NOAA Technical Report NMFS 33 September 1985

Marine Flora and Fauna of

the Northeastern United States.

Echinodermata: Echinoidea

D. Keith Serafy and F. Julian Fell

U.S. DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

National Marine Fisheries Service
NOAA TECHNICAL REPORTS NMFS

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Springfield, VA 22161.
NOAA Technical Report NMFS 33

Marine Flora and Fauna of

the Northeastern United States.

Echinodermata: Echinoidea

D. Keith Serafy and F. Julian Fell

September 1985

U.S. DEPARTMENT OF COMMERCE

Malcolm Baldrige, Secretary

National Oceanic and Atmospheric Administration

John V. Byrne, Administrator

National Marine Fisheries Service

William G. Gordon, Assistant Administrator for Fisheries
The National Marine Fisheries Service (NMFS) does not approve, recommend or endorse any proprietary product or proprietary material mentioned in this publication. No reference shall be made to NMFS, or to this

publication furnished by NMFS, in any advertising or sales promotion

which would indicate or imply that NMFS approves, recommends or

endorses any proprietary product or proprietary material mentioned herein,

or which has as its purpose an intent to cause directly or indirectly the

advertised product to be used or purchased because of this NMFS

publication.
FORWARD

This NMFS Technical Report is part of the subseries, "Marine Flora and Fauna ofthe Northeastern

United States," which consists of original, illustrated, modern manuals on the identification, classification, and general biology of the estuarine and coastal marine plants and animals of the northeastern

United States. The manuals are published at irregular intervals on as many taxa ofthe region as there are

specialists available to collaborate in their preparation.

Geographic coverage of the "Marine Flora and Fauna ofthe Northeastern United States" is planned

to include organisms from the headwaters of estuaries seaward to approximately the 200 m depth on the

continental shelf from Maine to Virginia, but may vary somewhat with each major taxon and the interests of collaborators. Whenever possible, representative specimens dealt with in the manuals are

deposited in the reference collections of major museums of the region.

The "Marine Flora and Fauna ofthe Northeastern United States" is being prepared in collaboration

with systematic specialists in the United States and abroad. Each manual is based primarily on recent

and ongoing revisionary systematic research and a fresh examination of the plants and animals. Each

manual, treating a separate major taxon, includes an introduction, illustrated glossary, uniform originally

illustrated keys, annotated checklist (with information, when available, on distribution, habitat, life

history, and related biology), references to the major literature of the group, and a systematic index.

These manuals are intended for use by students, biologists, biological oceanographers, informed

laymen, and others wishing to identify coastal organisms for this region. They can often serve as guides

to additional information about species or groups.

The manuals are an outgrowth ofthe widely used "Keys to Marine Invertebrates ofthe Woods Hole

Region," edited by R. I. Smith, and produced in 1964 under the auspices of the Systematics Ecology

Program, Marine Biological Laboratory, Woods Hole, MA. After a sufficient number of manuals of

related taxonomic groups have been published, the manuals will be revised, grouped, and issued as

special volumes, which will consist of compilations for phyla or groups of phyla.

CONTENTS

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

External morphology. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Natural history. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Preservation and examination ...................................•............................................ 5

Glossary '" .. . .. . .. 5

Key to the Echinoidea from all depths off the northeastern United States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Annotated systematic list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Selected bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Systematic index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Coordinating Editor's comments 26

iii

Marine Flora and Fauna of the Northeastern

United States. Echinodermata: Echinoidea

D. KEITH SERAFyl and F. JULIAN FELU

ABSTRACT

The echinoid fauna from littoral to abyssal depths off the northeastern United States (Cape Hatteras, NC, to northern Nova Scotia)

comprises 31 species, in 26 genera and 19 families. An introduction to the external morphology, distribution, and natural history is given

along with an illustrated key to the species, an annotated systematic list, and an index. The fauna Includes 17 species with wide-ranging

distributions on continental slopes or abyssal plains. The remaining 14 species occur in shallower waters on the continental shelf or

upper slope. Of these, eight are tropical in distribution with their northern range extending to the northeastern United States and three

are mainly boreal with the northeastern United States at the southern limit of their range. Two species occur only off the eastern United

States and one species is cosmopolitan.

INTRODUCTION

The Echinoidea comprise sea urchins, sand dollars, and heart

urchins. They are echinoderms with the radial canals of the water

vascular system arranged meridionally, and a skeleton composed

of fused plates (except in the Echinothurioida). Echinoids have

either a pentamerous radial symmetry (regular urchins) or a

bi lateral symmetry imposed upon the radial pattern (irregular

urchins).

The Echinoidea have a relatively stable nomenclature as a

result of the work of several dedicated specialists over the last 120

yr. Only a small number of new species are described each year.

There are approximately 955 extant species worldwide; 156 are

known from the North Atlantic. Echinoids occur from the intertidal to the abyss in all seas. This manual covers the echinoids

which occur in North American seas between Cape Hatteras, NC,

and northern Nova Scotia at all depths. The number of nominal

fossil species is several times greater than the number of extant

ones.

EXTERNAL MORPHOLOGY

The rigid calcareous skeleton of echinoids makes it possible to

collect most species intact and accounts for their prevalence a,

fossils. The classification of echinoids is based mostly upon external skeletal features. The skeleton is an endoskeleton composed of

calcium carbonate in the form of calcite, which includes about

4-12% magnesium carbonate. The skeletal material is not solid,

but is rather a porous matrix. Its internal space is about 50% by

volume and contains mesenchymal cells. The shell, or test, is

essentially a hollow ball composed of 20 vertical columns of

plates, rigidly attached to each other in most species (Fig. IA-B).

There are five ambulacra corresponding to the position of the internal radial water vessels, and each ambulacrum is formed by two

vertical columns of plates through which extend the tube-feet.

Five interambulacra alternate with the five ambulacra and these

also consist of two vertical columns of plates. Sutures mark the

adjoining margins of the plates with a faint line or groove.

1Department of Biology, Southampton College, Southampton, NY 11968.

'Department of Zoology, University of Maine, Orono; present address: 405 Vancouver Street, Victoria, B.C. V8V 3T4, Canada.

The lower ends of the columns do not meet at a point, but stop

short, leaving a circular hole on the lower (oral) surface of the test.

This hole is covered by a membrane called the buccal membrane

or peristome in the center of which is located the mouth. In the

orders Cidaroida and Echinothurioida, unfused ambulacral plates

cross the peristome to the mouth, and each bears a tube-foot. In

other regular urchins buccal tube-feet, specialized for feeding, are

arranged in a circle around the mouth, one pair to each ambulacrum. In regular echinoids (except Cidaroida) outpocketings of the

coelom form five pairs of compensation sacs (gills) which protrude from peristomal notches.

Five teeth protrude through the mouth; these are mounted in a

complex jaw structure called Aristotle's lantern. The lantern has

proved to be evolutionarily conservative making it an important

feature in classification above family level in those groups that

possess one.

Test shape is characterized by a number of terms such as low,

globular, conical, hemispherical, arched, and others. Descriptions

of echinoids usually include a statement on the shape of the test,

but this character should never be used alone to key out a species

as it can vary even within a species.

Each ambulacrum terminates adapically in a single ocular plate,

and each interambulacrum terminates in a single genital plate.

The ring of five ocular plates alternating with the five genital

plates form the apical system (Fig. IC). In regular urchins the

periproct and anus are within the apical system. Each genital plate

has a genital pore for the discharge of eggs or sperm. One of the

genital plates functions as the madreporite or sieve plate and is

usually enlarged and covered with small pores.

Each ambulacral plate carries one tube-foot which may vary

considerably in form and function. Tube-feet can function in

respiration, locomotion, reception of stimuli, burrowing, feeding,

or any combination of these. Each tube-foot connects to the radial

canals within the test by a pair of adjacent pores. Simple ambulacral plates (Fig. 2A) have one pore-pair and occur in the cidaroids

and all the irregular echinoids. Compound ambulacral plates (Figs.

2B-F) have 2 to 16 pore-pairs since they are formed by the fusion

of 2 to 16 simple plates. Most regular echinoids have compounded

ambulacral plates which enable the tube-feet to be concentrated

in certain areas (e.g., near the mouth). Compounded ambulacral

plates are also capable of bearing larger spines than simple plates.
AMBULACRUM --

ZONE OF PORE PAIRS

~-------- OCULAR PLATE (EXSERT)

-+--------- GENITAL PLATE

.-t--------GENITAL PORE

~---------- OCULAR PLATE (INSERT)

.-------- OCULAR PORE

SUTURE -------J.~

AMBULACRUM APICAL SYSTEM -----.ltrl~~~~~~~~~~~~B

INTERAMBULACRUM ---............

BUCCAL MEMBRANE

BUCCAL PLATE

PERISTOME

TEETH & MOUTH

PERISTOMAL NOTCH

Figure I.-External features of regular urchins. A, oral surface of Strongylocentrotus droebachiensis; B, aboral surface of Arbacia punctulata; C, apical

system of S. droebachiensis.

2
G .'

<!l .. .. ( 0 ., o....;;'\~ 0

0 G~~ .'

0

c

. .. '0'·'--'. ..

••

E

Figure 2.-Ambulacral plates. A, simple plates orthe Cidaroida; B, diadematoid

type of compound plates (middle plate enlarged) seen in Caenopedina; C, ar·

bacioid type of compound plates seen in Arbacia; D, echinothurioid type of compound plates seen in Araeosoma; E, echinoid type of compound plates (lower

plate enlarged) seen in Echinus; F, echinoid type of compound plates seen in·

Strongylocentrotus.

There are four forms of compound plates, named for characteristic

orders. Diadematoid type compound plates are composed of three

primary plates (in contact with adradial and perradial sutures)

with the middle one the largest (Fig. 2B). Arbacioid type plates

have the middle primary plate so enlarged that the other plates

become demiplates, no longer in contact with the perradial suture

(Fig. 2C). Echinothurioid type plates are composed of a large

primary plate and two small included plates between the primary

plates (Fig. 20). Echinoid type plates have three or more elements

with the adoral and adapical plates being primary plates and the

remaining ones being demiplates (Fig. 2E-F). The adoral primary

plate is always the largest.

Plates of the test bear rounded tubercles which carry the spines.

Each tubercle consists of a raised central boss capped by a smooth,

shiny, hemispherical mamelon (Fig. 3). The mamelon may have a

small hole in the top, in which case it is termed perforate.

