 3-4 loose coils just prior to end. n

lib

Female genitalia (mature) - ovary moderately large; proximal oviducts very short, stout; oviducal

glands large, round and flattened, distal half appears pleated, dark blue-gray; distal oviducts short, very

swollen; genital pore small, subterminal. Eggs large (mature ovarian capsule length 16 mm), widest i

posteriorly, flesh colored with about 10-12 striations (follicular folds); stalk short, white. m

Skin soft, loose; dorsal mantle, head and bases of arms 1 and 2 densely covered with small, round n

(diameter 1-4 nun) clusters of cartilaginous tubercles, each rosette-like cluster typically consists of 2-6/7-11 I!

small blunt tubercles surrounding a larger central one; raised above body surface on low fleshy pad (in life

tubercles capable of being erected as tall rugose papillae); skin between tubercles smooth; ventral mantle

and ventral arms smooth without tubercles; 1-2 large papillae above each eye, each covered with small

tubercles; some specimens with distinct demarcation line on lateral mantle separating light dorsal mantle

from dark ventral mantle (often appears as lateral mantle fold). Color (in alcohol) variable, ground color HI

pinkish-gray to reddish-brown or reddish-purple; web and oral surface of arms slightly darker; some specimens i

are distinctly reverse countershaded with the dorsal mantle, head and arms lighter than the dark red ventral

surfaces; eyes dark colored; tubercles typically stand out as pale round spots; funnel dark, distal tip (around land

aperture) with light ring; lip of pallial aperture light or white; sucker bases dark, rims distinctly white i

(devoid of chromatophores).

I

!

214 n
!

!

I

!

Figure 6.5. Graneledoneboreopacifica: lateral view of holotype, USNM 730716,male, 85 mmML. (afterVoss

I and Pearcy, 1990).

I Type Locality and Type Specimens. North Pacific Ocean, 50°04'N, 151°35'W, 1350 m. Holotype

--male (mature), 110 mm IV[L;ZIN, unregistered. Paratypes--1 female (immature), 32 mm ML; IOAS,

I unregistered.-- 2 males (immature), 58 and 65 mm ML; IOAS, unregistered. Distribution. A boreal, lower-bathyal species recorded in the western Pacific Ocean offNE Honshu

Island, Japan, in the Sea of Okhotsk and in the Eastern Pacific Ocean from Washington to southern California,

I USA. Ranging in depths from 1,000-3,000 m. Etymology. Named in recognition of the boreal distribution of the species in the North Pacific

Ocean.

I Common Name. None.

Discussion. Voss and Pearcy (1990) named and described in detail Graneledone pacifica from the

I E1982. asternTheNorth holotype Pacific. ofGTheir species is considered herein to be a junior synonym of G. boreopacifica Nesis, . pacifica is a mature male, 85 mm ML; USNM 730716, preserved in 50% isopropyl

alcohol, in good condition. Additional paratypes of G. pacifica are in the NMNH (USNM); CAS (CASIZ

i 0Abyssal 61433, 0Plain 61434); nearRSMS the slope, (UMML) 44°52'N, and S125BMNH. °32.8'W, The2,706 type locality m. Vossof and G. pacPearcy ifica i

(1990) s off Oregon, reportedCasca thatdiaG.

pacifica has been captured on the continental slope, slope base and eastern boundary of the Cascadia Abyssal

i Plain. It was not found on the Western Cascadia or Tufts plains and, hence, appears to be a species that lives

I[ near the continent wherever it occurs.

Based on the examination of additional material easily recognized as G. boreopacifica [= G. pacifica]

I inNorth the collections of SBMNH, CASIZ and YPM, the species is confirmed to be distributed in the Eastern Pacific as far south as southern California.

Hoyle (1904: 21) reported the presence of an animal matching the description of GraneIedone

I other verrucosa hand,fromindicated 1865 mtheoffpresence Cape Malfi of iannewthe Gulf species of Panamfi. of Graneledone Nesis (1982, in the1987Gulf ) andof Voss Panarn(1fi988b),

. Additional on the

specimens of an unidentified species from Costa Rica (adult, spawned egg mass and hatchlings) and Perti

I (specimen spawned fromegg mass) Panam_i aredoesin the not coappear llections to beofexttheantSBMNH and hence(Hochberg, can not be compared unpubl.). with Unfortunately, the above material. Hoyle's

If these specimens prove to be G. boreopacific the distribution will be extended south at least to Panan_.

I

I 215
!

Hoyle (1886:104) earlier reported the presence of Graneledone ve rrucosa in 1152 m off the Kermadec i

Islands. Berry (1916:49-50) proposed a new name chaUengeri for the specimen off the Kermadecs based

primarily on the geographic separation from the type locality of the true G. verrucosa which is in the 1

Western North Atlantic (for a discussion see Voss, 1976:457). Robson (1932:311-313) confused the situation |

when he later treated both Hoyle's Kermadec and Panamfi specimens under Berry's name. The specimen

from the Kermadecs is considered to represent a species distinct from G. boreopacifica. Lu and Mangold I

(1978) recently collected large numbers of an unidentified species of Graneledone from the Kerguelen and I

Heard Islands in the Indian Ocean. Whether their specimens relate to G. challengeri or to G. antarctica has

not been determined. II

Parasites. Avdeev (1982) described two species of host specific harpacticoid copepods from the R

gills of specimens collected in the Western North Pacific: Cholydiella incisa and Brescianiana rotundata.

Copepods have not been reported from Graneledone specimens in the Eastern Pacific. For review see •

Hochberg (1990). 1

Subfamily Octopodinae I

Genus Octopus Cuvier, 1797 i

Diagnosis. Adults - small to large shallow water octopodines; mantle muscular, globose to rounded

ovoid; skin with distinct patch and groove system which appears as dark trellis or reticulated pattern; dorsal

mantle white spots present; frontal white spot complex present; fixed pattern of 4 long primary papillae in i

diamond pattern on mid-dorsal mantle; furmel organ W-shaped; water pores absent; stylets present, not

mineralized; eyes not protruding; arms muscular, medium length (3-5 times ML), lateral arms longest,

formula typically 2.3.4.1 or 3.2.4.1; suckers large, infundibulum large and flared; enlarged suckers present i

in males and females, modified non-functional suckers at tips of arms of males absent; right arm 3

hectocotylized; copulatory organ with distinct ligula and calamus; spermatophores unarmed; oviducal glands

distinctly bipartite, spermatheca present, braiding chambers present; fertilization occurs in oviducal gland; •

eggs always laid in festoons. il

Hatchlings - planktonic or benthonic; Kflliker bristles present. In planktonic species mantle bluntly

ovoid; arms with few to many suckers, subequal throughout paralarval development. B

m

Type Species: Octopus vulgaris Cuvier, 1797; by absolute tautonomy (see ICZN Opinion 233).

