Calcinus hermit crabs from Easter Island, with biogeographic considerations (Crustacea: Anomura: Diogenidae)

7 Pages·2003·5.5 MB·English

by  J Poupin

MemoirsofMuseumVictoria60(1):91-97(2003)
ISSN 1447-2546(Print) 1447-2554(On-line)
http://www.museum.vic.gov.au/memoirs
Calcinus hermit crabs from Easter Island, with biogeographic considerations
(Crustacea: Anomura: Diogenidae)
JosephPoupin', ChristopherB. Boyko^and GuillermoL. Guzman^
'InstitutdeRecherchedeI'Ecolenavale,IRENav,Ecolenavale,Lanveoc-Poulmic,BP600,29240BrestNaval,Prance
([email protected])
^DivisionofInvertebrateZoology,AmericanMuseumofNaturalHistory,CentralParkWestat79thStreet,NewYork,
NY10024,USA([email protected])
^MuseodelMarUniversidadArturoPrat,Casilla 121,Iquique,Chile([email protected])
Abstract Poupin,J.,Boyko,C.B.,andGuzman,G.L.2003.CalcinushermitcrabsfromEasterIsland,withbiogeographicconsid-
erations (Crustacea: Anomura; Diogenidae). In; Lemaitre, R., and Tudge, C.C. (eds). Biology of the Anomura.
Proceedings ofa symposium at the Pifth International Cmstacean Congress, Melbourne, Australia, 9-13 July 2001.
MemoirsofMuseumVictoria60(1): 91-97.
Promcollectionsmadein 1998and1999,threespeciesofCalcinusarerecordedfromEasterI.: Calcinuspascuensis
Haig, 1974; C. imperialisWhitelegge, 1901; and C. vachoniPorest, 1958.AredescriptionofCalcinuspascuensis is
givenandaneotypeisselected.OccurrenceofCalcinusimperialisisconfirmedbyexaminationofalmost80specimens,
includingmanyjuveniles. Calcinusvachoniisrecordedforthefirsttimefromtheisland.TheEasterI. Calcinusfauna
iscomparedwiththatofotherlocalitiesinthePacific,andbiogeographicaffinitiesarediscussed.
Keywords Cmstacea,Anomura,Diogenidae,Calcinus,biogeography,EasterIsland
Introduction genus Calcinus were obtained, with only three species repre-
Easter Island (27°10'S, 109°20'W), located 3800 km off the sented: C. pascuensis Haig, 1974, C. imperialis Whitelegge,
Chileancoast,andseparatedby2200kmfromPitcairnI.tothe t1h9e0s1e,naenwd Cc.olvlaeccthioonnisEaorreesotf,i1n9t5e8re.stAlftohroautghlealsotwtiwnodirveearssointsy.,
west,isthemostisolatedislandintheSouthPacific.Thecoast
Eirst, they allow a redescription of C. pascuensis, previously
lineisrockywithonlyafewsandyandcobblebeaches.Itscli- known fromonly a single incomplete male. Second, they can
m2a2t-e24°isCsiunbtthreopsicuamlm;ert,heansdur1f6ac-e18°seCaintetmhpeewrianttuerre.Arlatnhgoeugihs beusedtodiscussthebiogeographicaffinitiesofEasterI.with
neighbouringlocalitiesintheIndo-Pacificregion.
the water is cool, there are extensive amounts ofliving coral
aroundtheislandbutdiversityofcoralspeciesislow.Because Materialsandmethods. Mostofthe specimens werecollected
ofits isolated position andhigh percentages ofendemic taxa, between 16 Aug and 1 Sep 1999, during the United States
and despite a surface area ofonly 106 km^ Easter L, in con- NationalParkServiceExpeditiontoEasterIsland.Thecollec-
junctionwithnearbysmallSalayGomezL,415kmtotheeast, tors were Christopher B. Boyko, John Tanacredi (United
is usually treated as a distinct biogeographic province in the States National Park Service, Gateway), Rick and Susan
Pacific (Briggs, 1974). Reanier, Ellen Marsh, Dennis Hubbard (Oberlin College,
TheAnomuraknownfromtheislandconsistsofarofonly Ohio), and Henry Tonnemacher (Seven Seas, Ltd., Virgin
seven species: Calcinus pascuensis Haig, 1974, Pylopagur- Islands). Afew additional specimens were collected during a
opsis garciai McLaughlin and Haig, 1989, Petrolisthes 1998Expedition(19-24Aug).Theaimofbothexpeditionswas
extremus Kjopp andHaig, 1994,Albuneidae sp. and Calcinus primarily archaeological. Most hermit crabs were collected
imperialis Whitelegge, 1901 (DiSalvo et ah, 1988), intertidallybyhand, and afew by SCUBAindepths downto
Phylladiorhynchus integrirostris (Dana, 1853) (Baba, 1991), 23 m. Otherspecimens werecollectedby Guillermo Guzman,
and Tylaspis anomala Henderson, 1885 (Lemaitre, 1998). In during the oceanographic CIMAR-5 Chilean cruise, on board
1998 and 1999newintertidalandshallowwatercollectionsof the AGOR Vidal Gormaz from 29 Oct to 15 Nov 1999. The
hermit crabs were made during the Chilean CIMAR-5 cruise Calcinus were collected by hand in the Easter I. locality of
and the American United States National Park Service Hanga Roa and its adjacent shores. An additional specimen,
Expeditiontotheisland.Morethanahundredspecimensofthe collected at Easter I. in March 1984 and deposited in the
92 J. Poupin,C.B. BoykoandG.L.Guzman
collections of the Museo Zoologico Universidad de Left cheliped larger than right (Pig. lb). Merus subtriangular in
Concepcion, Chile, was obtainedthroughthecourtesy ofDrJ. cross-section;outerandinnersurfacesflat;outerlowermarginusually