Mamelons lacking this hole are imperforate. The upper edge of

the boss surrounding the mamelon may be indented (crenulate) or

smooth (noncrenulate).

·Spines vary considerably in form and function. They are used

for locomotion, protection from predators and the environment,

feeding, and burrowing. In burrowing forms, a dense covering of

fine spines keeps sand and mud off the test, essentially surrounding the test in a jacket of water. Spines form a ball-and-socket

joint with mamelons and are moved by a ring of radially arranged

muscles at the base of the spine. Relatively unspecialized spines

may be primary (largest), secondary (small to medium), or miliary

3

(hairlike and usually short) depending on relative size. Other

terms are applied to specialized types of spines.

In addition to spines and tube-feet the surface of the lest bears

many small clasping structures, the pedicellariae. Pedicellariae are

of several types and function in defense, feeding, and cleaning.

Although useful for classification and identification, they are not

included in this manual, for special knowledge and techniques are

required for their study.

The irregular (excentric or exocyclic) echinoids (Fig. 4) differ

from the regular echinoids in that the periprocl is displaced from

the apical system into what becomes the posterior interambulacrum. Displacement of the periproct and other modifications impart a conspicuous bilateral symmetry to the irregular echinoids.

Irregular echinoids comprise five distinct orders. Clypeasteroida (sand dollars and cake urchins), Holasteroida (heart urchins), and Spatangoida (heart urchins) include many living

species and they are well represented in waters off the northeastern United States. Holectypoida and Cassiduloida are primarily fossil groups with very few living species worldwide; none

occur off the northeastern United States.

The morphological differences between regular and irregular

echinoids are primarily adaptations to a burrowing existence in

sand and mud. The earliest irregular echinoids arose in the Early

Jurassic (Sinemurian), and 10 million yr later they had developed

all the features necessary to permit them to live infaunally (Kier

1982). Some irregular echinoids live on the surface of the

sediments. Adaptations to burrowing include a loss of compensation sacs (gills) on the oral surface and development of petals on

the aboral surface which serve in respiration. Spines are smaller

and more numerous than in regular echinoids. Aristotle's lantern

is absent in the Cassiduloida, Holasteroida, and Spatangoida and

food gathering is accomplished with spines or specialized tubefeet. Irregular urchins that do not burrow have rudimentary petals

and sparse aboral spine coverage, although the spines may be

greatly enlarged.

Clypeasteroida comprise a large group of about 140 extant

species, two of which occur off the northeastern United States. In

this group five respiratory petals extend from a generally central

apical system. Microscopic pores for accessory tube-feet are

A

c

Figure 3.-Types of primary tubercles. A, imperforate; B, perforate; C, perforate and crenulate.
FRONTAL PETAL------------

INTERNAL FASCIOLE ---------T'ft,~

ANTERO-LATERAL PETALS ---=---jI-- ---"4i~~f;

APICAL SYSTEM --------------+-t --4r1iJ5

PERIPETALOUS FASCIOLE --------+--f---I!

LATERO-ANAL FASCIOLE -----+--I

POSTERO-LATERAL PETALS --=::::::li.-t--t

A

or anteriorly. The shapes of spines vary considerably according to

their position on the test, although adaptations are generally for

burrowing. Burrowing is assisted by waves of spine movements

that begin anteriorly and move posteriorly. Minute spines, or

clavules, have cilia along the shaft and a mucus gland on the end.

These are specialized for circulating water over the surface of the

test and lining the burrows with mucus. Tracts of clavules, or

fascioles, follow characteristic paths over the surface of the test

and are named according to the positions they occupy (Fig. 4).

DISTRIBUTION

Figure 4.-External features of irregular urchins (Spatangolda and

Holasteroida). A, aboral surface; B, oral surface with amphisternous plastron; C, oral surface with meridosternous plastron.

numerous and may occur to varying degrees over the test. Accessory tube-feet are present over wide areas on either side of the

ambulacra and they function to pull and hold sand over the test.

The mouth is central (opposite the apical system) and an

Aristotle's lantern is present. The periproct, 'located on the oral

surface in the posterior interambulacrum, is either near the margin

or near the peristome. In some species the test has slits or lunules

which are used in burrowing and feeding. Most species have

ciliated food grooves on the oral surface; in a few species the

grooves extend to the aboral (upper) surface. The test surface is

densely covered with small miliary spines. Larger primary spines

are relatively few, and several types of pedicellariae are present.

The Holasteroida comprise a small group of heart urchins with

a single large plate (meridosternous) comprising the sternum (Fig.

4C). The mouth is situated anteriorly and there is no Aristotle's

lantern. The apical system is longitudinally elongated or disjunct

and the paired petals are poorly developed or absent. Most species

are found only in deep water and three species occur off the northeastern United States.

The Spatangoida comprise a large group of about 200 species,

of which 8 occur off the northeastern United States. The mouth is

situated anteriorly and there is no Aristotle's lantern. The first

plate of the posterior interambulacrum forms a liplike structure,

the labrum, which projects forward under the mouth. Posterior to

the labrum is the plastron which consists of two (amphisternous)

enlarged, interambulacral plates (Fig. 4B). The periproct is

situated posteriorly, usually where the test surface is vertical.

Petals are present but not all are of uniform size or development.

Whatever the condition of the petals, they are always bilaterally

symmetrical. The tube-feet are adapted for respiration in the

paired petals, for tunnel building and maintenance in the anterior

ambulacrum and around the periproct, and for feeding around the

mouth. The apical system may be situated posteriorly, centrally,

Little is known of the natural history of most echinoids, particularly deep-water species. However, it is possible to predict the

life styles of many species (epifaunal, infaunal) from their morphology and habitat. Regular echinoids are epifaunal on hard or

soft substrates and most shallow-water species « 50 m) feed on

algae or seagrasses. Deep-water forms are more omnivorous and

usually ingest sediments, small invertebrates, or plant fragments

NATURAL HISTORY

With the exception of shallow-water species endemic to

isolated mid-oceanic islands, echinoid species characteristically

are distributed over large geographic and bathymetric ranges. The

majority of species live on the outer continental shelf and slope in

depths> 50 m. Cidaris, Genocidaris, and Plethotae'lia are endemic

to the North Atlantic. Stereocidaris, Araeosoma, Hygrosoma, Phormosoma, Caenopedina, Plesiodiadema, Salenocidaris, Urechinus,

Plexechinus, Pourtalesia, Hemiaster, Aeropsis, Aceste, Schizaster,

Brisaster, Brissopsis, and Echinocardium have worldwide,

moderate to deep-water distributions. The Arbaciidae and Mellitidae are of tropical American origin. Both Strongylocentrotus and

Echinarachnius occur in the North Atlantic and North Pacific.

Only three species, Arbacia punctulata, Strongylocentrotus droebachiensis, and Echinarachnius parma, are common in shallow

water off the northeastern United States.

The echinoid fauna from Cape Hatteras, NC, to northern Nova

Scotia comprises 31 species in 26 genera and 19 families. It includes species which are known to occur or are considered likely

to occur in the study area from the littoral to the deep abyss. The

largest component of the fauna (17 species) consists of deep-water

forms which occur on the continental slope or abyssal plain over

wide ranges of latitude and often on both sides of the Atlantic

Ocean. These species include Stereocidaris ingolfiana, Araeosoma

fenestratum, Hygrosoma petersi, Phormosoma placenta, Plesiodiadema antillarum, Caenopedina cubensis, Salenocidaris variaspina,

Salenocidaris profundi, Echinus affinis, Echinus alexandri,

Urechinus naresianus, Plexechinus hirsutus, Pourtalesia miranda,

Hemiaster expergitus, Aeropsis rostrata, Aceste bellidifera, and

Brissopsis mediterranea. The remaining 14 species uccur in

shallow to moderate depths on the continental shell or upper

slope. Eight of these species (Cidaris abyssicola, Coelopleurus

floridanus, Arbacia punctulata, Genocidaris maculata, Echinus

gracilis, Mellita quinquiesperforata, Schizaster orhignyanus, and

Plethotaenia spatangoides) are mostly tropical in distribution and

are at or near the northern limits of their range in the study area.

Three species (Strongylocentrotus droebachiensis, Echinarachnius

parma, and Brisasterfragilis) are mostly Arctic-Boreal in distribution and are at or near the southern limits of their range off the

northeastern United States. Two species occur only off the eastern

United States (Echinus tylodes and Echinus wallisi) while one

species is cosmopolitan (Echinocardium cordatum) in distributIOn.

B c

F=~~~~==~;====-PERISTOME LABRUM

-~--INTERAMBULACRUM

---t-'r----/---- STERNAL PLATE (=PLASTRON)

-1---1---- AMBULACRUM ----;-1-

SUBANAL FASCIOLE

ANAL FASCIOLE

~;;;:::<'::- - PERIPROCT

4
that have been transported from shallower depths. Most irregular

echinoids are infaunal and burrow through the sediments,

although some species (sand dollars and a few heart urchins) remain epifaunal most of the time. Most species are either surface

deposit feeders ingesting organic-rich detritus, or are subsurface

feeders ingesting sediments as they burrow. Lawrence (1975) gave

an excellent review of feeding in echinoids.

Sexes are separate, and most species shed eggs or sperm into the

water where fertilization occurs. Most species have a planktotrophic echinopleuteus larva. The larva eventually metamorphoses

to form a young echinoid. A few species have direct development

and even fewer brood their young. Sexually ripe individuals can

usually be induced to spawn in the laboratory by injection of 3%

KCl solution through the peristome into the coelom. Electrical

shock to the peristome may also induce spawning.

Echinoids may be kept alive in aquaria for extended periods of

time if the water is kept clean and is of the appropriate salinity

and temperature for the species. Cold-water species must be

maintained in refrigerated aquaria. Most shallow-water regular

echinoids can be fed a variety of algae although they may show

distinct preferences. Large individuals may occasionally eat

smaller specimens kept in the same aquarium. Irregular echinoids

are more difficult to maintain and they should be provided with

the appropriate sediments from their habitats.

PRESERVATION AND EXAMINATION

Echinoids may be fixed and preserved in 10% Formalin or 70%

ethyl alcohol. Specimens in Formalin are best transferred to

alcohol after 1-3 d. After fixation in preservative, echinoids may

be dried. This is the most convenient condition for study and

storage. Colors tend to fade upon preservation, especially if

alcohol is used.