Etymology. Name derived from the Greek okto andpous meaning "eight footed" in reference to the •

animal's eight arms. g

Octopus dofleini Wiilker, 1910 l

I

Figure 6.6

Octopus dofleini Wiilker, 1910:7, pl. 2(figs. 1-2), pl. 3(fig. 10). 1

In addition, it has been placed in the genus Paroctopus by some workers.

1

Material Examined. California:--I female, 253 mm ML; off San Miguel Island, 3 mi west of i

Richardson Rock, Elbow Bank, 34°08'N, 120°34'W, -25 fm [45 m]; coll. E. Wike and Capt. R. Hart, F/V

Condor, hook and line, 3 February 1993; SBMNH 143068 [photographs].--1 female, 160 mm ML; off San •

Miguel Island, 3 mi west of Richardson Rock, Elbow Bank, 34008'N, 120°34'W, 300 fl [91 m]; coll. Capt. l

M. McCrea, F/V Sea Hawk, hook and line, tl January 1996 [released 3 February 1996]; SBMNH 143069

IDNA voucher].--1 female, 190 mm ML; off San Miguel Island, 3 mi west of Richardson Rock, Elbow i

216 I
!

I Bank, 34°08'N, 120_34'W, 200-220 ft [61-67 m]; coll. Capt. R. Hart, F/V Condor, hook and line, 2February

1996 [released 3February 1996]; SBMNH 143070 [DNA voucher].--1 male, 380 mm ML; due S of Santa

Barbara Harbor, 60 fm [110 m]; coll. Capt. B. Bramly, F/V C, commercial prawn trawl, 6 April 1996

I [released 1 May 1996].

Washington: --1 female, 200 mm ML; Clallam Co., Neah Bay, mile 6.2, under rock to left of bay,

I intertidal death 8 July[0 m]; 1993]; coll.SBMNH R. Anderson, 143143by[FD-246; hand w/quinaldine, DNA voucher]. 25 April --1 1993 female,[maintained 255 mm ML; in aquarium Clallam until Co.,

Discovery Bay, S of Mill Point, in ballast pile adjacent to wreck of S/V Warhawk, 30 ft [9 m]; coll. R.

I Anderson, 1994]; SBMNH by hand143144 wt quinaldine, 28 October 1994 [maintained in aquarium until death 23 November [FD-255; DNA voucher]. --1 female, 350 mm ML; King Co., off Seattle, MeKwa

Mooks Park, Jacobsen Reef, 60 ft [18 m]; coll. J. Christensen, by hand wlquinaldine, 30 October 1994

i [maintained Britishin aquarium Colombia,until Canada:--I death 8 November male, 65 mm1994]; ML;SBMNH Dundas 1431 Island, 45 [MD-256] small islet off Armiston Point,

54°38'N, 130°55.3'W, intertidal; coll. P. Lambert and P. Kerfoot, 21 June i974; BCPM 974-233-26.--1

I female, Peden, 1270 September mm ML; Queen 1973;CBCPM harlotte 973-219-6.--1 Sound, 51°22.0'N, male,12864°44.4mmN_,ML;122-124 W Barkley fm [223-227 Sound, m]; 48°44.4'N, coll. A.

126°30.0'W, 461 m; coll. F.R. Bernard (Biological Station, Nanaimo), cruise 63-185, station 3, line 2, 8

I September 123°32Nd, depth 1964;unknown; BCPM 977-336.-- coll. I.E. Cornwall, 1 male, 2225 May mm 1924; ML; Vancouver BCPM 982-60. Island, --1 William male + 1Head, fmale,48_20'N, 55 and

50 mm ML; Queen Charlotte Sound, 5I°10'N, 129°18.8'W, 142-152 fm [260-278 m]; coll. A. Peden, 7

I September Gabe, Vancouver 1973; Public BCPMAquarium,-- 973-200-4.--1October female, 1973; 225SBMNH mm ML;143071 off Vancouver, .--1 male, 445depthmmunknown; ML; off Victoria, coll. S.

Sealand, depth unknown; coll. S. Gabe, Vancouver Public Aquarium, 23 February 1974; SBMNH 45786

I Mantle Description. Adults - Animals large (TL 945-110____._55-1620 ram); body large (ML I58-19___55-330 mm). rounded-ovate, broad (MW167-87-102). Head narrow (HWIw 33-41-62); neck wider than head;

eyes medium size, not protruding. Funnel long (FL135-40). Funnel organ W-shaped, limbs broad, outer

I limbs typically about half as tong as inner limbs (FO142-64). Web moderately deep (WD117-22-28); sectors subequal, formula typically B=C=D.A.E, ventral

sector always shallowest, about half as deep as deepest sector. Arms moderately long (AL170-81-84); 3-5

I times ML (AMI); subequal, formula typically 2=1.3.4. Suckers large (SDIn males 13-17-19, females 12- 14), larger in males than females; slightly elevated, infundibulum flared with distinct radial cushions;

conspicuously enlarged suckers absent.

I arm hectocotylized ); markedly opposite arm (OA180-109). Right 3 (HAMI not shorter than

Copulatory organ very long (LL120-2_4);ligula slender, pointed, copulatory groove tightly closed, ornamented

with regularly arranged transverse rows of 6-8 papillae per row; calamus short (CLI 5-8_).

i Gills long; with 12-1__33-15lamellae per outer demibranch.

Radula - rachidian tooth with asymmetrical B4 sedation of rachidian; marginal plates fiat, without

I cusp; other Genitalia teeth not described. of mature male - testis round; vas deferens encased in elongate tubular membrane (not

spherical); spermatophoric gland long, narrow, spirally coiled and reflexed back on itself; spermatophoric

I gland contains11lovery ng, tubular, distal end blind with reflexed tip; spermatophore storage sac very long and narrow, few spermatophores; apex of terminal organ (penis) short; diverticulum very long.

Spermatophores very long (SpL1342, 346); horn with 10-15 spiral turns.

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Figure 6.6. Octopus dofleini: view of living specimen.(from Morris,Abbott, andHaderlie, 1980). I

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Genitalia of mature female - ovary large, round, distended; proximal oviducts short, narrow; oviducal

gland large (OGDI 23-24), bean-shaped, distinctly bipartite, proximal portion small, appears "pleated" m

(indicates radial chambers present), distal portion much larger, smooth and uniformly darker; proximal and •

distal oviducts enter and leave gland side by side at b_ilium;initial section of distal oviduct greatly inflated

ill

and wrapping around gland (accessory seminal receptacle). Eggs small (spawned capsule length 5.9-6.4

mm), stalks long (stalk length 13.8-17 mm); laid in festoons, stalks braided together. Hatchlings planktonic. _l

u

Color in formalin, dark reddish brown dorsally, often mottled with black streaks or reticulations;

paler below without conspicuous dark reticulation; frontal white spot complex present; dorsal mantle white Im

spots present; patch and groove system present, patches large, irregular-shaped oval to narrowly elongate. II

Skin in life loose, often smooth or with parallel longitudinal ridges or folds; in preservation appearing

wrinkled, generally rugose or papillated dorsally; oral surface of web finely granulated; 4 primary papillae III

in diamond pattern on dorsal mantle, appear stellate at base; 2 large flattened primary papillae above and |

just behind each eye ("horn or ear-like"); single secondary papillae near front of each eye.