N.Artigas. withsinglespineatdistalangle;innerlowermarginwith2or3distal
The measurement (mm), shield length, taken from tip of spines.Caipusbroad,muchshorterthanmeras.Outerfacewithproini-
rostrum to posterior edge of the shield, is included for all nent submedian tubercle, occasionally with few additional smaller
NsaptecuirmaelnsH.isAtbobrrye,viaNteiownsYaorrek:;AMMNNHH,N,AmeMruicsaenuMmusneatuimonaolf ttsuimbpaeplrelcdelreisns;pjdeuicvseitnmoiellnaetsse,.rafUlepmwpaerargdidminatriwoginitanhlswpmioatslhtlersgiironagrnlueslpietnesersom.rintIaunlbneesrrpcilaneens,dasnlpdoi,wneeir-n
d’Histoire naturelle, Paris; MZUC, Museo Zoologico faces smooth. Chela 0.9-1.6 as long as shield and 1.4-2.0 as long
Universidad de Concepcion, Chile; P2, P3, second and third as width. Outerface ofpalmregularly convex, slightly tuberculate;
4-
pereopods. upper margin with row of 6-8 spiny tubercles; outer lower margin
rounded, smooth or slightly tuberculate. Inner face rounded, with
tuft ofsetae below articulation ofdactyl; innerlowermargin some-
Calcinuspascuensis Haig, 1974 what angularwithrow offaintgranules, prolongedby sharprowof
Figure 1 tuberculesoninnerfaceoffixedfinger.Pingersspoonedattips.Dactyl
0.6 time as long as entire chela, with tufts oflong setae on lower
—CalcinuspascuensisHa—ig, 1974: 27,figs 1-6(typel—ocality:Easter margin; cuttingedge with2 or 3 large calcareous teethonproximal
I.). Retamal, 1981: 19. DiSalvo et al., 1988: 458. Poupin and 0.5. Pixedfingerforminglargehiatuswithdactyl; cuttingedge with
McLaughlin, 1998;24. large calcareous tooth on distal 0.5, and 1 or 2 smaller teeth on
Material examined. Neotype (herein selected). Easter I., offHanga proximal0.5.
O1t.e3a-, 26 Aug 1999, 21 m, D. Hubbard, 1 male 5.3 mm (AMNH Rightchelipedshorterthanleft,reachingtobaseoffingersofleft
18177). chela, orlittle beyond, whenextended(Pig. Ic). Meras compressed;
4.0Omthmer(spAeMciNmHens18(1a7ll8)f,ro1mfEeamsatlereI3.)..9OmffmAn(aMONKHeNkeP,gPo5i9k4e8,).1mOarloei euapcpherwmiatrhg2inorsh3ardpiswtailthspfienews.loCnagrspeutsaem;uocuthershaonrdteirnntehranlomweerrasm;aroguitnesr
Point, 1 female 1.5mm(AMNH 18179).HangaTeeOVaihu, 1 male face withmedian tubercle and 1 or2 additional smallerones; distal
1.8 mm (AMNH 18180). La Perouse Bay, 2 males 1.9-2.1 mm, 1 margin with several corneous-tipped tubercles, somewhat eroded in
female 1.7mm(AMNH18181).Piko,3males 1.7-2.0mm,2females largerspecimens,thoseproximatetoupperandlowermarginslarger
1.7mm(AMNH 18182).TePitoKura, 1 male3.0mm,3females than others; upper margin with 3 strong spines, the distalmost one
1. 2.2mm(AMNH 18183). Piko, 1 male 3.6mm(AMNH 18184). largest. Outer face ofchela with distally plumose setae and several
HangaRoa, 1male2.6mm, 1female2.4mm(MNHNPg6092). tubercles in distal upper half; upper margin with 5 strong
corneous-tippedspines.Pingersspoonedattips.Dactyl0.5aslongas
Diagnosis. Ocularaciclewithasingleterminalspine.Chelipeds, wholechela;uppermarginwithadoublerowof4or5smallcorneous-
P2 andP3 withlonganddistallyplumosesetae, typicallywith tipped spines; cuttingedge with two median calcareous teeth. Pixed
club-like aspect. Outer face of left palm regularly convex. fingerwithouterfacetuberculate; cutting edgeforming smallhiatus
Uppermarginofrightpalmwith4or5 strongcorneous-tipped withdactyl,armedwith2-4triangularteeth.
spines. Dactyls ofP2 and P3 equal to or slightly shorterthan P2noticeablyexceedingcheliped(Pig.Id).Merasaslongaspropo-
propodi; distal degree of setation similar for both pereopods, dus; lateralandmesialfacescompressed; dorsalandventralmargins
withlong, distally plumose setae; ventral marginwithrow ofsome-
withoutdistalbrushofsetaeonP3. Telsonwith2-16 (usually whatspinygranules;distolateralanglearmedwithsinglespine.Carpus
10) spines on lateral and posterior margins of left posterior 0.6 as long as propodus; lateral face inflated, mesial face flattened;
lobe,and2-7 (usually6) spinesonrightposteriorlobe. dorsalmarginwithstrongsubdistalspineandsmallerposteriorspine;
Redescription. Shield0.8 as broad as long; anteriormarginbetween ventralmarginwithfewplumosesetae.Propodusfeeblycurved, sub-
rostrumandlateralprojections slightlyconcave; anterolateralmargin ovateincross-section,slightlyshorterthanshieldlength,withseveral
setose;anterolateralplateofbranchiostegiteaimedbyrowofspinules tuftsoflong,distallyplumosesetae.Dactylstronglycurved,about0.9
ondorsalmargin.Rostrumbroad,obtuselytriangular,largelyexceed- as long as propodus, terminating in strong corneous claw; ventral
ingsmalllateralprojections.Ocularaciclesubtriangular,terminatedby margin with few long simple setae, amied with 6-9 acute spines.