A small portion of the test can be cleaned to observe surface

details. Spines on an ambulacral and interambulacral area can be

removed by hand or with a brush, and organic tissue can be

removed without damage to the skeletal calcite by immersion in a

5% sodium hypochlorite solution (i.e., commercial liquid bleach)

for a few minutes. Calcite may be removed from the soft tissue by

immersion for a week in 3-5% acetic acid. Sutures between the

plates are easy to observe if xylene is applied to a dried specimen

with a small paint brush.

GLOSSARY

Aboral Away from the mouth.

Accessory tube-feet Small tube-feet found in ambulacral and

interambulacral areas of the Clypeasteroida.

Adapical Towards the apical system.

Adoral Towards the mouth.

Adradial Boundary between ambulacral and interambulacral

areas.

Ambulacrum Area of test corresponding to position of radial

water vessel and consisting of two regular vertical columns of

plates. Five ambulacra alternate with five interambulacra.

Amphisternous Plastron of paired plates.

Anus Opening of intestine located within periproct.

Apical system Circle of alternating genital and ocular plates at

aboral pole of test.

Arbacioid type Compound ambulacrai plate composed of three

primary plates in which the middle plate is so enlarged that the

adapical and adoral plates are demiplates.

Aristotle's lantern Complex dental apparatus at mouth.

5

Boss Basal part of raised portion of tubercle.

Buccal membrane Peristome. Covering of aperture at oral pole

of test.

Buccal tube-feet Tube-feet on peristome usually occurring in

single circle of five pairs corresponding to radial position.

Clavules Minute spines with cilia on shaft and mucus gland at

tip. These tightly packed spines occur in lines on the surface of

the test known as fascioles.

Compensation sac Outpouching of coelom often called "gills"

but which function primarily to receive excess coelomic fluid

from retraction of Aristotle's lantern.

Compound plate Ambulacral plate composed of fused plates.

Crenulate Upper edge of boss notched or scalloped.

Demiplate Ambulacral plate which touches adradial suture but

not perradial suture.

Diadematoid type Compound ambulacral plate in the order

Diadematoida where the middle of three primary plates is expanded perradially and adradially.

Echinoid type Compound ambulacral plate in the order Echinoida, where lowest demiplate is the largest.

Echinothurioid type Compound ambulacral plate with a single

large primary plate with two small included plates located between the primary plates.

Exocyclic Periproct located outside of the apical system.

Fascioles Tracts of crowded c1avules for circulating water over

surface of test in spatangoid urchins.

Food grooves Spine-free ciliated grooves on lower surface of

sand dollar radiating from mouth.

Genital plate Single plate at aboral end of each interambulacral

area.

Genital pore Pore on each genital plate for shedding gametes.

Imperforate tubercle Mamelon of tubercule without central hole.

Interambulacrum Area of test corresponding to interradial position, consisting of two regular vertical columns of plates. Five

interambulacra alternate with five ambulacra.

Irregular Informal term for all taxa in which periproct has

moved from within apical system disrupting radial symmetry,

and conferring conspicuous bilateral symmetry.

Labrum First plate at edge of mouth of posterior interambulacrum in spatangoid urchins.

Lunules Holes or notches in mid-ambulacral or mid-interambulacral areas of sand dollars.

Madreporite Enlarged porous genital plate connecting to watervascular system.

Mamelon Smooth raised hemisphere forming central and highest

part of tubercle.

Meridosternous Plastron of single plate.

Miliary Very small spines on Cidaroida and Clypeasteroida.

Noncrenulate Upper edge of boss not scalloped (smooth).

Ocular plate Single plate at terminus or radial canal located at

aboral end of each ambulacrum.

Oculo-genital ring Apical system.

Pedicellariae Small, 2-4 jawed, stalked, clasping structures on

surface of test.

Perforate tubercle Hole in center of mamelon of tubercle.

Periproct Membrane-covered aperture which includes the anus,

located at aboral pole or in posterior interambulacrum.

Peristomal notch Notch for compensation sac located along

margin of periproct.

Peristome Buccal membrane. Covering of aperture at oral pole

of test.

Perradial Having meridional position at midline of ambulacrum.

Petals Structures of aboral ambulacra in which many simple
plates are widened laterally, compressed and crowded longitudinally. Found mostly on burrowing irregular echinoids.

Plastron Shield of enlarged plates of posterior interambulacrum

following labrum on lower surface of spatangoid urchins.

Pore-pair Two adjacent pores on ambulacral plates passing

through the test providing passage between tube-feet outside

and radial canal insIde.

Regular Informal term for all taxa in which periproct is located

within apical system, retaining radial symmetry.

Sieve plate Madreporite.

Simple plate Ambulacral plate uncompounded, bearing single

pore-pair.

Spine Movable elongated calcareous shaft mounted on tubercle

and articulating with it.

Suranal plate First-formed and largest plate of periproctal

system.

Suture Adjoining margins of test plates usually marked by faint

line or groove.

Test Hollow shell composed of 20 regular vertical columns of

plates forming basic skeleton of echinoids.

Tube-feet Part of water-vascular system running from radial

canal, passing through test in the ambulacra and extending into

surrounding water, usually terminating with a su"ker.

TubercuIe Specialized structure on test surface for supporting

spine; includes raised and surrounding flat or recessed parts.

KEY TO THE ECHINOIDEA FROM ALL DEPTHS OFF

THE NORTHEASTERN UNITED STATES

Test flattened, disc-shaped, height 25% or less of diameter 2

Test subglobular to globular, height 40-100% of diameter 3

2 (l) Test rigid. Spines uniformly small, numerous, forming dense covering. Tubercles minute. Petals present. Margin acute 21

2 (1) Test flexible. Primary spines and tubercles present. No petals. Margin rounded 9

3 (l) Test radially symmetrical, circumference approximately circular or slightly pentagonal. Largest spines in distinct

vertical rows. Mouth in center of lower side, teeth (lantern) present. Anus in center of upper surface (Figs. 1,5) 4

:3 (/) Test bilaterally symmetrical, slightly to strongly ovoid. Spines numerous, forming dense uniform covering with

petals present, or few spines and no petals. Mouth towards "anterior" end, teeth (lantern) lacking. Anus in

"posterior" interambulacrum. On lower surface behind mouth posterior interambulacrum modified into shieldlike

plastron (Figs. 4, 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .... 22

B

c

D

Figure S.-Examples of regular urchins. A, Coelopleurus (aboral aspect); B, Salenocidaris (aboral aspect); C, Echinus (aboral aspect); D, Strongylocentrotus (oral aspect).

6
Figure 6.-Examples of irregular urchins. A, Plexechinas; B, Hemiaster; C, Plethotaenia.

c

A B

4 (3) Tubercles perforate (Fig. 7) 5

4 (3) Tubercles imperforate (Fig. 8) 11

:; (4) T"st rigid, height exceeding 40% of diameter. Each interambulacral plate with one primary tubercle . .. ........ 6

5 (4) Test flexible, usually collapsed to a disc upon preservation. Primary tubercles on lower side numerous, reduced or

absent from upper surface (usually >200 m) . . . . . 9

A

Figure S.-Imperforate primary tubercle.

B

Figure 7.-Perforate primary tubercles. A, erenulate; B, nonerenulate.

7
6 (5) Spines hollow, very long, slender, and fragile. Tubercles crenulate. Ambulacral plates simple. grouped in triads.

Color light purple. Test to 15 mm diameter, spines to 120 mm (Fig. 9) . . .. . _ Plesiodiadema antillarum

Figure 9.-Plesiodiadema antillarum

(aboral aspect).

6 (5) Spines solid, robust. Tubercles not crenulate 7

7 (6) Ambulacral plates simple (Fig. lOA) continuing across peristome. Interambulacral plates large (Fig. lOB), few, each

with single primary tubercle and spine 8

7 (6) Ambulacral plates compounded with 3 pore-pairs per plate in diadematoid type (Figs. 2B, 11). Peristome with 5

pairs of buccal plates, otherwise naked. Primary spines of adults long and tapered. Spines pale green, test whitish.

Test to 40 mm diameter _.Caenopedina cubensis

-8

A

Figure to.-Test plates in the Cidaroida. A, simple ambu·

lacral plates; B, interambulacral plate.

8

Figure tl.-Diadematoid type com·

pound ambulacral plates of Caenopedina cubensis.
8 (7) Primary spines smooth and shiny on adults, although smaller specimens may have small spinules. Scrobicular and

secondary spines flattened and broader at base than at tip. Test generally whitish, may have brown tint at apical

system and on vertical sutures. Test to 70 mm diameter (Fig. 12) Cidaris abyssicola

12.-Cidaris abyssicola (aboral

aspect).

8 (7) Primary spines covered with spinules and in large adults they may be "winged" with raised flutes. Scrobicular

spines flattened and broader at base than at tip but secondary spines very tiny and not broader at base than at tip.

Test generally tan to whitish, spines pinkish. Test to 25 mm diameter (Fig. 13) Stereocidaris ingolfiana

Figure 13.-Stereocidaris illgoljialla

(aboral aspect).

9 (2, 5) Compound ambulacral plates on aboral surface of echinothurioid type with two very small included plates lying

between the primary plates (Fig. 14) 10

G •• @ Figure 14.-Echinothurioid

type compound ambulacral

0 •• plates. 0 0 0

e G .- @

9
9 (2,5) Compound ambulacral plates of oral and aboral surface of arbacioid type (Fig. 15C). Test flat below, slightly arched

above. Oral side (Fig. 15A) covered with primary tubercles bearing long, club-shaped spines enclosed in membranous sacs. Aboral surface (Fig. 15B) relatively bare. Color yellowish to brown. Test to 120 mm diameter ...Phormosoma placenta

A 8

Figure IS.-Phormosoma placenta. A, oral aspect; B, aboral aspect;

C, arbacioid type compound ambulacral plates.

c

10 (9) Echinothurioid type compound ambulacral plates on oral and aboral surface (Fig. 16). Each oral primary spine tipped with small white shiny hoof. Interambulacral plates with conspicuous membranous interstices along horizontal

sutures. Color brownish with a trace of purple. Test to 200 mm diameter. Araeosomafenestratum

10 (9) Echinothurioid type compound ambulacral plates on aboral surface (Fig. 17A) and arbacioid type compound ambulacral plates on the oral surface (Fig. 17B). Each primary spine on oral side tipped with large white hoof (most are

broken off in preserved specimens). Interambulacral plates without membranous interstices. Color bright purple.