Hatchlings - Recent hatchlings large (ML 3-3.5 mm); arms subequal with 10-14 suckers; arms with •

8-9 chromatophores in 1 row; funnel with 2+2+4+8 chromatophores; dorsal mantle midregion (over digestive II

gland) barren, anterior margin with band of 4-6 chromatophores, posterior region and sides with numerous

chromatophores; ventral mantle barren, posterior region with 10+ chromatophores visible; dorsal head with •

4+4 chromatophores, eye chromatophore number unknown; ventral head with 2 chromatophores; visceral II

chromatophore number unknown; silver iridophores around eyes.

Munich.Type Locality and Type Specimens. Japan, Hokkaido Island. Holotype: University Museum, Imm

Distribution. San Diego, California to Japan.A boreal species restricted to the North Pacific Rim.

Intertidal to 1500m, typically shallow subtidal to 100m. I

218 I
I

I Common Name. Giant North Pacific Octopus.

Distribution. Eastern North Pacific from San Diego, California to British Columbia, Canada. Depth

I range from 0-1500 m, typically shallow subtidal to 100 m. Common Name. Giant North Pacific octopus.

Discussion. The above diagnosis is based on the original description, tables, and figures. Additional

I have been examined unpub.) and color of live animals have

specimens (Hochberg, photographs numerous

been studied.

i Pickford's (1964) subspecific description of Octopus dolfleini martini for Canadian, Washington and California populations of the Giant North Pacific Octopus is not accepted. Additional critical

morphometric, anatomical and behavioral work needs to be done on mature animals before they can be

i adequately separated from populations to the north and west.

Octopus rubescens Berry, 1953

I Figure 6.7

Octopus punctatus Gabb, 1862 (in part). -- Wheeler, 1899:169-176.

I Polypus sp. (young/juv.).- Berry, 1911:303-304; Berry, 1912:289.

PoIypus hongkongensis not Hoyle. -- Berry, 1911:302-303 (in part); Berry, 1912:280, 282-283, 333 (in

I Potypus part), textfig. 2, pl. 39(fig. 3). apoltyon Berry. --Berry, 1913:72 (in part), text fig. 1; Fisher, 1923:147-149, pl. 5; Fisher, 1925:411-

414, pl. 27(figs. 1-6).

I Paroctopus apoUyon (Berry). -- Robson, 1929:202-204 ( in part), text fig. 82.

Octopus apollyon (Berry). -- McConnaughey, 1949:12; Winkler and Ashley, 1954:24-26 (in part), text

figs. 18-19.

I Octopus rubescens Berry, 1953. -- Halstead, 1965:731,739-740; Packard and Hochberg, 1977:208-219,

figs. 28, 32-33; Hochberg, 1980:204; Hochberg (1987); Hochberg and Fields, 1980:435-436, pl.

i 135(fig. 17.6).

Material Examined. Over 50 lots from California (SBMNH).

i ovate; Diagnosis. Body small (TL 115-17..__Q0-255 ram; adult ML 35-100 ram); mantle rounded to rounded- slightly longer than wide (MWI 70-83-98), widest posterior to mid mantle. Stylets present, nonmineralized. Head short, distinctly narrower than mantle (HWIw 64-76-89); separated from mantle by

i slightly constricted neck region; eyes large and prominent, not protruding. Pallial aperture wide (PAI 60- 66-83). Funnel medium length (FLI 4_7_),extends about 1/2 distance to web margin, broad at base tapering

rapidly to slender constricted apex. Funnel organ W-shaped, limbs wide, narrowly separated, subequal.

I D.C.B.E.A; Webweb thin,membrane transparent,extends moderately about 1deep /2 way(WDI up ventral 19-28);edge sectorsf each nearlyarm.suArms bequal,slender, formulamoderately typically

long (ALI 72-75-85); 3.5-4.5 times ML (AMI 318-363-464); rapidly tapering to slender tips; lateral arms

I slightly spaced and longest, distinctly formula elevated; typicallyinfundibulum 2.3.4.1, dorsal cup-like, pair shortest. slightly flared Suckerswithmoderate radial cushions; size (SDIn1-28-11-13); conspicuously widely

enlarged suckers present on all but ventral arms of males (SDIe 13-1__2),less conspicuously enlarged on

I females, ventral sucker of 6th pair at web margin typically deeper and more robust but not much wider than normal suckers; sucker counts Ll1164.

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Hectocotylized arm right third arm 0-IAM1258-289-329); distinctly shorter than opposite arm (OAI I

72-94); spermatophore groove closely adnate, web membrane narrow; HASC 95. Copulatory organ

moderately long (LLI 8-11); ligula well developed, elongate-conic, margins abruptly elevated, wide and ill

fleshy, copulatory groove deep with 15-24 transverse ridges and grooves; calamus small (CLI 1_9). |

Gills with 11-13 lamellae per outer demibranch; long (GLI 50). Internal anatomy not completely

described. Ink sac large, conspicuous, l_

Genitalia of mature male, testis oval; vas deferens long, narrow, convoluted bound in membrane;

spermatophoric gland I narrow; spermatophoric gland 11with distinct bend at bluntly rounded distal blind

end; spermatophore storage sac narrow, pointed, packed with numerous small spermatophores. Terminal

organ small (TOI), plump, sansage-shaped, distinctly looped; diverticulum appears absent. Spermatophores II

short ("small") (SpLI 132); horn straight or with few widely open coils.

Eggs small (capsule 3-4 mm long), stalks long, braided together, eggs laid in festoons, i

Skin f'mn, smooth or textured with tessellate pattern of low relief, inflated or raised patches ("blisterlike welts"); 4 primary papillae in diamond pattern on dorsal mantle; 1 primary papilla on mid-posterior I

dorsal mantle; 1primary papilla over each eye. Color in life reddish on dorsal surfaces of head mantle and

arms, with darker red- brown reticulate pattern; often mottled with white and with row of white spots down

each side of arms; paler ventrally, often orangish; dorsal mantle white spot complex present; frontal white

spot complex present; patch and groove system present, patches small, round or circular; bluish iridescence •

around eyes. Color in alcohol mouse gray to benzo-brown, mottled or reticulated with slate or blackish

brown; ventral mantle and oral surfaces of arms avellaneous to cream buff. Ink reddish or red-brown. I

Hatchlings planktonic, small (ML 1.7-2.0 ram); mantle globose; arms short, subequal with 4 suckers; I

arms with chromatophores in 2 rows; funnel with 2+2 chromatophores; dorsal mantle barren in mid region,

with simple band of 6 chromatophores on anterior margin and cap of 6-8 chromatophores in posterior am

region; ventral mantle densely covered with 30-40 chromatophores (6-7 across); dorsal head with 2 + 4 + 4 |

pattern; visceral chromatophore number unknown; gold iridophores around eyes.