single acute spine. Ocular peduncle 0.8-1.0 as long as shield, left P3 slightly overreaching tip of cheliped (Pig. le). Merus about
slightly longerthanright; diameterofcorneaincluded 5-7 times in as long as propodus; lateral face smoothly curved; mesial face
peduncularlength(Pig. la). slightly concave; dorsal and ventral margins with several tufts
Antennularpeduncle extending to distal 0.25 ofocularpeduncle; oflong, distallyplumose setae; distolateral anglewith spine. Carpus
basal segment usually with 3 spinules at ventrolateral distal angle; 0.7 times as long as propodus; dorsal and ventral margins with
penultimate segment unarmed; ultimate segment unarmed, equal to plumose setae; dorsodistal marginwith strong terminal spine, some-
O.33ofshieldlength.Antennalpedunclereachingtodistal0.33ofocu- timeswithsmalleradditionalposteriorspine.Propodus0.8aslongas
larpeduncle,furnishedwithlonganddistallyplumosesetae.Pirstseg- shield length, subovate in cross-section, with tufts oflong plumose
ment minutely spinose at ventrolateral distal angle. Second segment setae mainly near dorsal and ventral margins. Dactyl as long as
with dorsolateral distal angle produced, terminating in strong bifid propodus; setation weak and similarto dactyl ofP2; ventral margin
spine; dorsomesial surface inflated, produced as strong spine. Third with7-9acutespines.
segment with ventrodistal spine. Pourth segment with distodorsal Sternite of P3 with anterior lobe subrectangular; ventral surface
spine. Pifth segment long and unarmed. Antennal flagellum over- swollenin2roundedprojections,furnishedwithsetae.Telsonwithleft
reaching distal end of P2. Antennal acicle surpassing distal end of posteriorlobeconsiderablylargerthanright;lateralmarginarmedwith
penultimatesegmentofantennalpeduncle,producedasstrong spine, 8-10spines,posteriormarginwith3-6spines(Pig. If).Rightposter-
upwardly curved; dorsolateral margin with 2 spines; dorsomesial iorloberegularlycurved,without clear separationbetweenposterior
mai'ginwith2-3spines. andlateralmargins,armedwith6-8spines.
Calcinusfrom EasterIsland 93
Figure 1. CalcinuspascuensisHaig, 1974,neotypemale5.3mm(AMNH 18177): a,anteriorportionofshieldandcephalicappendages;b,left
cheliped,outerview;c,rightchela,outerview;d,leftP2,lateralview;e,leftP3,lateralview;f,telson,ventralview;g,detailofsetae,fromven-
tralmarginofP2.Scalebarsequal 1mm.Colourpatternafter18monthsinalcohol.
Colour. After18monthsinalcohol,colorationstillveryclearonlarg- Strombus maculatus, and perhaps also Erosaria caputdraconis,
er specimens. Shield orange, fading to white posteriorly. Posterior Fossarus cumingii, Neothais nesiotes, andNodilittorinapyramidalis
carapace white. Ocular acicle pink to orange, terminal spine white. pascua(emptyshellsofthesemolluscswerefoundinvialscontaining
Ocularpedunclewithbasalpinkring(almostwhitein smallerspeci- loosecrabsofdifferentspecies).
Amenntse)n,numlaerdipaenduonrcalnegweitarhead,araknodrannagrerobwlowthchietseorninpgrocxloismealtosecgomrenneta;. Remarks. TheholotypeofCalcinuspascuensiswaslostduring
mediansegmentandproximalhalfofterminalsegmentorange;distal thetransferoftheAllanHancockFoundationcollectionstothe
halfofterminalsegmentpalebluetowhite;flagellayellow.Antennal LosAngeles CountyMuseum(G. Davis,pers. comm.).Asthe
peduncleorangeon4proximalsegments(spineswhite),yellowonter- original description of the species was based solely on the
minalsegmentandflagellum.Antennalacicleorangewithwhiteattips incompleteholotype,aneotypehasbeenselectedherein.
of spines. Cheliped with large irregular brown patches on pink to A few morphological variations have been observed. In
cream-whitebackground. Outerandinnerfacesofmeruswithbrown juveniles smaller than 1.6 mm the ocular peduncles are only
proximalanddistalpatches,separatedbywhitemedianarea;outerand 0.6-0.7timesaslongasshieldinsteadof0.8-1.0inlargerspec-
innerfacesofcarpuswithmediansubtriangularbrownpatches;outer imens.Theocularaciclehastypicallyasingleterminalspineon
faceofchelawith2brownmedianpatches, alargeoneontheupper 17 specimens outof20,butafew otherarmamentshavebeen
hmaeldfiaanndbarosmwanllpaetrcohn.eP2alaonndgPve3ntwriatlhmpairngkinb;acikngnreorufnadc.eLoaftecrhaellafawcietsho1f observed: 1additionalspinule,unilaterally;twoterminalspines
meri,carpiandpropodiwith2orangebrownstripes,forming 2con- oneach acicle; andtwo spines on one acicle andthree onthe
tinuouslinesonthe3 segments.Mesialfaceswithsimilarpattern,the other.Theleftchelapresentsseveralvariationsaccordingtosex
2linesbeinglessregularandreducedtoelongatedspotsonmeriand or size. It is usually shorterin females, only 0.9-1.1 times as
carpi.Dactylswithfewelongatedorangebrownspots.Abdomenand longas shieldversus 1.0-1.6inmales.Theaspectofitsupper
telsonwhite. marginvaries fromalmost smoothto armedwitharow ofsix
Distribution.EasterI. to eight spines. These spines are more acute injuveniles and
also cover the upper half ofthe outer face ofthe chela. The
Habitat. Hardbottoms,fromshoretodepthof23m.Gastropodshells armament of the telson varies with size. In specimens larger
used are: Coralliophila violacea, Nerita sp., Planaxis akuana. than 3.0 mm, it consists of 11-16 spines on the left posterior
31
94 J.Poupin,C.B. BoykoandG.L.Guzman
lobeandsixtoeightontherightposteriorlobe.Insmallerspec- onits dorsalmargin(no spinules). Leftchela0.8-1.3 times as
imensthenumberofspinesisreducedtotwotoeightspineson longas shield,comparativelylargerinadultmales. Outerface
theleftposteriorlobeandtwotothree spinesontherightpos- ofpalmfeeblygranular,withseveralproximaltubercles;lower
teriorlobe. halfwith2or3circularorsubcirculardepressions;uppermar-
Inarmamentoftheocularacicle(simple)andtelson(sever- ginarmedwith3-5 spinytubercles;lowermargindenticulated
alspinesonbothposteriorlobes),aspectofouterfaceoftheleft andcarinate,carenacontinuingontofixedfinger(seeremarks).