Test to 200 mm diameter Hygrosoma petersi

Figure 16.-Araeosoma fenestratum

(aboral aspect).

10
A

II (4)

Figure 17.-Hygrosoma petersi. A, aboral aspect; B, oral aspect.

Apical system large, periproct off-center due to suranal plate. Tubercles crenulate. Spines white, shiny, long and

slender, sometimes thorny. Interambulacral plates few, each with single, large, primary tubercle. Ambulacral plates

simple except near the peristome where they are compounded in two's. Genus Salenocidaris (Fig. 18) 12

18.-Sa/enocidaris (aboral

aspect).

II (4) Periproct central. Tubercles noncrenulale. Spines smooth. Ambulacra with 3 or more pore-pairs per compound

plate ' 13

12 (II) Test white, periproct purple. Spines on periproct short, enlarged distally, sometimes almost globular (Fig. 19). Test

to 12 mm diameter, spines 30-45 mm length Salenocidaris varispina

Figure 19.-Periproctal spine ofSa/enacidaris varispina.

11
12 (1 J) Whitish all over. Spines on periproct tapered distally (Fig. 20). Test to 16 mm diameter, spines 40-60 mm length

.......................................................................................Salenocidaris profundi

Figure 20.-Periproctal spine ofSa/enocidaris profundi .

13 (11) Echinoid type compound ambulacral plates with 5-7 pore-pairs per plate (Fig. 21 A). Test height 50-65% diameter,

arched. Test covered with spines and tubercles, no naked areas. Primary tubercles and spines forming distinct vertical series but not much larger than secondaries. Color green with different degrees of red-brown. Spmes may be

whitish. Test up to 100 mm diameter, 60 mm usual maximum (Fig. 21 B) Strongylocentrotus droebachiensis

13 (1/) Ambulacral plates compounded with 3 pore-pairs per plate (either arbacioid or echinoid type) 14

A

Figure 21.-Strongy/ocentrotus droebachiensis. A, echinoid type compound ambulacral plates; B, oral aspect.

8

14 (13) Periproct covered by 4 triangular plates (Fig. 22A) simulating anal pyramid. Arbacioid type compound ambulacral

plates (Fig. 22B). Mid-interambulacral areas on upper surface naked. Secondary spines absent or poorly developed.

Family Arbaciidae 15

8

Figure 22.-Arbaciidae features. A, apical system; B, arbacioid type compound ambulacral plates.

12
14 (13) No triangular periproctal plates, mid-interambulacral areas tuberculated. Echinoid type compound ambulacral

plates 16

15 (14) Test hemispherical to subconical. Spines circular in cross section. Secondary spines absent. Test and spines uniform

brown, deep red, purple, or black. Test to 56 mm diameter (Fig. 23) Arbacia punctulata

Figure 23.-Arbacia punetulala (aboral

aspect).

15 (14) Test slightly pentagonal, hemispherical to subconical. Primary spines to 100 mm, triangular in cross section, shiny

bright red above, white below. Aboral spines curving up slightly, ends with white shiny covering. Secondary spines

present. Naked aboral interambulacral areas with blue-purple markings, bordered laterally by red lines. Test to 50

mm diameter (Fig. 24) Coelopleurusjloridanus

Figure 24.~oelopleurus floridanus

(aboral aspect).

13
16 (/4) Test rarely exceeding 13 mm diameter. Depressions around primary tubercles, causing them to appear to be on

raised mounds. Test surface densely covered with short spines. Periproct covered by single large suranal plate. Peristome naked except for 5 pairs of buccal plates. Color reddish or greenish with white patches Genocidaris maculata

16 l14) Tubercles not surrounded by depressions. Periproct covered by numerous small plates 17

17 (16) Aboral primary ambulacral tubercles irregular, occurring on every plate in some columns, on every 2nd, 3rd, or 4th

plate in other columns (Fig. 25). Tridentate pedicellariae with wide valves. Aboral side reddish. Test diameter to

100 mm, height 55% of diameter Echinus wallisi

Figure 2S.-Echinus wallisi (partial

aboral aspect).

17 (16) Aboral primary tubercle on every ambulacral plate 18

18 (17) Test low (50-60% diameter), hemispherical or conical. Primary ambulacral tubercles of very unequal size in a vertical column, or if size decreases regularly towards apical system then other column of same ambulacrum not of correspondingly equal size. Tridentate pedicellariae with long (3-5 mm), slender valves. No ocular plates in contact

with periproct. Color white. Test diameter to 51 mm (Fig. 26) Echinus affinis

Figure 26.-Echinus affinis (partial

aboral aspect).

18 (17) Primary ambulacral tubercles forming regularly sized series 19

19 (18) Test globular. height 100% of diameter. Tubercles very small. Color of test dark green, pore zones and triangular

patch below each primary tubercle white, giving distinct zigzag appearance. Test to 100 mm diameter (Fig. 27) .. Echinus gracilis

Figure 27.-Echinus gracilis (lateral

aspect).

14
19 (18) Test only lightly tinted or white 20

20 (19) Test almost globular, height 75% of diameter. Sutures and tube-feet pores sunken. Regions above and below primary

tubercles slightly raised, giving appearance of tubercles occurring on vertical ridges. Primary and secondary spines

short and robust. Secondaries few. Test white, spines reddish. Test to 100 mm diameter (Fig. 28) Echinus tylodes

Figure 28.-Echinus tylodes (lateral

aspect).

20 (19) Test low, conical or flattened above. Pores not sunken. Periproct often slightly raised. Primary spines characteristically long and slender. Primary ambulacral tubercles and spines equally sized in each column at the margin, reducing abruptly in size on upper surface. One or two ocular plates in contact with periproct. Color pink, fading to

white after preservation. Test to 86 mm diameter (Fig. 29) Echinus alexandri

Figure 29.-Echinus alexandri (aboral

aspect).

21 (2) Five lunules. Periproct on oral surface between mouth and posterior lunule. Genital pores 4 (occasionally morc on

aberrant genital plates). Food grooves on lower side bifurcate close to peristome. Color brown to green. Test to

about 120 mm length (Fig. 30) Mellita quinquiesperforata

A

()

Figure 30.-Mellita quinquiesper!orata. A, aboral aspect; B, oral aspect.

15
21 (2) No lunules. Periproct on posterior margin. Genital pores 4. Food grooves 5, straight, trifurcating towards margin.

Lower side usually flat. Spines very short aborally, longest around peristome. Color red to brown, tube-feet and

accessory tube-feet red (Turns almost black above and greenish below in Formalin). Test to 100 mm length (Fig.

31) Echinarachnius parma

Figure 31.-Echinarachnius parma

(aboral aspect).

22 (3) Aboral ambulacra simple. No petals. Labrum followed by single sternal plate (meridosternous, Fig. 4). Apical system longitudinally elongate or disjunct 23

22 (3) One or more ambulacra on upper surface modified into petals. Labrum followed by paired sternal plates (amphisternous, Fig. 4). Apical system compact, central 25

23 (22) Test bottle-shaped (Fig. 32). Subanal snout prominent, with subanal fasciole. Color purple. Length to 110 mm,

usually under 50 mm Pourtalesia miranda

a 0

O' '

QI 0 :'.

o'

Figure 32.-Pourtatesia miranda. A, aboral aspect; B, lateral aspect.

23 (22) Test ovoid. . . . . . . . . . .. . 24

24 (23) Lower surface flattened. Periproct submarginal, visible from below. No fascioles. Color pale brown. Length to 30

mm (Fig. 33) Urechinus naresianus

Figure 33.-Urechinus

(aboral aspect).

16
24 (23) Lower posterior surface bulging, forming subanal snout, with subanal fasciole. Periproct visible from above only.

Color light gray (in alcohol). Length to 20 mm (Fig. 34) , , , . , . , , .. , ' , ' .. , , . . .. ., Plexechinus hirsutus

Figur~ 34.-Plexechinus hirsutus. A, "boral aspect; B, lateral aspect.

2S (22) Internal fasciole present, also subanal fasciole, with anal branches. No peripetalous fasciole. Test faintly heartshaped with shallow anterior notch. Periproct high on posterior surface Paired petals widest proximally, tapering

distad. Color pale brown. Test to 92 mm length (Fig. 35) ,... .." , Echinocardium cordatum

----~

A c:5Z......1-:>::;;·.J~ , . ':7 /,:.1

Y · .. ' ( .. (.,/

" . './

35.-Echinocardium corda/um

(aboral aspect).

25 (22) No interr.al fasciole, Peripetalous fasciole present , ', , ,.. . .. 26

26 (25) Only a peripetalous fasciole present , , . , , , .. , . ............................. 27

26 (25) Peripetalous fasciole present in addition to latero-anal or subanal fasciole , , .. , , .29

27 (26) Test globular, fragile, highest at posterior end. Upper surface flattened, sloping forward. Paired ambulacra strongly

petaloid, petals small. Fasciole well developed. Color brown with fasciole dark when intact (denuded in picture).

Length to 55 mm, usually much less (Fig. 36) , , Hemiaster expergitus

Figure 36.-HemiastBr expergitus

(aboral aspect).

17
27 (26) Test ovoid or elongate. Frontal ambulacrum strongly petaloid, paired petals rudimentary 28

28 (27) Test elongate, almost cylindrical. Length up to 3.5 times greater than width. Frontal ambulacrum not sunken. Fasciole restricted to frontal half of test. Peristome flush on lower surface. Periproct above ambitus, visible from above.

Color brown. Length to 40 mm (Fig. 37) Aeropsis rostrata

Figure 37.-Aeropsis rostrata (aboral

aspect).

28 (27) Test low, width 50-75% of length. Frontal ambulacrum large, sunken, occupying almost half of upper surface. Frontal margin notched. Peristome vertical on front end. Periproct below margin. Color gray (preserved). Length to 30

mm (Fig. 38) Acestebellidifera

Figure 38.-Aceste bellidifera (aboral

aspect).

29 (26) Subanal fasciole present, no latero-anal fasciole. Genital pores 4 in adults 30

29 (26) No subanal fasciole, latero-anal fasciole present. Genital pores 2 or 3 in adults 31

30 (29) Peripetalous fasciole single (Fig. 39A). Posterior petals confluent proximally. divergent along distal half. Test

elongate oval with shallow frontal notch. Subanal fasciole kidney-shaped (Fig. 39B) sometimes with anal branches.