Type Locality and Type Specimens. MEXICO, Baja California del Norte, South Coronado Island, •

off south end of island, [26°07'N, I I I°17'W], 15-17 fm [27-31 m]; coll. RIVOrca, station H49-167. Holotype II

--male (mature), 32 mm ML; USNM 815709, [SSB 969]; preserved in alcohol, in good condition. Paratypes

--1 female (immature), 23 mm ML; USNM 815710 [SSB 968; from same locality as holotype].-- 3 males •

+ 5 females + 5 juveniles (mature - juveniles), 11-30 mm ML; USNM 81571 [SSB 970; from same lot as II

holotype].--2 females (age ?), ML unknown; [SSB 972; location unknown, presumed not extant].--2 females

(immature), 12 and 23 mm ML; USNM 815712 [SSB 976; from same locality as holotype]. II i

Distribution. Known to range from the mouth of the Gulf of California, Mexico to the Gulf of II

Alaska. Widely distributed vertically from intertidal to shallow subtidal, 0-300 m, on soft sand/mud bottoms

and in rocky areas inshore and in intertidal areas.

Etymology. Name derived from the Latin rubeo meaning "I redden" in reference to the species'

conspicuous red color.

Common Name. Red octopus. I

Discussion. Diagnosis based on Berry's (1953) original diagnosis, his manuscript notes,

measurements and figures in the archives at the USNM, discussions with Berry while he was alive; III

observations of live animals and reference to color photographs of live animals (see Packard and Hochberg, |

1977).

The relationship of rubescens from the Eastern Pacific and Hoyle's hongkongensis from Japan in •

the Western Pacific needs to be compared in detail to determine if they are related or represent the same II

species.

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220 I
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Figure 6.7. Octopus rubescens: view of living specimen. (from Morris, Abbott, and Haderlie, 1980).

I

I Octopus rubescens is the most common species of octopus in the Eastern North Pacific. The species

typically occupies a depth range intermediate between O. bimaculatus/bimaculoides inshore and O.

califomicus in deeper water offshore.

i Biology. The biology of rubescens was briefly reviewed Hochberg and Fields (1980) and more

fully by Hochberg (in press). The species lives in rocky areas or inhabits large dead gastropod or barnacle

i shells, movingempty offshore bottles and cans. Octopus rubescens has a life span of 12-18 months. It is a migratory species, in winter months. Mating occurs at depth in the spring followed by an onshore migration

prior to spawning. Depending on the size of the female from 20-50,000 small eggs are laid in the spring and

i fall. Color patterns have been studied by Warren et al. (1974), Dorsey (1976) and Packard and Hochberg (1977). Planktonic hatchlings and later stage paralarvae and juveniles have been described by Young (1972),

Green (1973), Brocco et al. (1974), Mills (1983), Osborn (1990) and Hochberg et al. (1992). Paralarvae are

i thought to remain in the plankton for 1-2 months. Juveniles up to 20 mm ML have been reported in the

i 221
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plankton in large numbers (Young, 1972; Robison, pers. comm.). Octopus rubescens is nocturnally active U

and feeds principally on crustaceans, mollusks and occasionally fishes. The species is known to bite when

handled or disturbed and is capable of injecting a potent toxin via the salivary proboscis (Halstead, 1949; •

Berry and Halstead, 1954; Oglesby, 1972; Ballering et al. 1972). l

Parasites. The presence of species specific parasites, especially dicyemid mesozoans often aids in

the identification of this octopus (for review of parasites and literature see Hochberg, 1990). An unusual •

dinoflagellate parasite which attaches to and destroys spawned eggs has recently been noted by Osbom !1

(1990).

Octopus ealifornicus Berry, 1911 H

Figure 6.8 I

Polypus californicus Berry, 1911:590.

Material Examined. California: Paratype--male (mature), 77 mm ML; CAS IZ 017971 [SSB 131; n

su, CASIZ type 460].--2 females (submature), 55 and 62 mm ML; San Diego County, Soledad Mtn., SE n

3.7 mi off Pt. La Jolla, 193-227 fm [353-415 m]; coll. USBCF Albatross, station 4323, 7 March 1904;

CASIZ 024403 [SSB 135, SU 2133, CAS hypotype 530; voucher for Berry 1912].--1 female (submature), 1

60 mm ML; San Diego County, S 82°E, 10 mi offPt. Loma Light House, 260-284 fm [475-519 m]; coll. I

USBCFAlbatross, station 4369, 16 March 1904; CASIZ 024404 [SSB 113, SU 2118, CAS hypotype 532;

voucher for Berry 1912].--4 juveniles, 11-22 mm ML; San Diego County, S 81°E, 6.2 mi off Pt Loma Light m

House, 130-158 fm [238-289 m]; coll. USBCF Albatross, station 4365, 16 March 1904; CASIZ 031371 i

[SSB 126, SU 2134; voucher for Berry 1912].--1 male (mature)+ 2 females (mature/immature), 65 and 37,

77 mm ML; Santa Barbara Channel, 301 °true, 9 mi off west point of Santa Cruz Island, 34°09'N, 120°04'W; am

coll. G.S. Myers, R.L. Bolin and party, Crocker-Stanford Deep Sea Expedition, P/Y Zaca, station 10, 13

September 1938; CASIZ 031244 and 032607 [split lot].--2 males (mature), 65, 70 mm ML; San Luis

Obispo County, 50° true, W 114S off San Luis Obispo Bay Light, 125-160 fm [229-293 m]; coll. M/V n

N.B.Scofield, station 116 [NBS 50B-49], 21 October 1950; CASIZ 031363.--1 male (mature) + 4 females

(immature), 65 and 30-50 mm ML; San Luis Obispo County, 10 mi SW of Avila, 100 fm [183 m]; colI. E.S.

Herald and party, R/V Searcher, 19 October 1970; CASIZ 031364.--1 male (mature), 75 mm ML; Channel

Islands, Santa Catalina Island, off Isthmus Cove, 33 °28'N, 118°26'W, 107-130 fm [196-238 m]; coll. G.S.