chela (regularly convex), and similar sparse pilosity on distal Carpus armed with several stout spines along anterior and
P2 and P3, Calcinuspascuensis is most similar to C. incon- uppermargins and onouterface. Rightpalm with4 or 5 cor-
spicuus Morgan, 1991. However, the two species are easily neous-tippedspinesonuppermargin;outerfacetuberculate.P3
differentiatedbycoloration: chelipeds, P2 andP3 in C. incon- with distinct brush of setae on ventral margin of dactyl and
spicuus are almostuniformly coloured while in C. pascuensis distalpartofpropodus;dactylabout0.8timesaslongaspropo-
therearepatchesonthechelaeandstripesonP2andP3.They dus.Telsonarmedwithsinglespineonterminalmarginofeach
also differ in armament of the telson, the spines of the left posteriorlobe.
posterior lobe being present only on the posterior margin in Colour, (livecolorationfromPoupin, 1997).Shieldandocularpedun-
C. inconspicuus, whereas they are ontheposteriorandlateral cles green olive. Antennular and antennal peduncles yellow. Chelae
marginsinC.pascuensis. green olive with purplish-blue spines and tubercles, tip of fingers
Calcinuspascuensisisdistinguishablefromthe otherIndo- white.Dactylsofchelaewith2redspotsnearbase,oninsideandout-
West Pacific species by the remarkable coloration ofwalking side. P2 and P3 banded in light yellow, black, and green olive.
legs. A similar pattern is observed in C. anani Poupin and Abdomenandtelsonwhite.
McLaughlin, 1998, butthe stripes on the propodi and dactyls After 1.5yinalcohol,colorationstillclearonEasterI. specimens
merge in an intricate network ofreticulations. Calcinuspas- although slightly different from live coloration. Shieldwhite, some-
cuensisisalsouniqueinthesetaeontheouterfaceoftheright timescreamondistalhalf.Antennularandantennalpeduncleschlorine
chela, and on the dorsal and ventral margins of P2 and P3. yellow. Palms of chelae orange to brown, fading to white distally;
tuberclesandspinesblue.Dactylsofchelaewith2redspotsnearbase,
These setae are distally plumose, which give them aclub-like on inside and outside. P2 and P3 banded in white, red-brown, and
aspect (Fig. 1 g). Although plumose setae are sometimes orange.
observedinotherspecies,theyarenotclub-likeshapedandare
insertedonlyonthedistoventralmarginsofP2andP3. Distribution. South Pacific 14-34° S. Eastern Australia to
Easter L, including Vanuatu, New Caledonia, Norfolk I.,
CalcinusimperialisWhitelegge, 1901 Kermadec Is, and French Polynesia. Not found in the Indian
Ocean orinNorthPacific, andthereportfromthese areas by
HowCaelcIi.n)u.s—GirmapnertiaalnidsMWchCiutlelleogcghe,,11990071::1485,4.pi—.C9hi(lttyopne,l1o9ca1l1i;ty5:5L2o.r—d ForestandMcLaughlin(2000: 79)iserroneous(J.Forest,pers.
comm.).
DiSalvoetal., 1988:4—58.—Morgan, 1991: 882,figs21-2—3.—Tudge,
1995: 11,pi.—1,fig. If. Poupin,1997;697,figs3f,5c,7d. Forestet Habitat. This species is a non-obligate coral associate (genus
al.,2000: 15. ForestandM—cLaughlin,2000:79.— Pocillopora).OnEasterI.itusesgastropodshellsofCaducifer
NotCalcinusimperialis. Wooster, 1984: 130. Poupin, 1996: 14 decapitata englerti, Erosaria caputdraconis, Fossarus cumin-
(=CalcinusisabellaePoupin, 1997).
gii, Neothais nesiotes, Nerita sp., Planaxis akuana, Pascula
Materialexamined(allfromEasterI.). HangaPoukura, 1 female 1.8 citrica, andNodilittorinapyramidalispascua. Two specimens
mm (AMNH 18185). Hanga Tee, 1 male 1.5 mm (AMNH 18186). (AMNH 18187) were parasitised by the bopyrid isopod,
EdaisstceorloIu.,re2dmaslpeesci1m.e9n-s2.01mmmale(A1M.9NmHm1,81817)f,em3alfeema1l.6esm1m.7-(2.A9MmNmH, PseudionellaakuakuBoykoandWilliams,2001.