No enlarged tubercles on upper surface. Color light brown to greenish. May exceed 85 'llm in length ..... Brissopsis mediterranea

A

Figure 39.-Brissopsis mediterranea. A. aboral aspect; B, posterior aspecl.

18
30 (29) Peripetalous fasciole doubled or tripled in places. Posterior petals divergent along entire length. Frontal ambulacrum

flush with test within fasciole, sunken outside forming deep anterior notch. Enlarged tubercles on upper surface.

Petals widest midway along length. Color pale purple. Reaches 130 mm length (Fig. 40) Plethotaenia spatangoides

Figure 40.-Plelholaenia spalangoides

(aboral aspect).

31 (29) Genital pores 3 in adults (Fig. 4IA). Lower surface with 2 lateral bumps on posterior edge (Fig. 4IB). Frontal petal

large, sunken, forming deep anterior notch. Posterior paired petals 1/3 length of anterior petals. Vertical posterior

margin little higher than anterior margin. Highest point of test within peripetalous fasciole. Color brown, greenish,

or purplish. fasciole may be dark. Reaches 90 mm length Brisasterfragilis

A B

Figure 41.-Brisaslerfragilis. A, aboral aspect; B, posterior

aspect.

'31 (29) Genital pores 2 in adults. Lower surface with single central bump at posterior edge. Similar to B. fragilis in aboral

aspect. Test high, highest point at posterior end. Upper surface sloping to anterior margin, postt-cior edge vertical.

Test white to brown, fascioles purple or black. Reaches 75 mm length (Fig. 42) Schizaster orbignyanus

Figure 42.-Schizasler orbignyanus

(posterior aspect).

19
ANNOTATED SYSTEMATIC LIST

Since the completion of Mortensen's Monograph of the Echinoida (1928-51). the nomenclature of the Echinoidea has been

quite stable. The monograph includes complete synonymies and

bibliographies for all but a few recently described species. Classification follows that of Moore (1966).

Class ECHINOIDEA

Order Cidaroida

FAMILY CIDARIDAE

These are the pencil urchin.s (often incorrectly called slate pencil urchins which belong in the genus Heterocentrotus, Echinometridae, from the Pacific). Cidaroids are primitive echinoids and

are believed by many to have given rise to all post-Paleozoic

echinoids. The group occurs in all seas and is perhaps most successful at present in the Antarctic.

Cidaris abyssicola (A. Agassiz 1869). It occurs off the east coast

of the United States from Georges Bank (36-390 m) south to

the Florida Straits. It also occurs off Yucatan and the Lesser

Antilles. Bathymetric distribution is 36-800 m.

It probably occurs on firm substrata ingesting forams and

other small invertebrates from the sediment surface. Small

genital pores suggest it may have a pelagic larva. Worm tubes,

pelecypods, and barnacles may be attached to the spines.

Stereocidaris ingolfiana Mortensen 1903. Although rare, this

species has been taken widely over the North Atlantic in the

Denmark Strait, off Georgia, in the West Indies, and from the

North Sea to the Cape Verdes. It is yet to be taken on the New

England slope. Bathymetric distribution is 300-1,745 m.

Large genital pores suggest direct development, but life

history is otherwise unknown.

Order Echinothurioida

FAMILY ECHINOTHURIIDAE

The echinothurioid urchins are deep-water urchins with inflated but highly flexible tests that collapse to a disc when taken

from the water. The plates are overlapping and have membranous

connections rather than the rigid sutures of most echinoids. They

live on soft bottoms upon which they support themselves by long,

delicate, oral primary spines that are either hoofed or club-shaped.

They are capable of surprisingly rapid movement. The tubercles

are perforate and noncrenulate. The ambulacral plates are compounded in the diadematoid fashion but sometimes with such a

high degree of modification that it is termed the echinothurioid

type. As in cidaroids the ambulacral plates continue across the

peristome. The secondary spines are tipped with poison glands

and live specimens should never be handled with naked hands.

Some authorities believe that this group is a survivor from the

Paleozoic era, others that it is only a peculiar offshoot of the

diadematoids. The fragile, flexible nature of the test and the deepwater epifaunal habitat result in poor representation in the fossil

record.

Araeosoma fenestratum (Wyville-Thomson 1872). This species

apparently occurs all over the North Atlantic from the Denmark

Straits to Yucatan and Barbados and off Ireland and Portugal. It

has not yet been taken north of Cape Hatteras off the eastern

United States. Bathymetric distribution is 160-1,180 m.

20

Gut contents include bottom sediments and a variety of plant

fragments.

Hygrosoma petersi (A. Agassiz 1880). This species has been taken

from off Sable Island and south to off Barbados, in the Gulf of

Mexico, off Ireland, the Azores, Senegal, the Bay of Biscay, and

South Africa. Bathymetric distribution is 200-3,700 m

(1,000-2, 100 m off the northeastern United States).

The purple color is unchanged by preservation. The gut has

been found to contain mud and fragments of Sargassum and

Thalassia (Pawson 1982). The eggs are large and yolky, probably indicating direct development. Parasitic copepods

commonly form galls on the inner surface of the test. This

epibenthic species is very active and capable of relatively fast

movements (Pawson 1982).

Phormosoma placenta Wyville-Thomson 1872. This species

occurs all over the North Atlantic from the Davis Strait and Iceland south to the West Indies and the Gulf of Guinea. Subspecies occur in the North Atlantic (placenta), Caribbean

(sigsbei), and off southwestern Africa (africana). Bathymetric

distribution is 50-3,700 m, but it is very rare in depths

shallower than 500 m (1,300-2,700 m off the northeastern

United States), and the specimen from 50 m has questionable

data.

The test is more rigid than that of most echinothurioids.

Observations on live animals by scientists in the deep-diving

submarine Alvin show that this species has large sacs enclosing

spines on the upper surface. These are always lost in specimens

collected in dredges or trawls. The species is gregarious, occurring sporadically in large groups on the sea floor. It is frequently

taken in deep trawls. The eggs are large (I mm in diameter) and

yolky, implying direct development. The gut may contain

mucus-bound pellets of mud, 1-3 mm in diameter (Pawson

1982).

Order Diadematoida

FAMILY ASPIDODIADEMATIDAE

This small family contains tropical deep-water urchins with

small (up to 30 mm) globular tests and very long (up to 150 mm),

slender spines that curve towards the substratum. The oral spines

widen at the tip. This provides a footing that enables the urchins

to live on soft muddy substrates with the test held well off the

bottom.

Plesiodiadema antillarum (A. Agassiz 1880). This species occurs

from off New Jersey (1,800 m) and Bermuda south to central

Brazil in the western Atlantic and from the Canaries to southwest Africa in the eastern Atlantic. Bathymetric distribution is

580-3,700 m.

This species ingests bottom mud and detritus. Development

is unknown but the eggs are small (0.1 mm or less) and it is probably indirect.

Order Pedinoida

FAMILY PEDINIDAE

Caenopedina cubensis A. Agassiz 1869. This rare species occurs

south of Cape Cod (360-400 m) to the West Indies and off the

Azores and Canaries. Bathymetric distribution is 250-1,200 m.

The gut contains bottom detritus, but the life history is otherwise unknown.
Order Salenioida

FAMILY SALENIIDAE

The saleniids are remarkably like the more primitive cidaroids,

but are easily distinguished by their imperforate primary tubercles, lack of ambulacral plates on the peristome, and an off-center

periproct which is displaced by a large suranal plate. The group is

mostly fossil with only two extant genera with species mostly

restricted to the tropics. The habitat and life history are believed

to be similar to the aspidodiadematids (above).

Salen'ocidaris varispina A. Agassiz 1869. It has been taken just

south of Cape Cod (900 m) and occurs south to southern Brazil

in the western Atlantic. It is known from the Bay of Biscay to

southwest Africa in the eastern Atlantic. Bathymetric distribution is 250-3,000 m.

Intestines contain poorly defined mud balls (Pawson 1982).

Salenocidaris profundi (Duncan 1877). This species has not yet

been taken in the study area but could have been confused with

S. varispina. It is presently known from Bermuda, off South

Carolina (1,920 m), and throughout the Greater and Lesser Antilles in the western Atlantic. In the eastern Atlantic it is known

from Iceland to Tristan da Cunha. Bathymetric distribution is

220-3,700 m.

Order Arbacioida

FAMILY ARBACIIDAE

The shallow- water representatives of this family occur in

tropical and temperate American seas with one species extending

to the eastern Atlantic.

Coelopleurus floridanus A. Agassiz 1872. This species occurs from

Surinam, through the West Indies, and up the U.S. east coast to

Cape Hatteras. A specimen has reportedly been taken 150 km

south of No Mans Land (southwest of Martha's Vineyard) in

190 m (Harvey 1956). Bathymetric distribution is 65-2,380 m,

but it is rare below 500 m.

This is one of the most beautiful urchins in the North Atlantic. The colors of red, white, and blue fade only slightly with

preservation. It lives on sandy bottoms and the gut contains

sand, fragments of bryozoans, octocoral spicules, and worm

tubes (Lewis 1963).

Arbacia punctulata (Lamarck 1816). This species occurs from the

south side of Cape Cod to the Bahamas and northern Cuba and

throughout the Gulf of Mexico. A southern population occurs

from Panama to Surinam, but it is absent from Hispaniola,

Jamaica, the south coast of Cuba, and the Lesser Antilles north

of Barbados. Bathymetric distribution is 0-225 m, but the

species generally occurs in < 50 m.

This is a common sea urchin of the warmer waters of the east

coast of North America. It is easily recognized by conspicuous

naked median areas in the aboral interambulacra and an anal

cone composed of four triangular plates. This species has been

used so extensively in embryological studies that it has been the

subject of a book (Harvey 1956). Most of the information

below comes from this source.

The spines vary from short and stout to slender and pointed

depending on degree of exposure to wave action. In many echinoid species, specimens from areas subjected to wave turbulence have short, stout spines and specimens from calm water

have longer, more slender spines. The oral spines tend to be

spatulate distally, an adaptation for locomotion. When re21

moved, spines take about 2 mo to regenerate.

The color is variable. In the Massachusetts region specimens

can be reddish, purplish, brownish, and sometimes almost

black. Further south, very pale specimens have been taken. The

color is known to change according to lighting conditions.