Myers, R.L. Bolin and party, Crocker-Stanford Deep Sea Expedition, P/Y Zaca, station 25, 16 September

1938; CASIZ 031365.--I female (juvenile), 31 mm ML; San Luis Obispo County, W of Pismo Beach, 85- i

110 fm [155-201 m]; coll. Ripley and Phillips, M/V N.B. Scofield, station 122 [NBS 50B-55], 23 October II

1950; CASIZ 031367.--1 male (immature), 46 mm ML; San Luis Obispo County, 7-10 mi SW of Pt. San

Luis, 70-110 fm [128-201 m]; coll. G.D. Hanna, M/V N.B. Scofield, station 139-149 [NBS 50B-72-82], 5- I

7 November 1950; CASIZ 031368.--2 males (immature) + 1 female (immature), 38, 40 and 46 mm ML; !1

Channel Islands, 152° true, 8 mi off Anacapa Island, 128 fm [234 m]; coll. D. Goodwin, IvlIVN.B. Scofield,

station 168 [NBS 51B-7], 17February 1951; CASIZ 031370.--2 males (immature), 37, 44 mm ML; Monterey •

Bay, 42 ° true, 10 mi off Santa Cruz, 220-236 fm [402-432 m]; coll. D. Goodwin, M/V N.B. Scofield, station l

175 [NBS 51B-14], 19 February 1951; CASIZ 031372.--1 male (juvenile), 20 mm ML; Santa Barbara

County, Santa Barbara Channel, S of Goleta Pt., 34°15.3'N, 119°39.4'W, 141-228 fm [258-417 m]; coll. T. •

Iwamoto, M/V Commando, station TI-77-15 to 17, 7 July 1977; CASIZ 061054.--1 male (immature) + 2 I

females (immature), 37 and 31, 35 mm ML; Santa Barbara County, Santa Barbara Channel, S of Goleta Pt.,

34°20.0'N, 119°50.7'W, 141-146 fm [258-267 m]; coll. T. Iwamoto, M/V Commando, station TI-77-15, 7 I

July 1977; CASIZ 069422. I

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I Description. Animals medium size (TL 195-375 mm) short, compact and plump; body medium

size (ML 50-100 ram); mantle muscular, broadly ovoid, almost as wide as long (MWI males 70-80, females

i 64-I01). Stylets present, non-mineralized. Head broad, about as wide as mantle (HWlw males 75-87, females 61-86); neck slightly constricted; eyes very large, prominent, bulging in live animals. Pallial aperture

wide (PAIw 60-80). Funnel large, stout, bluntly tapered (FL129-53); free about half its length (FFLI 51-79).

Funnel organ VV- shaped, limbs thick, outer limbs half as long as median limbs.

I Web moderately deep (WDI 25-31), well developed, capable of considerable in life; web extends

along ventral side to tips of all arms; dorsal and ventral sectors always shallowest, web formula commonly

I B=C=D.A=E. tips; subequal, Arms arm formula short (ALI typically 61-74), 2.I.3.4. 2.5-3Suckers times MLmoderate (AMI 269-360); to large sizestout, (SDInmuscular, 7-11); raised taperingaboveto fine arm

surface, infundibulum flared, radial grooves indistinct; proximal 2-3 suckers uniserial; enlarged suckers

i (sucker number 14-23) on all arms of mature males only (SDIe 9-18). Hectocotylized arm right third arm (HAMI 196-247); shorter than opposite arm (OA170-81); spermatophore groove deep, white, interbrachial

web not thickened; with 47-53 suckers. Copulatory organ medium size (LLI 10-22); ligula conical, narrow,

i groove long, Gills deep with with 12-1350-60 lamellae transverse per outer folds; demibranch; calamus minute gills moderately (CLI 2-6),long pointed. (GLI 24- 43).

Beaks typical. Radula not described. Digestive tract with small anterior salivary glands; posterior

I salivary glands large, leaf like; esophagus long, narrow; anterior crop inflated, without anterior diverticulum; posterior crop wider than esophagus; stomach tripartite; caecum with single tight coil; intestine differentiated

with expanded mid section; anal flaps large, stout. Ink sac small, lying in shallow groove in digestive gland.

I Male reproductive tract and spermatophores not described. Terminal (penis) large (PLI 14-

organ

28), diverticulum moderately large (DLI 47-75).

i Mature female, ovary large, ovoid; proximal oviducts joined in common duct where enter ovary,

short free section; oviducal glands large, spherical, uniformly dark in color, braiding chambers absent;

distal oviducts extend almost to anus, curved with expanded tips. Eggs large (capsule 14- 17 mm long),

attached singly to substrate by short stalk (3-5 mm long). Hatchlings benthonic.

I Skin in life appears smooth; in preserved specimens mantle, head and arm bases densely covered

with large stellate tubercles or nodules; raised papillae uniformily distributed across surface of dorsal mantle,

I head and arms; single large unbranched papilla over each eye. Color in life uniform orange brown or pinkish red-brown dorsally; ventral surfaces of mantle, head and arms lighter than rest of body; eyelids gold, often

with green iridophore sheen. Patch and groove system present; patches circular with faint dark reticulation.

Frontal white spot complex faint; dorsal mantle white spots absent. Variegated or mottled color patterns

I never produced. Ink black.

Type Locality. California, vicinity of San Diego, [Point La Jolla, off Soledad Hill, SE 4.4 mi], 191-

I 292 mm fms ML];[349-534 USNM 214321 m]; coll.[SSUSBCF B 131];Albatross no longer , station extant.4325. Paratypes Holotype- Male -- Male (mature), (mature), 265 mm308 mmTL [77TL mm[89

ML]; CASIZ 017971 [SSB 131; CASIZ type 460]. - Male; USNM 214312b [SSB 131]; no longer extant.

I Mexico Distribution. A boreal deep water species reported to occur from Punta Eugenia, Baja California, to the Gulf of Alaska (see discussion below). For the purposes of this paper the distribution is

limited to the eastern North Pacific. Lives on soft mud and muddy sand bottoms at depths ranging from

I 100-900 m, highest densities occur between 200-500 m. Etymology. Named for the State of California.

Common Name. California bigeye octopus !

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Figure 6.8. Octopus californicus: A, ventral view of large male, San Diego, California; B, dorsal view of holotypc i

specimen (male). (after Berry, 1912a).

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i Acknowledgments

I the Michael local Swee octopus ney species. (USNM) Henry providedChaney references and Paul andScot Michael t provided Lang editorial shared useful assistainforma nce, andtionMaorin esever Murphy al of

scanned and modified the illustrations.

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of the follicular epithelium. Tsitologiya 11:401-409.

I Aizenshtadt, J.B. 1971. Cytomorphological study of egg follicles in the cuttlefish. 11.The secretory function

of the follicle epithelium. Tsitologiya 13:956-964.

I Aki_rnushkin, I.I. 1965. Cephalopods of the U.S.S.R. [Translation of 1963 Russian edition by A. Mercado] Jerusalem. 223 pp.

i Aldrich, cephalopod M.M., V.C.radulae. Barber,Canadian and C.J.Journal Emerson. of Zoology 1971. Scanning 49:1589-1594. electron microscope studies of some

Anderson, M.E. 1978. Notes on the cephalopods of Monterey Bay, California, with new records for the

I area. Veliger 21(2):255-262.

Anderson, R.C. 1987a. Cephalopods at the Seattle Aquarium. International Zoo Yearbook 26:41-48.