18188). Easter I., 1 female 2.7 mm (AMNH 18189). Tongariki, 1 Remarks. The occurrence of Calcinus imperialis in Easter L,
female2.1mm(AMNH18190).HangaTeeOVaihu,discolouredspec- althoughalreadymentionedbyDiSalvoetal. (1988),hadbeen
imens 2 males 1.3-1.7 mm (AMNH 18191). HangaTee O Vaihu, 6 overlookedinthe taxonomic literature. These new collections
Pmc11eoa.8lr1l1-oo9e1u3us.)rs4.ee1d.T4mB-easm3yp,.P,e4ict2i1ommmmefKane,ulsmreaa4sl,6ef31ej.um19mv.a-a0el3nle.imes8lsme1s,m2.m4.0-35,.2-.92jd-2.ui91vsm.ec4mnmoim,llm,oeums1r1ej0du(.fv9eAse-mnp1Mai.ellNc0eeiHmm11e..mn183s81mm(92mm2A,,)m.MaddlNiiLessHas-- riaterpeisoEtrxvhtaeeermdsy,ienrccaeootvnmeidaomlrnosencioonfatrrrdaoCsouapfneldtcchiiitfnshiuecsspvieascrliaiimnaepdtse.irooinnasl.EiaUssntuessrpueIa.cliamnaedrnmssahmoehwenrttehioanft
coloured specimens 7 males 1.0-1.7 mm, 4 females 1.2-1.5 mm theocularacicleincludesoneadditionalsmallspine,ononeor
(AMNH18194).Anakena,2males1.6-3.5mm,2females1.6-2.2mm both sides (13 specimens out of 79) or up to three terminal
(AMNH 18195). Anakena, 2 males 1.9-3.5 mm, 2 females 1.6-3. spines, on one side (a single specimen). The distal brush of
mm, discoloured specimen 1 female 1.3 mm (AMNH 18196). One setaeonP3 is somewhatweakonafew small specimens. The
Makihi, 1male4.4mm(AMNH18197).HangaRoa,2males2.8-4.4 two or three circular or subcircular depressions on the outer
mm, discoloured specimens 9 males 1.3-1.9 mm, 3 females 1.6-2. faceofthechelaareattenuated,oreventotallyabsent,onspec-
mm(MNHNPg6093). imenssmallerthan2.0mm.Theouterfaceofthepalmiseither
Diagnosis. Ocular acicle with a single terminal spine. Ocular regularlyconvexoronly slightlyconcaveonitslowerhalf. In
peduncle 0.7-1.0 times as long as shield; diameter ofcornea thesecasesidentificationcanstillbemadebycarefulexamin-
included approximately 5 times in peduncular length. ationofthelowermarginsofthepalmandfixedfinger, which
Anterolateralplateofbranchiostegitewithfringeoflong setae arealmostalwayscarinated.Incombinationwiththearmament
CalcinusfromEasterIsland 95
oftheocularacicleandtelson,thischaracterwasveryusefulin vachoniissimilartoCalcinusgoutiPoupin, 1997,fromFrench
identifying many juveniles lacking colour. The carina was Polynesia,andCalcinuslaurentaeHaigandMcLaughlin,1984,
missingonly ona 1.6mmfemale (AMNH 18188) althoughit fromHawaii. However,thesethreespeciesareverydistinctive
waseasilyidentifiedasC. imperialisbythefaintremainsofred in their coloration (see Poupin, 1997; Hoover, 1998). The
spotsatthebasesofthedactylsofthechelae. ocularpeduncleisgray-bluetocreamwithalargedarkpatchin
C. vachoni-, orange with narrow whitering close to cornea in
CalcinusvachoniForest, 1958
C. laurentae-, and proximally pink, grading to pale pink or
CalcinusvachoniForest, 1958:—285, figs2, 3, 9,—10, 15, 19 (type whitedistallyinC. gouti.Thedistalantennularsegmentisblue
locality:nearNhaTrang,Vietnam).—Baba,1982:58. Morgan,1990: inC. vachoni-,lightorangeorwhiteinC. laurentae-, andwhite
11, fig. 2; 1991: 905, figs 60-62. Gherardi andMcLaughlin, 1994: to cream in C. gouti. The chela is gray-blue turning to white
624.—Poupin, 1997: 712, figs 6e-f, 8a-f—Shih and Lee, 1997: 22, distally in C. vachonv, brown turning to white distally in
figs 1-3.—Shih, 1998—:93,figs33-35.—KatoandOkuno,2—001:74. C. laurentae-, and white orcream with a submedian dark spot
Calcinus seurati. Matsuzawa, 1977: pi. 79, fig. 3. Miyake,
1983: 113.—Nomuraetal.,1988: 113.—Takeda,1994: 194,fig.2.Not on outer face in C. gouti. P2 and P3 are uniformly cream in
CalcinusseuratiForest, 1—951. C. vachoni-, red-orange turning to pinkish distally in
NotCalcinusvachoni. ^Lewinsohn, 1982:53(=Calcinusguamen- C. laurentae-,andcreamwithpinkringsinC. gouti.Inaddition
sisWooster, 1984,seeDistribution). to coloration, Calcinus vachoni is also distinguished by the
Material examined (all specimens from Easter L). Los Motus, in uppermarginoftheleftchela,unarmedandoftenweaklycor-
Pocilloporacoral,1male3.7mm(MZUCFI198,3257).TePitoKura, nered, whereas it has some spines and is rounded in the two
1 male1.2mm(AMNH18198).HangaRoa,discolouredspecimens 1 otherspecies.
male1.6mm, 1female 1.7mm(MNHNPg6094).
Discussion
Diagnosis. Ocular acicle with 2-5 terminal spines.
