THE RAFFLES BULLETIN OF ZOOLOGY200250(1): 95-99@National University of Singapore

ON A NEW SPECIES OF CAVERNICOLOUS NEOLIOMERA(CRUSTACEA: DECAPODA: BRACHYURA: XANTHIDAE)
FROM CHRISTMAS ISLAND AND RYUKYUS, JAPANPeterK. L. Ng
Department ofBiological Sciences,National University of Singapore,Kent Ridge,
Singapore 119260,Republic ofSingapore.Email: petemg@nus.edu.sg

ABSTRAC1: -A new species of cave-dwelling xanthid crab of the subfamily Liomerinae,
Neoliomera cerasinus,is describedfrom marine caves in ChristmasIsland (Indian Ocean)andRyukyus (Japan).The species,the largestknown in the genus,is characterisedby its very broad
carapace,entire anterolateralmargin without emarginationsor lobes, very granular carapace
and appendages,
elongate ambulatorydactyli and structureof the male first gonopod.
KEY WORDS.- Crustacea,Xanthidae, Neoliomera,ChristmasIsland, Ryukyus, newspecies.

INTRODUCTIONTAXONOMIC ACCOUNT

In early 2000, through the kindness of Ms. Lisa
Kirkendale, the author received an interesting

FAMILY XANTHIDAE MACLEAY, 1838 (SENSUGUINOT, 1978)

specimen of a cavernicolous crab from Christmas
Island in the Indian Ocean which had been obtainedby marine cave-~xplorers. The specimen proved toSUBFAMILY LIOMERINAE SAKAI, 1976
(SENSU SERENE, 1984)

belong to a new species of Neoliomera Odhner, 1925
(Xanthidae: Liomerinae). In mid-200l, the author

Neoliomera Odhner, 1925

obtained a specimen of another cavernicolous
Neoliomera from a marine cave in the Ryukyus inNeoliomera cerasinus, new species

Japan, through the kindness of Mr. Yoshihisa Fujita.
While the Ryukyu specimen is larger than theChristmas Island one and has a slightly smoothercarapace. there are no major characters that can(Figs. 1-5).:
dIfferentIate

them;

distributions,

bothMaterial examined. -Holotype-male (32.0 by 19.2 mm)(WAM), subterraneancavern,on sand,5-10 m depth, 10 m
deepanddespIte

are clearlytheIrvery

I ill.

dISjUnct

cave,

Thunder

DomeCave,Christmas

Island,conspecific.

Other -Male (39.2 by 24.1 mm) (ZRC), underwater
limestonecave,35 m depth,colI. T. Kawamoto,1 Oct.1999.

The present paper serves to describe this newspecies of cave-dwelling
Neoliomera, which isalso the largest species of the genus known thus far.
The abbreviations GlandG2 are used for themale first and second pleopods respectively.
Measurements provided, in millimeters, are of thecarapace width and length respectively. Specimens
are depositedin theWestern
AustralianMuseum (WAM), Perth, Australia; and Zoological
Reference Collection (ZRC), Raffles Museum ofBiodiversity
Research, National Universityof

Description of holotype male. -Carapace regions very
poorly defined; grooves separating gastric andbranchial regions very shallow but just discernible;
shallow but visible Y-shaped groove separating poorly
defined epigastric regions; dorsal surface covered withnumerous evenly spaced small rounded granules, thoseon median parts lower and relatively smaller;
pterygostomial, suborbital and sub-branchial regions
coveredwith
same patternofgranules.

Singapore.

Received 28 Sep 2001

into

n an 0 cean, co.11 L .rKi k endal e, 1 D ec. 1999 .

Front produced beyond orbits; bilobed, truncate
lobes separated by shallow but distinct cleft; margin

Accepted 7 Dec 2001

95

Ng:

gentlyconvex,Orbits

veryNew

hardlyspeciesof Neoliomera

deflexedfromdownwards.

ChristmaslighterIsland

coloured.

small;

cornearelatively

small

but

for light-coloured

pigmented;

ocularpedunclewithgranulesofsome distancevarioussizes.

Supraorbital

orbitalangle

markedgranule.