This species is omnivorous, although it is primarily an algal

feeder. It prefers hard substrata and is gregarious, occurring in

widely separated beds. In each bed, urchins tend to be of

approximately the same age. Beds die out occasionally and may

become reestablished later. In the Woods Hole region, A. punctulata is obtained by dredging in 6-30 m, but numbers have

declined through the century as a result of over-collecting.

Throughout its range, A. punctulata is subjected to temperatures

ranging approximately from 2° to 30°C.

Arbacia punetulata spawns from June through August at

Woods Hole, for longer periods further south, and generally

year-round with a peak in fall off western Florida (Serafy

1979). Development is by an echinopluteus larva, which takes

3-4 mo through metamorphosis in the laboratory (23°C). The

growth rate in nature is unknown for New England. Serafy

(1979) found that urchins which had metamorphosed off

western Florida in April reached a test diameter of 25 mm by

the following November.

Order Temnopleuroida

FAMILY TEMNOPLEURIDAE

This family is richly represented in the Indo-west Pacific but

has only three species in the North Atlantic. Members have a high

degree of surface sculpture (pits, grooves, depressions, ridges,

naked areas) on the test and the tubercles are imperforate. The

ambulacral plates are compounded in the echinoid fashion. There

are three pore-pairs to each compound plate. Many of the Pacific

species are remarkably colorful.

Genocidaris maculata A. Agassiz 1869. In the western Atlantic

this species occurs from south of Cape Cod (210m) to northern

Brazil. In the eastern Atlantic it occurs from the Azores and the

Mediterranean Sea to off the Congo. Bathymetric distribution is

12-420 m.

This is a very small species rarely exceeding 13 mm in

diameter with genital pores developing at 3-5 mm (Serafy

1979). It appears to Iive on sand substrates and ingests sand and

small benthic animals (forams, snails, bryozoa, etc.). The eggs

are very small (0.05 mm), suggesting a pelagic larva.

Order Echinoida

FAMILY ECHINIDAE

The genus Echinus has 18 species of which 13 occur in the

Atlantic. Ten of these are restricted to the North Atlantic, which is

believed to be the area of origin of the genus.

Echinus affinus Mortensen 1903. This is essentially a deep-water

species ranging from Iceland south to Georgia and the Azores.

Bathymetric distribution is 130-5,300 m, but it is rare in depths

< 1,000 m. It has been taken in 830-2,700 m off the northeastern United States.

Scientists in the submarine Alvin have noted that this species

is gregarious and occurs in large sporadic patches on the ocean

floor. Gut contents include bottom sediment and forams.

Echinus alexandri Danielssen and Koren 1883. This is a deepwater species ranging from northern Norway and Iceland south
to off Cape Hatteras in the western Atlantic and the Azores in

the eastern Atlantic. Bathymetric distribution is 365-3,120 m

(830-2,700 m off the northeastern United States).

Life history is probably similar to E. affinis and gut contents

include mud and foraminifera.

Echinus gracilis A. Agassiz 1869. This species ranges from south

of Cape Cod (130-250 m) to northern Cuba, off Puerto Rico,

Yucatan, and Venezuela. Bathymetric distribution is 70-450 m.

The characteristic zigzag color pattern of this species is

altered only slightly by preservation and makes it immediately

recognizable. It apparently prefers firm bottoms. The gut has

been found to contain coarse bottom material, shell fragments,

bryozoa, and sponges. Eggs are small.

Echinus tylodes H. L. Clark 1912. This species occurs off the U.S.

east coast from off Cape Cod (270 m) to the Florida Straits.

Bathymetric distribution is 270-810 m.

This species is easily recognized by its pink, stout spines and

rather bare test. The gut contains small shells and hydroids.

Eggs are small.

Echinus wallisi A. Agassiz 1880. This rare species has been taken

off Georges Bank (960 m), southeast of Cape Cod (560 m), off

Georgia and northern Florida. Bathymetric distribution is

460-2,600 m.

FAMILY STRONGYLOCENTROTIDAE

This family is circumarctic to circumboreal in distribution with

S. droebachiensis (and possibly S. pallidus) being the only species

in the North Atlantic.

Strongylocentrotus droebachiensis (0. Fr. MUller 1776). This

species has a circumpolar distribution. It has been taken as far

north as northern Greenland, Spitsbergen, and the Siberian Sea.

It occurs intertidally north of Cape Cod but only subtidally

south of Cape Cod to the mouth of the Chesapeake Bay. In the

eastern Atlantic it occurs south into the North Sea (lat. 52 ON).

In the Pacific it occurs south to Kamchatka (lat. 54 ON) and

Puget Sound (Iat. 48°N). It has also been taken in Hudson Bay.

Bathymetric distribution is 0-1,150 m, although it is most common in < 50 m and is rare below 300 m.

As with Arbacia punctulata, those specimens subject to wave

action tend to have shorter, stouter spines. The color of the test

and spines is green, but on some specimens the spines (and

more rarely the test) may be whitish. Red-brown pigment

granules occur in the epidermis of the test and, if concentrated,

may make the test appear red-brown, especially on the apical

system and down the vertical sutures. These spots turn dark purple in Formalin. The concentration of these pigment granules is

related to the consumption of red algae.

This species is mostly a shallow-water coastal species. It is

found in large numbers on rocky seashores, but also occurs on

sand and mixed bottom types where it tends to be more evenly

spaced and more dispersed. It is omnivorous, but mostly herbivorous, preferring the brown kelp Laminaria sp. over other

macroalgae from the northeastern United States. It is known to

damage kelp beds when its concentrations are large (Mann

1977, 1982). Large numbers will aggregate to and pile up on

any loose pieces of kelp on the bottom. These vigorous scavenging habits have earned it the title of "marine rodent." Adults

will eat smaller specimens in aquaria.

In the New England area spawning occurs from January

through April. The gonads are largest in November to April and

are edible, but not especially palatable. Efforts to develop a roe

22

fishery have met with failure. A starved urchin can live many

months by metabolizing its gonads. Development is via an echinopluteus larva. Swan (1961) found that in southern Maine, S.

droebachiensis grows to about 10 mm in 6 mo, 25 mm in 1.5 yr,

40 mm in 2.5 yr, 50 mm in 3.5 yr, and 55 mm in 4.5 yr.

Strongylocentrotus droebachiensis may be found in estuaries

where the salinity does not drop below 29°/00. Throughout its

range, temperatures between -1.8 ° and 21°C are encountered.

Under adverse conditions they may autotomize their spines;

these take about 1 mo to regenerate on juveniles and 2-3 mo on

adults. The larger urchins migrate from the tidal zone to deeper

water for the winter and return in the spring. These migrations

take place in a matter of 2-3 d and in Maine, they occur in midDecember and mid-May.

There is evidence based on studies involving sperm agglutination that another species, S. pallidus, may also occur off the

northeastern United States. Jensen (1974) indicated that S.

pallidus has more pore-pairs per arc (6-7 rather than 5-6 for S.

droebachiensis) and globiferous pedicellariae with poison

glands swollen and head spherical (compared with globiferous

pedicellariae with muscular neck and head ovoid for S. droebachiensis). These characters are quite variable and at present

there is no clear morphological distinction between the two

species (Swan 1962).

Order Clypeasteroida

FAMILY ECHINARACHINIIDAE

This family of sand dollars has a circumarctic to circumboreal

distribution and appears to have a single surviving species.

Echinarachnius parma (Lamarck 1816). In the North Atlantic E.

parma occurs from Labrador to off Cape Hatteras. In the Pacific

it occurs from Alaska to Vancouver Island and along the Aleutians to Kamchatka and northern Japan. Bathymetric distribution is 0-1,625 m, but specimens are uncommon below 100 m.

Echinarachnius parma can be found in large numbers from

just below low water to about 100 m. It is common on substrates of coarse to fine skewed medium sands (0.8-2.2 <1» with

low silt-clay values «5%) (Serafy, unpubl. data). Nourishment

is derived from organics within ingested sand and detritus

which may settle on the test and be carried to the mouth by

ciliary currents. It occurs in beds of varying densities,

sometimes as high as 400/m2 • Time-lapse photography off

Massachusetts has shown that shallow-water populations bury

themselves during the day and in winter may remain buried at

night too. Throughout its range E. parma could be expected to

encounter temperatures of -1.8 ° to 28°C. Spawning time can

span June through November, with a peak in late summer to

fall. The echinopluteus larva can be raised through metamorphosis without difficulty if fed on phytoflagellates (e.g.,

Dunaliella). Specimens under 10 mm TL concentrate the heavy

mineral magnetite (Fe 30 4) in their intestinal diverticula. This is

believed to enable small specimens to remain on the bottom

during high current activity. Small specimens are eaten by cod

and haddock.

FAMILY MELLITIDAE

Mellita quinquiesperjorata (Leske 1778). This species occurs from

south of Cape Cod along the U.S. east coast, throughout the

Gulf of Mexico and Caribbean Sea to Sao Paulo, Brazil. Bathymetric distribution is 0-180 m, but it is most common in < 30

m.
It lives most commonly on sand and silty-sand substrata of

estuaries and inshore environments.

In Florida the larval life-span is 7 to 9 d. Specimens off

western Florida reach a size of 50-75 mm test length after I yr

and 80-100 mm after 2 yr. Spawning occurs from February to

April off western Florida (Serafy 1979).

Order Holasteroida

FAMILY URECHINIDAE

Irregular echinoids with the labrum followed by a single sternal

plate forming the meridosternous plastron (Fig. 4C). The first

plate in each of the paired interambulacra also followed by a

single plate. There are no petals, the ambulacra are essentially

similar to the interambulacra. The apical system is longitudinally

disjunct, with anterior and posterior portions. This is a deep-water

family with representatives rarely taken in < 500-1,000 m.

Urechinus naresianus A. Agassiz 1879. This species is apparently

distributed throughout the Atlantic from the Davis Strait to the

subantarctic region. Bathymetric distribution is 770-5,200 m

(2,300-3,100 m off the northeastern United States).

Life history is unknown. The lack of fascioles or petals and

the coarse spination suggest that this species is a shallow

burrower.

Plexechinus hirsutus Mortensen 1905. This species has been taken

sporadically from around Iceland t9 the West Indies. Bathymetric distribution is 750-3,060 m (3,060 m off the northeastern United States).