Anterolateralplateofbranchiostegitewithfringeoflong setae Knowledge of the Easter Island Calcinus fauna has been
on dorsal margin, unarmed. Outer face ofleft chelaregularly obtained as result ofpast expeditions to the island. Since the
convex, slightly granulate; lower margin of palm rounded; first collections ofDecapodamade during the 1904Albatross
upper margin unarmed, rounded or weakly cornered. Right Eastern Pacific Expedition, more than ten scientific missions
chelawith5-7corneousspinesonuppermargin.Distalsetation have studied this fauna. The most important collections were
ofP3morepronouncedthanondistalP2butnotformingreal obtainedduringthe 1958 ScrippsInstitution ofOceanography
brush of setae. Telson with 4-9 spines on left posterior lobe DOWNWIND Expedition, with a rock dredge operated
(3-5 onposteriormarginand 1^ onlateral margin) and 3-9 between 40 and 100 m, in La Perouse Bay; the 1964-1965
spinesonrightposteriorlobe. Canadian British Columbia Medical Expedition to Easter
Island,withmanyshorecollectionsmadebyMessrsEffordand
Colour(hvecolorationfromPoupin, 1997).Oculai'pedunclegray-blue
tocreamwithalargedarkpatchofvariableextension:fromabsentto Mathias; the 1972ExpediciondeIsladePascua, organisedby
almostcoveringallthepeduncle.Antennularpeduncleanditsflagella, theInstitute Central de Biologfa, Universidad de Concepcion,
blue. Distal segmentofantennalpeduncleorange; flagellumorange. withintertidalcollectionsandSCUBAdivesbetween8and 10
Chelipedalmosttotallygray-blueturningtowhiteonfingersofchela. m; and the 1985 and 1986 National Geographic Expedition,
P2 andP3 uniformlycream. InEasterI. specimens examinedherein with intensive collections frominshore to depths of60 m, by
colorationhasalmosttotallyfaded. SCUBAdives, andalsobaitedtrapsaround 100m.Asno spe-
Distribution. Widely distributed in Indo-West Pacific, cialattentionwaspaidtotheCalcinusduringtheseexpeditions
27°N-27°S. Mauritius, Western Australia, Vietnam, Taiwan, itis possible thatmore species occur around the island, espe-
Micronesia,Japan,FrenchPolynesia, andEasterL.According ciallyinpoorlysampledsubtidalareas.Nonetheless,becauseof
to Gherardi and McLaughlin (1994), the recordfrom Somalia thelargecollectionstudiedhere,itcanbe statedthat Calcinus
(Lewinsohn, 1982) is in factreferable to Calcinus guamensis species are reasonably wellknown.AcomparisonofEasterI.
Wooster, 1984. fauna with other places in the Indo-West Pacific (Table 1)
showsthat: (1)theEasterI.faunaisremarkablyimpoverished;
Habitat. Hardbottomandfacultative associate ofPocillopora (2)theislandmustbeincludedintheIndo-WestPacificregion;
corals. It uses gastropod shells ofDrupa spp., Drupella spp.. and(3)itisadistinctprovince.
Conus spp., Mitra spp., Latirus spp., Cymatium spp., EasterI.hasaclearlydepauperateCalcinusfaunacompared
Coralliophilaspp.,andCroniaspp.(ShihandLee, 1997: 25). to other Indo-West Pacific areas. Some species that are com-
Remarks. Separationofthepoorlypreserved specimensherein mon and easily collected by hand in neighbouring Erench
reported of Calcinus vachoni from discoloured juveniles of Polynesian Islands, such as C. seurati or C. laevimanus, are
C. imperialis,canbedifficult.Thecharactersthataremostuse- absentfromEasterI.TheWesternPacifichastherichestfauna
ful are: armament of ocular acicle and telson, aspect of left (22species.Table 1)withadeclineinthenumberofspeciesto
chela,andinthecaseofonespecimen,fainttracesofcoloration theeast(18 speciesinErenchPolynesia, 11 speciesinHawaii,
(ocular peduncle, white with cream patch distally, and distal and3speciesonEasterL).Thistrendissimilartothatobserved
segmentofantennularpeduncleblue). in shore fishes (Randall, 1998, 1999). Such low
Inarmamentoftheocularacicleandtelson,generalaspects numberofspeciesinEasterI. canbeattributedtoitsisolation;
of left and right chelae, and distal setation of P3, Calcinus low surface area which reduces the chance of settlement by
96 J. Poupin,C.B. BoykoandG.L.Guzman
Table1.SpeciesofCalcinusinthewesternandcentralPacific.WesternPacific:JapantoAustralia,includingTaiwan,Micronesia,andIndonesia.
FrenchPolynesia:Marquesas,Society,Tuamotu,AustralandGambler.Speciesinboldoccuronlyinoneregion.
Western Pacific (Asakura, 2002; Asakura and Nomura, 2001; Asakura and Tachikawa, 2000; Morgan, 1991; Poupin, 1997; Poupin and
McLaughlin, 1998;RahayuandForest, 1999;Shih, 1998)
C.ananiPoupinandMcLaughlin, 1998;C. areolatusRahayuandForest, 1999;C.argusWooster, 1984;C. elegans(H.MilneEdwards, 1836);
C. gaimardii (H. Milne Edwards, 1848); C. guamensisWooster, 1984; C. haigae Wooster, 1984; C. irnperialisWhitelegge, 1901; C. incoii-
spicuusMorgan, 1991 (Australia); C. isabellaePoupin, 1997;C. kurozumiiAsakuraandTachikawa,2000(Mariana); C. laevirnanus(Randall,
1840);C.latens(Randall, 1840);C.lineapropodusMorganandEorest, 1991;C.minutusBuitendijk, 1937;C.morganiRahayuandEorest, 1999;
C.pulcherEorest, 1958;C. reviPoupinandMcLaughlin, 1998; C. seuratiEorest, 1951;C.siriusMorgan, 1991 (Austtalia); C. spicatusEorest,
1951;C.vachoniEorest, 1958.