Infraorbital

prominent

teeth,

Anterolateral

sharp

and

granules3 largeevenly-spaced

third;

widestpoint

two-thirdsof carapace

justcarapace

gentlyconvex,ridge

closelyset

folding

short,

passes

outer

edge

transverse
just

transversely.
orbitalhiatus,orbit;

basal

segment

large.

Surfaceofscattered

long

setae

which

partiallyandsubmarginal

dilated,

wit~

Outer

small.

wIthout

surfaceofbut.

ofthoseonmore

rounded;Outer

surfacestrongly
marginsubparallel
margin.
flagellum

justreaching

epistome

angular

proximally,dea.lmostslIghtly

medianwithlock

developed.

cleft.

lateralmargins

anteroexternal

not dIstInctly

almostproduced,

relatively

reaching

togentlyalmostandconcave;straight,

anterior

GI

ong,

dlroa

I

granulessurfaceof

1

C

suturebetween between
sternites sternites
3 and 43 only
and 4visible
deep, complete;laterally, mediansutureby gently

transverse

symmetrical.

depression.

ofmerus,

numerous

sizes, those

carpusandroundedon dorsal

rounded,inner distal

without

distinct

palm,

outer

longitudinal

Outermarginsangle

spinesof
cuttingteeth,

excavated,

subspatuliform

2 main tufts

of long,completely

stiff

tip

the

granulesholotype,

andappendages,

moreeroded,onare no .sign~fic~t
almostgenerallylarger.

Carpuscurved,in form,eye,segments

t a

1

part

gen

elongate,htl

ygentlynumerous.

WIt

long

very

SOlSh

rtd.

t a

1

with

2-3

specimen,severalinner

surfacesurfacebrightwith

which

Etymology.

-The

Latindark

used as a noun

brown

with

tip

96

(Fig.

"cerasinus"

ofthecharacters.
carapacetendtobelower

age-related.
withevendescribedcomm.).

theiras redThe

whenorThere
GIs

in lifeJapanesestill

fresh, isI).

speciesfor

IS largermost

was photographed

red in life

setae on each finger.

waspers.

Japan

Into

In

differences,Kirkendale,dilatedpart

is probably

holotype(L.

fr?magrees

however,-TheColour.

thansegments

medianIn form.

shorterwith

innertor,but
theIdentIcal

teeth. Merus

fingermargins

nakedd.
ISbetween

but thisvarying

simplepigmented

innerthanThecoveredeachd.
ape,

specImenofFingers

toproximally,withhs-Thechelaeor teeth.

surfaceG2ae.

granules2 distinct

grooves,developed

and

with

microscopicallyproffilnently

margintse

Vanation.

coxal.

Chelipeds

6smoothh-s

notsegment
and juntIont l'u 1f orm s tru cture.

anonlyandvarYIng

d 2 f
d1
1
d buse,not c ear y separateutf
1d.sparow 0 granu es emarcatIng
segments;

part represented

5youtwards,..

umose

rounded1-3
lateralgranular.

b1

curvIngong.

entIre

long,

stout

1

broad,

segments
thantelsontriangular,
lateraltip rounded;surfaceofsegments

1-3 prominently

completelyfused,notdiscernible,

broader

granulatedurn

Dactylus
styliform,

Dactylo-propodalconcave;

6

4 weakly

relatIvely'

Dactylus

gentlysegment

segment

11tip.

withsegments
3-5
separating
segments

almostageserrate.

propodus,

distalappearingpart

SIzes; sternItes. thd ..
WI
In IstInct

wellcorneous

granular,

Exopodgranular;

intrapezoidal,

quadr~te:finelysubequaltel sonMerus

surfaces
granules.

long,unarmed,inserrated,

small

or

to

with

unevensubmarginal

and propodus

lengthMargins

cristate,withgranularsulcusdistalwIthandsurfaceof carpus

dorsalcovered..

withmarginsouterstrongly

Abdomensutures..P

surfaces

appears

regIons.

sternum

Gonoporemarginnot...tapering;ThoracIc

sharpness,

oblIquebut rounded,,marginadjac~nt

depressed.

merus

on dorsal

~nfl

0

those

medIangently

fge

not

than

dIstInct.

part

margins.

mediallyndges.

thosetranslucent

surfaces

marginssub~e~tangular,segments

simple,marginswell

allobscuresventralpalm
beforeelongate;

of

short

granu.lose,

smaller

mediantosubrectangular,

varyingandge.ntly

IschIU~
margInofofprominently
Marginsoutergranules;

exceptinto

patch.