I Anderson, R.C. t987b. Field aspects of the sepiolid squidRossiapacifica (Berry, 1911). Western Society of Malacologists, Annual Report 20:30-32.

I Anderson,Meeting, R.C. 1991. American AquariAssociation um husbandry Zoological of the Parks sepiolidandsquid, AquariRossia ums. pp. pacifica 206-211. . Proceedings, [see also Program Annual

and Abstracts, Joint Annual Meeting, American Malacological Union/Western Society of

i Malacologists. p. 26 (Abstract)]. Anderson, R.C. and R.L. Shimek. 1994. Field observations of Rossia pacifica (Berry, 1911) egg masses.

Veliger 37(1):17-119.

I Anderson, R.C. and J.E. Vanderwerff. 1989. In pursuit of the suburban squid. Sea Frontiers 35(3): 165-169.

Antonelis, G.A. and C.H. Fiscus. 1980. The pinnipeds of the California Current. California Cooperative

I Oceanic Fisheries Investigations (CalCOFI) Report 21:68-78.

Arkhipkin, A.I. 1995. Statolith microstructure and maximum age of the sepiolid Rossia pacifica (Cephalopoda,

i Sepioidea) in the northern part of the North Pacific. Sarsia, 80: 237-240.

i Avdeev, Pacific. G.V. 1982. Parazitologiya New species 16:107-116. of harpacticoid [In Russian; copepods, Translation parasitesavailable of octopuses from F.G. in the Hochberg]. northwestern

Avdeev, G.V. 1986. New harpacticoid copepods associated with Pacific cephalopods. Crustaceana 51:49-

ii I 65.

Ballard, R.D. 1977. Notes on a major oceanographic find. Oceanus 20(3):35-44 [Summer].

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Berry, S.S. 191 la. Preliminary notices of some new Pacific cephalopods. Proceedings of the United States

National Museum 40(1838):589-592.

Berry, S.S. 191 lb. Notes on some cephalopods in the collection of the University of California. University i

of California Publications in Zoology 8:301-310.

Berry, S.S. 1912a. A review of the cephalopods of western North America. Bulletin of the Bureau of Fisheries

30(1910):267-336. I

Berry, S.S. 1912b. A catalogue of Japanese Cephalopoda. Proceedings of the Academy of Natural Sciences,

Philadelphia 64:380-444. I

Berry, S.S. 1913. Notes on some west American cephalopods. Proceedings of the Academy of Natural

Sciences, Philadelphia 65:72-77.

Berry, S.S. 1916. Cephalopoda of the Kermandec Islands. Proceedings of the Academy of Natural Sciences i

of Philadelphia 68:45-66.

I

Berry, S.S. 1921. Notes on some Japanese cephalopods. - A review of Sasaki's "Albatross" report. Annals I

and Magazine of Natural History, (ser. 9) 8:351-353.

Berry, S.S. 1925. Cephalopoda. In: Report of the Canadian Arctic Expedition 1913-18. Vol. VIII: Mollusks, B

Echinoderms, Coelenterates, Etc., Pt. B. F.A. Acland: Ottawa. Pp. 3-8. II

Berry, S.S. 1953a. Preliminary diagnoses of six west American species of Octopus. Leaflets in Malacology II

1:51-58. |

Berry, S.S. and B.W. Halstead. 1954. Octopus bites - a second report. Leaflets in Malacology 1:59-94.

Brocco, S.L. 1971. Aspects of the biology of the sepiolid squid, Rossia pacifica Berry. Master's Thesis, I

Department of Biology, University of Victoria, Victoria, B.C., Canada. 151 pp.

Coan, E.V. and A.E. Bogan. 1987. The Recent invertebrate taxa described by William More Gabb 1839- i

1878. Proceedings of the Academy of Natural Sciences, Philadelphia, 140: 273-284.

Dorsey, E.M. 1976. Natural history and social behavior of Octopus rubescens Berry. Master's Thesis, i

Department of Zoology, University of Washington, Seattle. 44 pp. |

Evans, R.G. 1975. The results of an exploratory fishing cruise for Loligo opalescens in southern and central

California: June 5-25, 1974. Moss Landing Marine Laboratory Technical Publication 75(2): 26 pp. I

I

Fields, W.G. and K.A. Thompson. 1976. Ultrastructure and functional morphology of spermatozoa of Rossia

pacifica (Cephalopoda, Decapoda). Canadian Journal of Zoology 54:908-932.

Fisher, W.K. 1923. Brooding habits of a cephalopod. Annals and Magazine of Natural History, (ser. 9) i

12:147-149.

Fisher, W.K. 1925. On the habits of an octopus. Annals and Magazine of Natural History, (ser. 9) 15:411- !

i

414.

Gabe, S.H. 1975. Reproduction in the giant octopus of the North Pacific Octopus dofleini martini. Veliger i

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I

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i 231
IIIIIIIIIIIIIIIIII

232i
Appendix

Lists and Maps of Stations

Table A.1. Position of soft-substrate stations taken during the Phase I Reconnaissance.

Station Latitude Longitude Depth

(m)

1 35°27.86"N 121°05.33'W 98

2 35°27.70'N l 21°06.52'W 200

3 35°27.07'N 121o10.20'W 291

4 35026.56'N 121°14.93'W 393

5 35025.77'N 121°21.69'W 585

6 35°20.88"N ] 20°59.62'W 109

7 35o20.65'N 121°02.57'W 197

8 35°20.00"N 121°06.58'W 308

9 35Ol9.48'N 121°10.06"W 398

t0 35o18.28"N 121°18.65'W 591

11 35°17.80'N 121°22.1YW 690

12 35°15.03'N 120°57.31'W 98

13 35o14.54'N 120°59.77"W 197

14 35°14.15'N | 21 °02.04"W 299

15 35*13.98'N 121°04.54"W 393

16 35o12.23'N 121°16.29'W 591

17 35o11.61"N 121°22.55'W 654

18 35o09.08'N 120°56.55"W t97

19 35o08.93'N 120°59.66'W 296

20 35°15.72'N 121°04.68'W 396

21 35°06. I I'N 120°44.82'W 49

22 35o05.85'N 120°50.23"W 99

23 35°05.60'N 120°55.18'W 195

25 35o05.07"N 121°00.75"W 390

26 35°04.38"N 121°15.99'W 590

27 35°04.30'N 121°19.27"W 611

28 35°04.22'N 121°19.65"W 603

30 34o54.19'N 120°47.07'W 98

31 34o53.76'N 120°52.96'W 200

32 34°53.56'N 120°56.8 I'W 297

33 34053.43"N 120°59.66'W 396

34 34°53.15'N 121°04.40'W 492

35 34o52.96"N 121°10.30'W 548

36 34°52.77'N 121°15.37'W 492

38 34°49.8 I'N 120°52.66'W 197

39 34°49.53'N 120°56.85'W 294

40 34049.24'N 121°00.8 I'W 392

41 34o48.35"N 121°19.14'W 495

42 34o48.04"N 120°47.50"W 1043

43 34o46.59'N 120°52.92'W 197

45 34°44.91'N 120°59.59'W 395

46 34°41.22"N 121° 13.56'W 597

47 34°41.99'N 121°10.81'W 378

48 34°45.1 I'N 120°52.85'W 196

49 34°45.03'N 120°56.31'W 290

50 34°37.80'N 121°01.66'W 591

52 34o39.56'N 120°47.64'W 98

53 34°37.69"N 120°50.38"W 196

54 34o36.57'N 120°52.02'W 396

55 34°33.66'N 120056.3 I'W 590

56 34°30.32'N t21001.02'W 900

233
!