FrenchPolynesia(Poupin, 1997;PoupinandMcLaughlin, 1998;RaliayuandEorest, 1999)
C. ananiPoupinandMcLaughlin, 1998); C. elegans(FI. MilneEdwards, 1836); C.goutiPoupin, 1997 (TuamotuandSociety); C. guamensis
Wooster, 1984;C.haigaeWooster, 1984;C.hakahauPoupinandMcLaughlin, 1998(Marquesas);C. irnperialisWhitelegge, 1901;C. isabellae
Poupin, 1997; C. laevirnanus (Randall, 1840); C. latens (Randall, 1840); C. minutusBuitendijk, 1937; C. morganiRahayu andEorest, 1999;
C.nitidusHeller,1865(TuamotuandSociety);C.orchidaePoupin, 1997(Marquesas);C.reviPoupinandMcLaughlin, 1998;C.seuratiEorest,
1951;C.spicatusForest, 1951;C. vachoniEorest, 1958
Hawaii(HaigandMcLaughlin, 1984;Hoover, 1998;RahayuandEorest, 1999)
C.argusWooster,1984;C.elegans(H.MilneEdwards, 1836);C.gaimardii(H.MilneEdwards, 1848)?;C.guamensisWooster,1984;C.haigae
Wooster, 1984; C. hadetti Haig and McLaughlin, 1984; C. laevirnanus (Randall, 1840); C. latens (Randall, 1840); C, laurentae Haig and
McLaughlin, 1984;C. morganiRahayuandEorest, 1999?;C. seuratiEorest, 1951
EasterI.(thisstudy)
C. irnperialisWhitelegge, 1901;C.pascuensisHaig, 1974;C. vachoniEorest, 1958
oceaniclarvae;subtropicalnaturewithlowseatemperatureand George E. Davis, searched for the holotype of Calcinuspas-
lowcoraldiversity; andmonotonousrockycoast, offeringfew cuensisintheLosAngeles CountyMuseumcollection,unfor-
ecologicalniches. tunatelyinvain;M.RetamalandJ.N.Artigasarrangedforthe
The affinities of Easter I. are clearly with the Indo- loan of a specimen deposited in the collections of the
West Pacific, and the island can be considered the eastern- UniversidaddeConcepcion.J.RandallandM.Tavaresaidedin
mostoutpostofthisregion.ThethreelocalCalcinusspeciesdo the bibliographic research. Eunding to Christopher Boyko for
not have affinities with any of the eastern Pacific species: theInvertebrateSurveyofEasterI.wasprovidedbytheUnited
C. californiensis Bouvier, 1898, C. explorator Boone, 1930, States National Park Service, Gateway National Recreation
and C. obscurus Stimpson, 1859. The eastern Pacific species Area, Division of Natural Resources, as part of a Science
are characterisedby the uppermarginoftherightchelabeing Museum of Long Island/Explorers Club five-year research
smooth or only slightly granulated, whereas the Easter I. expeditiontoexploretheimpacts ofElNinoevents onWorld
Calcinus,likealmostallotherIndo-WestPacific species,have HeritageSites.
fourorfivestrong,corneous-tippedspinesonthismargin.The
presenceinEasterI.ofC. vachoni,aspecieswidelydistributed References
in the Indo-West Pacific, is futher evidence of the Indo-
Asakura, A. 2002. Hermit crabs ofthe genus Calcinus Dana, 1851
WestPacific affinities ofthe island. Moreover, the occurrence
fromJapan andadjacentwaters (Crustacea: Decapoda: Anomura:
ofC. irnperialispointstothecloseaffinitiesbetweenEasterI. Diogenidae): C. areolatus Rahayu & Eorest, 1999. Benthos
and islands that lie along the southern edge of the tropical Research51{V)\ 11-20.
Pacific suchasthose ofsouthofTuamotu, RapaI., Kermadec Asakura, A., and Nomura, K. 2001. Hermit crabs of the genus
I. and NorfolkL. Asimilarobservationhas been documented Calcinus Dana, 1851 from Japan and adjacent waters (Crustacea
formolluscsbyRehder(1980: 14,figs6-9). Decapoda: Anomura: Diogenidae): C. pulcher Eorest, 1958 and
Although hardly significant for such a limited number of C.lineapropodusMorgan&Eorest,1991.CrustaceanResearch30:
species, the presence of one endemic species, Calcinus 94-110.
pascuensis, out ofthree present on the island, represents the Asakura,A.,andTachikawa,H.2000.Anewhermitcrabofthegenus
highest percentage ofendemicity for the regions separated in Calcinus from Micronesia, including new information on C. revi
(Decapoda:Anomura:Diogenidae).JournalofCrustaceanBiology
cTaobmlbein1e.TdhiwsithhigehxrtarteemoefegnedoegmriacpihtiycafloriCsoallactiinonu,shseurpmpiotrtcsratbsh,e Bab2a0,(SKp.eci1a9l82n.umGbaelrat2)h:ei2d6s6-a28n0d.pagurids of the Palau Islands
viewthatthis smallislandisadistinctbiogeographicprovince (Crustacea, Anomura). Proceedings of the Japanese Society of
withintheIndo-WestPacificregion. SystematicZoology23:57-70.
Baba,K. 1991.CrustaceaDecapoda:Alainiusgen.nov.,Leiogalathea
Acknowledgements Baba, 1969,andPhylladiorhynchusBaba, 1969(Galatheidae)from
New Caledonia. In: Crosnier, A. (ed.). Resultats des campagnes
Wwoerka:reNg.raNtegfoucl-tHoosefvaecriallitcaotleldeaagcuceesssfotrothMeiNrHheNlpcdoulrleicntgiotnhsi;s dM'UHiSstOoRirSeTnaOtuMr,elleV,oPlaurmise(A9). 1M5e2:mo4i7r9e-4s91d.u Museum national
.
Calcinusfrom EasterIsland 97
Briggs, J.C. 1974. Marine zoogeography. McGraw-Hill; New York. Morgan,G.J. 1991.AreviewofthehermitcrabgenusCalcinusDana
475pp. (Cmstaeea: Deeapoda: Diogenidae) fromAustralia, with deserip-
Chilton,C.1911.TheCrustaceaoftheKermadecIslands.Transactions tionoftwonewspeeies.InvertebrateTaxonomy5: 869-913.
andProceedingsoftheNewZealandInstitute43: 544-573. Nomura, K., Kamezaki, N., Hamano, T., and Misaki, H. 1988. The
DiSalvo,L.H.,Randall,J.E.,andCea,A. 1988.Eeologiealreeonnais- guidebookofmarineanimalsandplantsofOkinawa. Volume8-
sanee of the Eastern Island sublittoral marine environment. Crustacea(MacruraandAnomura). SouthernPress:Okinawa.232
NationalGeographicResearch4(4):451-473. pp.(inJapanese).