...margins
thIrd maxIllIped

gran~lessubm.edIan,

numerous
size,

beforedist~nctdIscernIble

one-

dark brownreachingand outer surfaces

notwithdep~essedtransversel~;pos~erior~arginstraight
from frontal
VIew, WIth medIan part

Endostome

legs

linedvarious

innerdeveloped

longest.

Antennalthroughofrelativelywithgranules

wellby last large

beginning
Posterior

into

pair

on posterior

margin.

on bothAmbulatory

withpigmented

tip, pigmentation

secondto be larger,

denotedbeforeposterolateral

Antennules

granulesPollextubercles.
of

tend

dilating

without

large

roundedwithofgranular,orconvex;

on anterior

granule,roundedstrongly

thoselateralexternal

largermarginsizes,concavegranular;slightly

spinesmarginnumerous

marginbyand Japan

namecherry

in apposition.

is derived

coloured.

Thefromthenameis

THE RAFFLES BULLETIN OF ZOOLOGY 2002

Fig. 2. Neoliomera cerasinus,new species.a, b, holotype
male (32.0 by 19.2 mm) (WAM), ChristmasIsland; c, male(39.2 by 24.1 mm) (ZRC). a, overallview; b, c, carapaces.

Fig. 1. Neoliomera cerasinus,new species,colour in life,
male (39.2 by 24.1 mm) (ZRC). a, dorsal view;b, ventral view; c, inner surface of chela. PhotographcourtesyofY. Fujita.

Remarks. -The subfamily Liomerinae currently
contains six genera -Actites Lanchester, 1901,
Bruciana Serene,1977,Liomera Dana, 1851, MeriolaDavie, 1992, Neoliomera Odhner, 1925, andParaliomeraRathbun,1930(seeSerene,1984),with 53
recognised species (unpublished data). Neoliomera
Odhner, 1925 (type species ZozymuspubescensH.
Milne Edwards, 1834),is the secondlargestgenusin
the subfamily, with 15 recognised species,viz. N.
demani Forest & Guinot, 1961,N. insularis (AdamsandWhite, 1849),N. intermediaOdhner,1925,N.lippa

97(Nobi1i, 1905), N. nobilii Odhner, 1925, N. ovata
Tweedie, 1950, N. praetexta (Rathbun, 1906), N.
pubescens (R. Milne Edwards, 1834), N. richtersi (DeMan, 1889), N. richteroides Sakai, 1965, N. sabaea(Nobi1i, 1905),N. striata Buitendijk, 1941, N. sundaica(De Man, 1888), N. themisto (De Man, 1889) and N.
variolosa (A. Milne Edwards, 1873) (see Odhner, 1925;Tweedie, 1950; Serene, 1984; Davie, 1992).
Of the species that have very broad carapaces(width to length ratio greater than 1.60), poorly
defined carapace regions, do not have any clearly
defined anterolateral lobes or teeth, and do not havethe frontal and anterolateral margins emarginated as arim, Neoliomera
cerasinus, new species, isperhaps closest to N. nobilii
Odhner, 1925.
Neoliomera cerasinus, however, can easily be
distinguished from N. nobilii, in that its carapace is
proportionately broader, the widest point of theNg: New speciesof Neoliomera from ChristmasIsland and Japan

Fig. 3. Neoliomera cerasinus,new species,holotype male
(32.0 by 19.2 mm) (WAM), ChristmasIsland. a, posterior
part of carapace; b, third maxillipeds, antennules andantennae;c, anteriorpart of thoracic sternum.