Table A.1 (Continued)

Station Latitude Longitude Depth i

(m)

I

58 34°34.35"N 120°45.18'W 99 •

II 59 34°33.65'N 120"47.18"W 216

60 34°33.25'N 120°48.34'W 275

61 34°33.0 I'N 120°48.89'W 345

62 34°30.46'N 120°52.13'W 582 •

63 34°26.29'N 120°58.08'W 930 I

64 34°33.15"N 120°40.90'W 59

65 34°31.27'N 120°43.27"W t07

66 34°30.46'N 120°44.55'W 201 i

67 34°30.29'N 120°45.50'W 282 I

68 34°29.24'N 120°45.99"W 390

69 34°22.88'N 120°54.20"W 927 n

70 34°29.67'N 120°43.70'W 200 •

71 34°29.04"N 120°44.01"W 306

72 34°28.4 I'N 120°44.76'W 401

73 34°28.21'N 120°36.8tYW 98 •

74

75

34°26.84

34°26.08

'

'

N

N

120

120

°

°

38.6

39.65

I

"

'

W

W 201

293 B

76 34°25.59'N 120°40.98'W 387

77 34°22.62'N 120°44.02'W 578 •

78 34"18.78'N 120°49.30'W 762 U

79 34°24.12'N 120°28.32'W 98

80 34°22.86'N 120°28.34'W 196

81 34°21.26'N 120°28.83'W 294 •

82 34°18.7 I'N 120°29.55"W 394

83 34°17.20'N 120°30.20'W 444

84 34° 13.54'N 120°31.19'W 394

85 34°25.88"N 120 °16.3 I'W 113 •

86 34°24.45'N 120° 17.02'W 197

87 34°21.60'N 120° 17.11'W 299

88 34°17.89'N 120016.86"W 393 •

89

90

34

34°

°

09.44

13.79

'N

'N 120

120

°

°

16.56

16.30

'

'

W

W

471

375 B

91 34 °11.73'N 120°07.43'W 540

92 34°08.70'N 120°07.50"W 444 •

l

93 34°07.63'N 120°07.5 I'W 357

96 34°22.9 I'N 120°05.42'W 296

94 34°24.54'N 120°05.47'W 96 i

95 34°23.70"N 120°05.47"W 198 •

97 34°22.28"N 120°05.49'W 393

98 34°12.87"N 120°05.59'W 561

99 34° 1!.22'N 120°05.86'W 540

100 34°08.67'N 120°05.50"W 443 •

101 34°07.5 I'N 120°05.65'W 357

102 34°59.71'N 120°48.22'W 99

103 34°59.63'N 120°53.56'W 197 •

|

104 34 °59.45'N 120°56.49'W 294

105 34°59.23"N 120°59.60'W 392

106 34°58.95"N 121°04.42"W 492

107 34°58.65'N 121°15.08'W 573 •

l

108 34°58.21'N 121°17.88'W 492

Note: Sample labels from the Soft-subslrate stations have several identification codes which include a station number, sample n

replicate number, and analysis type. These are as follows: 001 to 200 = the range of station numbers; BSS = Benthic •

Sediment Single (i.e., a non-replicated station); BSR = Benthic Sediment Replicate (three replicates taken at this station); BSV =

Benthic Sediment Variance (subsamples); 01-09 = replicate numbers; TX = a taxonomy sample. Sample labels having the

designation BRA, represents a sample from rocks taken as part of the hard bottom survey, i

234 i
I

I ' !

'"2 1%,-+_. Pt.--__r+,_RO. :_1 .... ' : : .: i :-

I " " _: " "" • " " " 8 " :"

5 • " _ " _ " " " " • o

• , "".+ + k • " " _ " • CALIFORNIA

• 20 li__(,,..+_,. +_

I ': '+" "'+'"'" 19 '"+$ _ + m°lO'N "

° °". R.2 RI

U 2, 2+ _ "-" "+ • t

: " +. /

I tm ,07 '_.._o. ; o " /

• . ,m +._ ._ }

R9 ': C>

+ 35 34 ) " 32 31+i _ 30" [ Pt.SAL

I " ee7 33 !,: o "_

41 • • _ ._ I

• +_ +2 l

I 4+"It O p. e,_ " -R4... _, PURISlMA 1% 49

10_, +, 46 47 :_D,_ /

"'--,.'_... • • oP_ _._ _ ]

, 54 it.

1% _GUEU.O

" .... ._ 61 o- .:'_6,5

.................... O.--_ - 67 ," w X

: 62 m, __ eep66 __ _ I% CONCEPTION

I 63 ',,e " •

'"......... "12 71.......... oe74---.-. • 85 94

_..: ,% 7s . ._ .....ores............ tgs

,* "....e+a......... 200 • % ....

"- 08:7 o9- /

i . _ om

O78 • 88

,.. 083

I ,,' @89

: 084 098

91 •

eW

-- 34DlO'N :

... I<3b'Y 090 92 • olQO

.... 93 • • 101

!

Figure A.1. Map showing location of soft-substrate stations from the Phase I Reconnaissance and Phase II

i Monitoring Programs.

I

n 235
!