Eorest,J.1958.LesPaguresduViet-Nam.II-Surquelquesespecesdu Poupin,J. 1996.CmstaeeaDeeapodaofTrenchPolynesia(Astaeidea,
gem'e Calcinus Dana. Bulletin du Museum national d'Histoire Palinuridea, Anomura, Braehyura). Atoll Research Bulletin 442;
naturelle(2)30(2-3); 184-190,285-290. 1-114.
Eorest, J., and McLaughlin, P.A. 2000. The marine fauna of New Poupin,J. 1997.LespaguresdugenreCalcinusenPolynesiefran§aise,
Zealand; Paguridae (Deeapoda: Anomura) exelusive of the avee le deseription de trois nouvelles especes (Cmstaeea,
Lithodidae.SuperfamilyCoenobitoidae.NationalInstituteofWater Deeapoda,Diogenidae).Zoosystema 19(4);683-719.
andAtmosphericresearchBiodiversityMemoir114: 31-103. Poupin,J.,andMcLaughlin,P. 1998.AdditionalCalcinus(Deeapoda,
Eorest, J., SaintLaurentde,M., McLaughlin, P.A., andLemaitre, R. Anomura, Diogenidae) from Ereneh Polynesia with three new
2000. The marine fauna ofNew Zealand: Paguridae (Deeapoda: speeies and a key to Indo-West Pacific species. Crustacean
Anomura)exelusiveoftheLithodidae.NationalInstituteofWater Research27: 9-21
andAtmosphericresearchBiodiversityMemoir114: 1-250. Rahayu,D.L.,andEorest,J. 1999. SurlestatutdeCalcinusgaimardii
Gherardi,E, andMeLaughin,P.A. 1994. Shallow-waterhermitcrabs (H. Milne Edwards, 1848) (Deeapoda, Anomura, Diogenidae) et
(Cmstacea: Deeapoda: Anomura: Paguridae) from Mauritius and deseriptiondedeuxespecesnouvellesapparentees.Zoosystema21
Rodrigues islands, with the description of a new speeies of (3):461^72.
Calcinus.RafflesBulletinofZoology42(3):613-656. Randall,J.E. 1998. ZoogeographyofshorefishesoftheIndo-Paeific
Grant, E.E., and McCulloch, A.R. 1907. Deeapoda Cmstacea from region.ZoologicalStudies37(4):227-268.
NorfolkIsland. ProceedingsoftheLinneanSocietyofNewSouth Randall,J.E.1999.ReportonfishcolleetionsfromthePiteairnIslands.
Wales32: 151-156. AtollResearchBulletin461: 1-36.
Haig, J. 1974. Calcinuspascuensis, a new hermit erab from Easter Rehder,H.1980.ThemarinemollusksofEasterIsland(IsladePascua)
Island (Deeapoda, Anomura, Diogenidae). Crustaceana 27 (1): and Sala y Gomez. Smithsonian Contribution to Zoology 289;
27-30. 1-167.
Haig, J., and McLaughlin, P.A. 1984. New Calcinus species Retamal,M.A. 1981. Catalogoilustradodeloscmstaeeosdeeapodos
(Deeapoda,Anomura,Diogenidae)fromHawaii,withakeytothe de Chile. Guyana Zoologica, Universidad de Coneepcion 44;
loealspecies.Micronesica 19(1-2): 107-121. 1-110.
Hoover,J. 1998.Hawaii'sseacreatures.AguidetoHawai'i'smarine Shih,H.T 1998.TheCalcinushermitcrabsofTaiwan. TaiwanNatural
invertebrates. MutualPublishing;Honolulu.366pp. Science59: 82-94(inChinese).
Kato, S., andOkuno, J. 2001. ShrimpsandcrabsofHachijoIsland. Shih,H.T,andLee,S.C. 1997.Identityoftwohermiterabs,Calcinus
TBS-BritannieaCo.,Ltd:Tokyo. 157pp. vachoniEorest, 1958,andCalcinusseuratiEorest, 1951,fromthe
Lemaitre, R. 1998. Revisiting Tylaspis anomala Henderson, 1885 coralreefsofTaiwan(Cmstacea,Deeapoda,Anomura).Journalof
(Parapaguridae),witheommentsonitsrelationshipsandevolution. theTaiwanMuseum50(1):21-31.
Zoosysterna20(2):289-305. Takeda, M. 1994. Eield Books 9. Cmstaceans. Pp. 191-232 in:
Lewinsohn, C. 1982. ResearehesontheeoastofSomalia. The shore Okutani,T.(ed.).Animallifeoncoralreefs.Yama-Kei:Tokyo.319
and the dune of Sar Uanle. Diogenidae, Paguridae and pp.(inJapanese).
Coenobitidae (Crustacea Deeapoda Paguridae). Monitore Tudge,C.C. 1995.Hermitcrabsofthegreatbarrierreefandcoastal
ZoologicoItaliano, Supplernento 16:35-68. Queensland. SchoolofMarineSeienee,UniversityofQueensland,
Matsuzawa, K. 1977. Sea shore animals ofMuroto. Committee for BaekhuysPublishers:Leiden.40pp.
PublieationofseashoreanimalsofMuroto,pagesunnumbered,pis Whitelegge,T.1901.Deseriptionofanewhermitcrab{Calcinusimpe-
1-126(inJapanese). rialis),fromLordHoweIsland.RecordsoftheAustralianMuseum
Miyake, S. 1983. in: Utinomi (ed.). The aquatic lower animals of 4:48-51.
Japan. Gakken illustrated nature encyclopedia, Gakken Co Ltd; Wooster,D.S.1984.ThegenusCalcinus(Paguridae,Diogenidae)from
Tokyo(firstpublished 1975).342pp.(inJapanese). the MarianaIslands ineluding three new species. Micronesica 18
Morgan, G.J. 1990. A eolleetion of Thalassinidea, Anomura and (2): 121-162.
Braehyura (Cmstaeea, Deeapoda) from the Kimberley region of
northwesternAustralia.ZoologischeVerhandelingen265: 1-90.