FAMILY POURTALESIIDAE

These are meridosternous irregular echinoids with extremely

modified test shapes and they are known as bottle urchins. The

test is basically oval in shape with the anterior end truncated with

a deep groove extending from the anterior ambitus to the vertical

mouth on the ventral side. There is a long subanal snout and

subanal fasciole at the posterior end. These deep-water urchins are

very fragile and are rarely taken inta<:t.

Pourtalesia miranda A. Agassiz 1869. This species has been taken

in the Atlantic from the Davis Strait, around Iceland, and northeast of the British Isles, south through the Caribbean and into

the South Atlantic. Bathymetric distribution is 450-5,850 m

(1,100-2,600 m off the northeastern United States).

Pourtalesia is instantly recognized by its peculiar shape and

purple color. It buries itself in soft mud and feeds on bottom

sediments. Specimens of up to 50 mm in length have been

taken, but some Caribbean fragments, recently recovered, indicate that they may reach a size of 110 mm. This means that

most of the generic classification has been made using juveniles

or small adults. There was already some question as to whether

one or two species of Pourtalesia occur in the North Atlantic,

and the absence of adult material leaves the matter unresolved

at present. The northern form was described as P. wandeli

Mortensen 1907, while the tropical form is P. miranda.

Order Spatangoida

FAMILY HEMIASTERIDAE

Spatangoids with the labrum followed by two sternal plates

(amphisternous) forming the plastron (Fig. 4B). Paired petals are

small but well developed and are surrounded by a prominent peri23

petalous fasciole. No other fascioles are present.

Hemiaster expergitus Loven 1874. This deep-water species has

been taken from the Davis Strait south through the Caribbean

to Brazil in the western Atlantic and from Iceland to southwest

Africa in the eastern Atlantic. A subspecies occurs throughout

the northern Pacific and has been taken off New Zealand.

Bathymetric distribution is 380-4,833 m (1,102-4,833 m off

the northeastern United States).

The well-developed fasciole, petals, and frontal ambulacrum

suggest a deep burrowing existence.

FAMILY AEROPSIDAE

Amphisternous spatangoids with a peripetalous fasciole, welldeveloped frontal petal with large tube-feet, but only rudimentary

paired petals. This is a small deep-water family with only two

genera. The large frontal ambulacrum, tube-feet, and fasciole suggest a burrowing existence. Life history is otherwise unknown.

Aeropsis rostrata (Wyville-Thomson 1876). This species occurs in

the Davis Strait, off the eastern United States, south to Cape

Hatteras and Bermuda, and off Uruguay in the western Atlantic.

It has been collected in the Bay of Biscay, off Portugal, and off

Sierra Leone in the eastern Atlantic. Bathymetric distribution is

1,100-4,897 m (1,100-2,900 m off the northeastern United

States).

Aceste bellidifera Wyville-Thomson 1877. This species has been

taken in the western Atlantic from south of Cape Cod through

the Gulf of Mexico, the Caribbean, to off southern South

America. In the eastern Atlantic it is known from the Canaries

and off Senegal. Bathymetric distribution is 550-5,220 m

(1,100-3,000 m off the northeastern United States).

FAMILY SCHIZASTERIDAE

Amp.histernous spatangoids with a peripetalous fasciole and a

latero-anal fasciole.

Schizaster orbignyanus A. Agassiz 1880. This species occurs from

south of Cape Cod (110-230 m) through the Caribbean and

Gulf of Mexico to Surinam. Bathymetric distribution is 26-500

m.

It is known from bottoms of crushed shell, algal sand, and

mud. Life history is otherwise unknown.

Brisaster fragilis (Duben and Koren 1844). This species ranges

from the Barents Sea, off the coast of Norway, off Iceland, in

the Davis Strait, and south along the east coast of North

America to Georgia. Bathymetric distribution is 14-1,700 m

(100-850 m off the northeastern United States).

It occurs on muddy bottoms, but life history is otherwise

unknown.

FAMILY BRISSIDAE

Amphisternous spatangoids with a peripetalous fasciole and a

subanal fasciole.

Brissopsis mediterranea Mortensen 1913. This species ranges from

Newfoundland to the Florida Straits, off Colombia and Venezuela, in the Mediterranean Sea, and off the west coast of Africa

to the Gulf of Guinea. Bathymetric distribution is 37-3,200 m
(160-2,886 m off the northeastern United States).

The life history is unknown, but is probably similar to that of

B. alta and B. atlantica which have been studied in detail by

Chesher (1968).

FAMILY SPATANGIDAE

Amphisternous spatangoids with only a subanal fasciole (except Plethotaenia which also has a peripetalous fasciole).

Plethotaenia spatangoides (A. Agassiz 1883). This species occurs

from Cape Cod south through the Gulf of Mexico and Caribbean. Bathymetric distribution is 150-619 m.

The gut contains mud, forams, pteropods, small bivalves, and

gastropods and it apparently lives only partially buried

(Chesher 1968).

FAMILY LOVENIIDAE

Amphisternous spatangoids with an internal fasciole.

SELECTED BIBLIOGRAPHY

Further infonnation concerning echinoids may be obtained by consulting

Mortensen (1927), Nichols (1966), Millott (1967), and Clark (1968). New

Englanders may find Coe (1912) and Harvey (1956) most useful. Hyman (1955),

Boolootian (1966), Moore (1966), and Smith (1984) contain data of a more

technical nature and are more useful to echinodenn specialists. Harvey (1956) is indispensable to the echinoid embryologist. A vast amount of laxonomic infonnation

and complete bibliographies for all species may be found in Mortensen (1928-51).

BOOLOOTlAN, R. A. (editor).

1966. Physiology of Echinodennata. Intersci. Publ., N.Y., 822 p.

BUCHANAN, J. B.

1966. The biology of Echinocardium cordatum [Echinodermata: Spatangoidea] from different habitats. J. Mar. BioI. Assoc. U.K. 46:97-114.

CHESHER, R. H.

1968 The systemalics of sympalric species in West Indian spatangoids.

Stud Trop. Oceanogr. (Miami) 7, 168 p.

CLARK,A.M.

1968. Starfishes and their relatives. 2d ed. Trust. Br. Mus. (Nat. Hist.),

Lond., Publ. No.377, I 18 p.

COCANOUR, B. fl..

1969. Growth and reproduction of the sand dollar, Echinarachnius parma

Echinodermala: Echinoidea). Ph.D. Thesis, Univ. Maine at Orono, 96 p.

COE, W. R.

1912. Echinodenns of Conneclicut. Conn. Geol. Nat. Hist. Surv., Bull. 19,

152 p. (Reprinted in original form in 1972 as "Starfishes, serpentstars, sea

urchins and sea cucumbers of the northeast," Dover Publ., N.Y.)

HARVEY, E. B.

1956. The American Arbacia and other sea urchins. Princeton Univ.,

Princeton, N.J., 298 p.

HYMAN, L. H.

1955. The invertebrates: Echinodennata. Vol 4. McGraw-Hill, N.Y., 763 p.

JENSEN, M.

1974. The Strongylocentrotidae (Echinoidea), a morphologic and systematic

study. Sarsia 57:113-148.

KIER, P. M.

1982. Rapid evolution in echinoids. Palaeontology 25:1-9.

24

Echinocardium cordatum (Pennanl 1777). This species is cosmopolitan. It is rare in the western Atlantic, but is known from off

New Jersey to the Caribbean Sea. Bathymetric distribution is

0-230 m.

This species occurs in shallow water in Europe, and it has

been studied extensively (Mortensen 195 I; Nichols 1962;

Buchanan 1966). The life history and development of this

species are probably typical of most spatangoids. It lives in a

burrow about 15 to 20 cm deep. A respiratory tube extends to

the surface of the sea floor and is maintained by the large tubefeet of the frontal ambulacrum. A similar but blind canal extends posterior from the subanal fasciole and is maintained by

the large tube-feet originating within the fasciole. Th'e surfaces

of the burrow and tunnels have a lining of mucus. The ciliated

spines of the fasciole create water currents which cause water to

pass down the respiratory tube onto the apical system, frontal

ambulacrum, and paired petals. The water currents flow past

the respiratory tube-feet of the petals over the surface of the tesl

to the subanal fasciole which directs the water to the rear

(sanitary) canal. The water flow brings suspended detritus and

oxygen to the urchin.

LAWRENCE, J. M.

1975. On the relationships between marine plants and sea urchins.

Oceanogr. Mar. BioI. Annu. Rev. 13:213-286.

LEWIS, J. B.

1963. The food of some deep water echinoids from Barbados. Bull. Mar

Sci. Gulf Caribb. 13:360-363.

MANN, K. H.

1977. Destruction of kelp-beds by sea urchins: a cyclical phenomenon or

irreversible degradation? Helgol. wiss. Meeresunters. 30:455-467.

1982. Kelp, sea urchins and predators: a review of strong interactions in

rocky subtidal systems of eastern Canada, 1970-1980. Nether. J. Sea Res.

16:414-423.

MILLOTT, N.

1967. Echinoderm biology. Acad. Press, N.Y., 240 p.

MOORE, R. C. (editor).

1966. Treatise on invertebrate paleontology. Pt U, Vols. I and 2, Echinodermata 3. Geol. Soc. Am. and Univ. Kansas, 695 p.

MORTENSEN, T.

1927. Handbook of the echinodenns of the British Isles. Oxford Univ.,

Lond., 471 p.

1928-51. A monograph of the Echinoidea. Reitzel, Copenhagen, Vols. 1-5.

NICHOLS, D.

1962. Differential selection in populations of a heart urchin. In D. Nichols

(editor), Taxonomy and geography, p. 105-118. Systematics Assoc. (Lond.)

PubI. No.4.

1966. Echinoderms. 2d ed. Hutchinson, Lond., 200 p.

PAWSON, D. L.

1982. Deep-sea echinodenns in the Tongue of the Ocean, Bahama Islands: A

survey, using the research submersible Alvin. Aust. Mus. Mem. 16:129-

145.

SERAFY, D. K.

1979. Echinoids (Echinodennata: Echinoidea). Mem. Hourglass Cruises

5(part 3), 120 p.

SMITH, A.

1984. Echinoid palaeobiology. George Allen & Unwin, Lond., 190 p.

SWAN, E. F.

1961. Some observations on the growlh rate of sea urchins in the genus

Strongylocentrotus. BioI. Bull. (Woods Hole) 120:420-427.