_b|e A_. _afion of soft-subs_ stations _n d_g _e _ase H Momt_g _o_. I

area

Sradon Latitude _n_mde Dep_ •

(m)

I

R-1 35°05.83'N 120°49.16_V 91 •

R-2 35°05.5_N 120°53.40%V 16t

R-3 35°05.3_N 121°_.9_W _9

R_ M°43.0I'N 120°47.3ffW 92 I

|

R-5 _°42.69'N 120°50.83%V 154

R-6 34°41 ._ 120°57.9_W 410

R-7 34°52.90_ 121°I0.3_w 565

R-8 34°55.30_ 120°45.87'W _ •

I

R-9 34°53.68_ 120°59.12%V 410

PJ- 1 34°55.79_ 120°49.9 I'W 145

PJ-2 34°55.32' N 120°49.59'W 142

PJ-3 34056.26 'N !20°49.58'W 138 •

P]-4 34°56.26'N t20°50._'W 150

PJ-5 34°55.32'N 120°50.24'W 152

PJ-6 34054.7 I'N 120°49.91_V 148 1

PJ-7 34°55.79'N 120°48._%V 123 •

PJ-8 34°56.87'N 120°49.91%V 142

PJ-9 34°55.79'N 120°51.23%V 169

PJ-10 M°53.63'N 120°49.9 l%V 147 U

|

PJ- 11 _°57.95'N 120049.9 I'W 136

PJ-12 _°55.58'N 120°49.91'W t45

PJ-13 34°56.01_ 120°49.91'W I

PJ- 14 34°55.79_ 120°49.26%V 134

1

PJ-15 34°55.7ffn 120°50.57%V 155

PJ- 16 34°55.03_ 120°48.99%V 130

PJ-17 34°56.56"N 120°48.98'W 126

PJ-18 34°56.56'N 120°50.84'W 158 •

PJ- 19 34°55.03'N 120°50.84'W 167

PJ-20 34°50.38"N 120°49.91'W 148

PJ-21 35°01.23'N 120°51.15_ 143 mira

PJ-22 _°55.25'N 120°49.93%V 143 •

PJ-23 _°56.33'N 120°49.9_W 143

!

_ble A_. Sampling dates of MMS Phase H Monitoring Program. I

Cruise Date I

1-1 October 1986

1-2 January 1987

1-3 May 1987 •

2-1 July 1987 I 2-3 October 1987

2-4 January 1988

2-5 May 1988 n

3-1 Ocm_r 1988

3-4 May 1989 |

236 I
Table A.4. MMS Phase I - _tions of hard-substrate transects.

Station Beginning End Depth

Latitude Longitude Latitude Longitude (m)

1 A/B 34°24.454"N 120°01.876"W 34°24.464'N 120°00.878'W 69-73.5

1 C/D 34°24.076"N 120°00.443'W 34°24.184"N 120°01.481YW 73.5-78

2 A/B 34°11.377"N 120°29.318'W 34°11.289"N 120°28.774'W 110-126

2 C/D 34°10.984'N 120°28.094"W 34° 10.780'N 120°27.554"W 120-123

4 A/B 34°27.539'N 120°40.364'W 34°28.162'N 120°40. 189'W 168-237

6 A/B 34°30.246'N 120°35.555"W 54-63

6 C/D 34°30".421'N 120°3"4.315'W 54-63

13 A/B 34°42'.570'N 120°47.899"W 34°42.107'N 120°48.253'W 92-100

13 C/D 34°42.556'N 120°48.147'W 34°42.974'N 120°47.424'W 88.5-t00.5

14 A/B 34°43.589"N 120°49.093'W 34°42.826"N 120°48.370"W 96-105

14 C/D 34°43.244'N 120°49.406"W 34°42.893'N 120°48.822"W 105-117

16 A/B 34046.544'N 120050.197'W 34°45.912"N 120049.726'W 91.5- 123

17 MB 34°49.382"N 120°50.768"W 34°49._(YN 120°50.688"W 160.5-168

19 A/B 34°47.833'N 120051.425'W 34°47.097"N 120°50.793"W 148.5-177

20 A/B 34°46.470'N 120°50.289"W 34°46.140'N 120°49.885"W 90-130.5

21 A/B 34°47.335'N 120°45.903'W 34°47.548"N 120°46.123'W 75-90

22 A/B 34°50.365'N 120°48.221'W 34°50.990'N 120°48.365'W 114-115.5

23 A/B 34°49.868'N 120°47.393'W 34°50.003'N 120°47.480"W 93-102

25 A/B 35°05.662'N 120°47.562"W 35°06.036'N 120°47.652'W 64.5-72

26 C/D 35°11.586'N 120°55.556'W 35°11.555'N 120°55.233'W 108-111

27 A/B 35°20.906'N 120°59.657"W 35°21.035'N 120°59.603'W 96-126

28 A/B 35°21.539"N 120°59.641'W 35021.867'N 120°59.299'W 96-105

29 A/B 35°27.864"N 121°05.331"W 35°27.805'N 121°05.277'W 102-106.5

Table A.5. MMS Phase II - Locations of hard-substrate photosurvey stations.

Station Latitude Longitude Depth

(m)

PH-E 34°30.26'N 120°42.76'W 119

PH-F 34°30.81'N 120°42.36"W 105

PH-I 34°29.96'N 120°41.68'W 107

PH-J 34°29.82'N 120°41.82"W 117

PH-K 34°29.37'N 120°42.26'W 160

PH-N 34°29.21 'N 120°42.05 'W 166

PH-R 34029.1 I'N 120°42.67'W 213

PH-U 34031.48'N 120043.5 I'W 113

PH-W 34031.52'N 120°45.86"W 195

237
I

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Ill 0 22

19::18"_ 20• 21 PURISIMAPt. I

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3,1P32'N -_.. • GUELLO I

PH_U• PLCONCEFr!O__N_,_ __,

P,..r.w

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/ ....................... 200 ........................

PH-E • PH-I ._ /

PH-R _)m, PH,-N / /

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34o28,N I /

120o44'W

I

Figure A.2. Map showing location of hard-substrate stations from the Phase I Reconnaissance and Phase H

Monitoring Programs. Phase II stations are indicated in the inset. I

I

238 I
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I

The Department of the interior Mission

I As the Nation's conservation the of the Interior has

principal agency, Department responsibi]_y

for most of our nationally owned public lands and natural resources. This includes fostering

sound use of our land and water resources; protecting our fish, wildlife, and biologicaldiversity;

i preserving the environmental and cultural values of our national parks and historical places;

and providing for the enjoyment of life through outdoor recreation. The Department assesses

our energy and mineral resourcesand works to ensure that their development is in the best

interests of alf our people by encouraging stewardship and citizen participation in their care.

i The Department also has a major responsibility for American Indian reservation communities

and for people who live in island territories under U.S. administration.

The Minerals Management Service Mission

primary responsibilities are to manage the mineral resources _ocatedon the Nation's Outer

Continental Shelf (OCS), collect revenue from the Federal OCS and onshore Federal and Indian

lands, and distribute those revenues.

I Moreover, in working to meet its responsibilities,the Offshore Minerals Management Program

administers the OCS competitive leasing program and oversees the safe and environmentalfy

sound exploration and production of our Nation's offshore natural gas, oit and other mineral

I resources. efficient, timely The MMS and accurat Royaltye coManllection agement and Prog disbursement ram meetsofitsrevresponsibilities enue from minbyeralensuring Ieasing the and

production due to Indian tribes and allottees, States and the U.S. Treasury.

I The MMS strives to fulfill its responsibilitiesthrough the general guiding principles of: (1) being responsive to the public's concerns and interests by maintaining a dialogue with all potentially

affected parties and (2) carrying out its programs with an emphasis on working to enhance the

quality of life for all Americans by lending MMS assistance and expertise to economic

I development and environmental protection.

I