carapace is at the junction of the antero- andposterolateral margins (vs. well before thejunction), more produced and somewhatmore acutefront, proportionately smaller orbits, moregranular posterior carapace surfaces and posterior
carapace margin, the carpus of the cheliped has
two well developed spines (vs. two low teeth),
relatively shorter cheliped fingers, proportionately
longer ambulatory meri, relatively much longer
ambulatory dactyli, and the distalmostpart of the G1
is relatively short(vs. prominently elongate),with thedorsal margin lined with numerouslong setosesetae(vs. glabrous)(cf. Odhner, 1925: pl. 2 fig. 9; Serene,
1984: Fig. 29, pl. 9B). In any case,N. nobilii is only
known from the Red Seathus far.
One species not considered by Serene (1984)
in his accountis N. ovata Tweedie, 1950,describedfrom Pulau Aor (Peninsular Malaysia) in theFig. 4. Neoliomera cerasinus,new species,holotype male
(32.0 by 19.2 rnrn) (WAM), ChristmasIsland. a, right chela(outer view); b, right chela (inner view); c, right lastambulatoryleg.

SouthChina Sea.This species,however,hastwo low
but distinct lobes on the anterolateralmargin and its
carapaceis much smoother(cf. Tweedie, 1950: 90,
Fig. 3).
Both specimensof N. cerasinuswere obtained frominside marine caves. The species, however,does not have any special adapations to a
cavernicolouslifestyle, other than perhapsthe orbits
are relatively smaller than other congeners,although
it is still not as reduced as that in troglobites(obligate cavernicoles). The life colours, a bright
red, also suggests that it is not an obligate
cave-dwelling species.

98THE RAFFLES BULLETIN OF ZOOLOGY 2002

BA,I1.

cIEFig.

5.

Neoliomera

cerasinus,

A,mm;

Scales:B= 2.0

newC-E

species,

holotypemale(32.0by19.2mm)(WAM),

ofSouthSmith,
authorYoshihisa

specIes..,

isveryFujitaforthtlor

ecologyeof

thegratefulsto

passingdy,

Lisa

Kirkendale

thismosthimdu

tht

elf

theinteresting.

anandcommen"CapeCentralths

Africa,in theonetaxon.

ofGoodAfrica".

Eld

er an d C 0., pp.
T.,
1925.

CITED

Polynesiadu(4)14(A2):
Guinot,D.,

Deepwater(Crustacea,Museum

xanthid

Decapoda,

National
501-561,1978.

pIs.

Decapodes
Francefrom

Xanthoidea).

FrenchBulletinNaturelle,Paris,

South

W.

S.,

1838.

Africa;being

chiefly

collected

E, leftevolutive

Brachyoures.
new

Illustrations

a portion
duringof

theanG2.

Crabs

Text,
Kodansha

pp.

1984.

du

Xanthoidea:

Xanthidae

Carpi1iidae

etTropicale,

24:1-400,

PIs.

F.,

Aofnatural
theSouth

Tweedie,M.

W.

history

Island,Southinterior

Museum,21:

99

Platesoccidental

China
83-96.

theadjacent

pp.

xxix

Volume,etetMenippidae

1950.

Handlingar(Ny1-5.

Decapodes

211-ofderKungliga

seas.
+pp.

In

773pp.,
1-16,

pIs.

Tokyo.

Crustaces

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1-461,
Ltd.,

byofGoteborgs

andEnglishout

Exploring

London,pIs.

of Japanvolumes;Andrew

IllustrationsI.

10-92,

112(3):

Annulosa

for1 - 75 , p 1 s. 1 - 4 .
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et Belgique,

T.,
three

1-13.

d'une

biologiquecrabs

d'Histoire

Principes

Crustaces

leftand

Xanthidae.

Tidsfoljd),
Sakai,

1992.

direction

1835,

Hope
In:ofVetenskaps-ochF.,

the1834,

Zoology

Odhner,LITERATURE

P. J.

A-D,

underyears

Krabbenfamilie

Davie,

Island.

= 0.5mm.

ACKNOWLEDGEMENTS

The

Christmas

D

Brachyoures
dela

Mer

Trapeziidae.
-A.

deRouge.

Addendum
Crosnier.

Faune

1-48.
collection
Sea.

Bulletinofcrabs
offromtheAorRaffles