1962. Evidence suggesting the existence of two species of Strongylocentrotus

(Echinoidea) in the Northwest Atlantic. Can. J. Zool. 40: 1211-1222.
SYSTEMATIC INDEX

Aceste , 4

bellidifera ' 4, 18, 18, 23

Aeropsidae . 23

Aeropsis 4

rostrata , 4, 18,18,23

Araeosoma . . . . . . . . . . . . . . . . . . . . . . .. . ,3, 4

fenestratum ' .. .4, 10,10,20

Arbacia " 3

punctulata .. , 2,3,4, 1313,21,22

Arbaciidae 4. 12,12,21

Arbacioida 21

Aspidodiadematidae , 20

Brisaster 4

fragilis 4. 1,9,19,23

Brissidae 23

Brissopsis , , 4

alta 24

atlantica 24

mediterranea 4, 18, 18.23

Caenopedina 3.4

cubensis 4,8,8,20

Cassiduloida 3

Cidaridae . 20

Cidaris 4

abyssicola 4,9,9,20

Cidaroida , 1,3,5,8,20

Clypeasteroida 3,5,22

Coelopleurus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . ...6

floridanus .4,13,13,21

Diadematoida 20

Echinarachniidae 22

Echinarachnius , . . . . . . . . . . .. . 4

parma ' .4, 16,16,22

Echinidae . .. . , 21

Echinus 3,6,21

affinis 4, 14,14,21,22

alexandri 4, 15,15.21

gracilis 4, 14,14,22

tylodes 4, 15,15,22

wallisi 4, 14,14,22

Echinocardium 4

cordatum 4, 17,17,24

Echinoida 5, 21

Echinoidea 1,6,20

Echinometridae 20

Echinothuriidae 20

Echinothurioida 1, 20

Genocidaris 4

25

maculata 4, 14,21

Hemiaster 4,7

expergitus . .4, 17,17,23

Hemia&teridae , 23

Heterocentrotus 20

Holasteroida 3,4,4,23

Holectypoida 3

Hygrosoma. .. ' 4

petersi .4, 10,11,20

Loveniidae .. , 24

Mellita

quinquiesperforata 4, 15,15,22

Mellitidae 4,22

Pedinidae 20

Pedinoida 20

Phormosoma 4

placenta 4, 10,10,20

Ptesiodiadema 4

antillarum .4,8,8,20

Plethotaenia 4, 7, 24

spatangoides .4, 19, 19, 24

Plexechinus 4,7

hirsutus .4, 17,17,23

Pourtalesia 4

miranda 4, 16,16,23

wandeli 23

Pourtalesiidae 23

Saleniidae 21

Salenioida 21

Salenocidaris .4,6, 11,11

profundi 4, 12,12,21

varispina 4, II, 11,21

Schizaster. . . . . . . . . . . . .. . 4

orbignyanus 4,19,19,23

Schizasteridae 23

Spatangidae 24

Spatangoida 3,4,4,23

Stereocidaris 4

ingolfiana 4,9,9,20

Strongylocentrotidae 22

Strongylocentrotus 3,4,6

droebachiensis 2,4, 12,12,22

pallidus 22

Temnopleuridae 21

Temnopleuroida 21

Urechinidae 23

Urechinus 4

naresianus 4, 16,16,23
ACKNOWLEDGMENTS

Preparation of the "Marine Flora and Fauna of the Northeastern United

States" is being coordinated by the following Board:

Coordinating Editor: Melbourne R. Carriker, College of Marine Studie~

University of Delaware, Lewes, DE 19958.

Editorial Advisers: Marie B. Abbott, 259 High Street, Coventry, CT

06238 (formerly Director, Gray Museum,

Marine Biological Laboratory, Woods Hole,

MAJ.

A. Ralph Cavaliere, Department of Biology,

Gettysburg College, Gettysburg, PA 17325.

Arthur G. Humes, Boston University Marine Program, Marine Biological Laboratory, Woods

Hole, MA 02543.

David L. Pawson, Department of Invertebrate

Zoology, National Museum of Natural History,

Smithsonian Institution, Washington, DC 20560.

Ruth D. Turner, Museum of Comparative Zoology,

Harvard University, Cambridge, MA 02138.

Robert T. Wilce, Department of Botany, University

of Massachusetts, Amherst, MA 01002.

In addition to establishing the format for the "Marine Flora and Fauna

of the Northeastern United States," the Board invites systematists to collaborate in the preparation of manuals, reviews manuscripts, and advises

the Scientific Editor of the National Marine Fisheries Service.

We regret to report that two of the original Editorial Advisers are no

longer with us: Wesley N. Tiffney passed away last year, and Roland L.

Wigley has retired from professional work. We would like to express our

deep thanks to both for their enthusiasm and support during the formative

stages of the "Marine Flora and Fauna of the Northeastern United States"

and for their many subsequent editorial contributions.

On the brighter side, we are pleased to report that two new systematists

(Cavaliere and Pawson) have joined the Board of Editorial Advisers, and

we look forward with much pleasure to their participation in the work of

the Board. Their names and affiliations are listed above.

Many individuals have assisted the authors of the present manual in a

variety of ways. Particularly to be mentioned are John H. Dearborn,

University of Maine, who is overseeing the echinoderm sections of the

"Marine Flora and Fauna of the Northeastern United States," and Ruth D.

Turner, Museum of Comparative Zoology, Harvard University, who

guided the authors in the early stages of the manual. David L. Pawson, National Museum of Natural History, critically read the manuscript. The fine

echinoid collections at the Museum of Comparative Zoology, Harvard

University, and the National Museum of Natural History in Washington,

DC, were used extensively in the preparation of the manual. All illustrations were drawn by F. Julian Fell.

COORDINATING EDITOR'S COMMENTS

Publication of the "Marine Flora and Fauna of the Northeastern United

States" is most timely in view of the growing universal emphasis on work

in the marine environment and the urgent need for precise and complete

identification of organisms related to this work. It is essential, if at all

possible, that organisms be identified accurately to species. Accurate

scientific names of plants and animals unlock the great quantities of

biological information stored in libraries, obviate duplication of research

already done, and often make possible prediction of attributes of

organisms that have been inadequately studied.

D. Keith Serafy began his echinoid work in 1967 as a student research

assistant at the Florida Department of Natural Resources Marine Research

Laboratory in St. Petersburg, FL. He continued his research on echinoids

at the University of Maine where he completed his M.S. and Ph.D.

degrees. He maintained his interest in echinoids while conducting several

environmental baseline studies on benthic communities while at the New

York Ocean Science Laboratory and the Virginia Institute of Marine

Science. Since 1978 he has been teaching and continuing his echinoid

research at Southampton College where he is an Associate Professor of

Biology and Marine Science.

F. Julian Fell started echinoid studies while an undergraduate student in

the late 1960's. He completed his M.S. and Ph.D. degrees at the University

of Maine. writing theses on echinoid systematics. He is presently following the precedent of Alexander Agassiz and is employed in the mining in26

dustry. As opportunity permits he is still conducting echinoderm studies

on his own.

Preparation of this manual was supported in part by a grant from the

Environmental Protection Agency to the Editorial Board of the "Marine

Flora and Fauna of the Northeastern United States." Work on the "Marine

Flora and Fauna of the Northeastern United States" by the Coordinating

Editor is supported by the College of Marine Studies, University of

Delaware.

Manuals are available from:

National Technical Information Service, U.S. Department ot' Com--

merce, 5285 Port Royal Road, Springfield, VA 22161, either as

paper copy or microfiche, for a charge.

Manuals are not copyrighted, and so may be photocopied from the

NOAA Technical Report NMFS Circulars available in most major

libraries.

The manuals so far published in the NOAA Technical Report NMFS

Circular series are listed below by author, title, circular number, and NTIS

accession number.

NOTE: The NOAA Technical Report NMFS Circular series has ceased

publication. It has been replaced by a new series titled NOAA Technical

Report NMFS. The Serafy and Fell contribution will be the first of the

manuals to be published under the new series.
Marine Flora and Fauna of the Northeastern United States:

COOK, DAVID G., and RALPH O. BRINKHURST. Annelida: Oligochaeta.

BORROR, ARTHUR C. Protozoa: Ciliophora.

MOUL, EDWIN T. Higher Plants of the Marine Fringe.

McCLOSKEY, LAWRENCE R. Pycnogonida.

MANNING, RAYMOND B. Crustacea: Stomatopoda.

WILLIAMS, AUSTIN B. Crustacea: Decapoda.

POLLOCK, LELAND W. Tardigrada.

LARSON, RONALD J. Cnidaria: Scyphozoa.

CAVALIERE, A. R. Higher Fungi: Ascomycetes, Deuteromycetes, and Basidiomycetes.

COULL, BRUCE C. Copepoda: Harpacticoida.

CUTLER, EDWARD B. Sipuncula.

PAWSON, DAVID L. Echinodermata: Holothuroidea.

HO, JU-SHEY. Copepoda: Lernaeopodidae and Sphyriidae.

HO, JU-SHEY. Copepoda: Cyclopoids Parasitic on Fishes.

CRESSEY, ROGER F. Crustacea: Branchiura.

BOVEE, EUGENE c., and THOMAS K. SAWYER. Protozoa: Sarcodina: Amoebae.

WATLING, LES. Crustacea: Cumacea.

ZULLO, VICTOR A. Arthropoda: Cirripedia.

CAIRNS, STEPHEN D. Cnidaria: Scleractinia.

TODD, RUTH, and DORIS LOW. Protozoa: Sarcodina: Benthic Foraminifera.

BUSH, LOUISE F. Turbellaria: Acoela and Nemertodermatida.

TAYLOR, RONALD M. Lichens (Ascomycetes) of the Intertidal Region.

SERAFY, D KEITH, and F. JULIAN FELL. Echinodermata: Echinoidea

Circular

No.

374

378

384

386

387

389

394

397

398

399

403

405

406

409

413

419

423

425

438

439

440

446

Tech. Rep. No. 33

NTIS NO.

COM 73 50670

COM 7350888

COM 74 50019

COM 74 50014

COM 74 50487

COM 74 51194

PB 257 987

PB 261 839

PB 268 036

PB 268 714

PB 273062

PB 274999

PB 280 040

PB 281969

PB 222 923

PB 285 538

PB 296 460

PB 297 676

PBI24520

PB 225 053

PB219387

PB 124735

*GPO 593-081 1985 27