A New Genus And New Species Of Crab Of The Family Xanthidae Macleay, 1838 (Crustacea : Decapoda : Brachyura) From The Southwestern Gulf Of Mexico

2004·3.1 MB·English

by  A Gracia

PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
117(4):505-513.2004.
Anewgenusandnewspeciesofcrab ofthefamilyXanthidae
MacLeay, 1838 (Crustacea: Decapoda: Brachyura) fromthe
southwesternGulfofMexico
AnaRosaVazquez-BaderandAdolfoGracia
(ARVB),(AG)InstitutedeCienciasdelMaryLimnologfa,UNAM,Apdo.Postal70-305,
Mexico,D.F.,04510,Mexico,e-mail:[email protected];[email protected]
Abstract.—AnewgenusandnewspeciesbelongingtotheEuxanthinaesub-
family, Batodaeus adanad, are described from the southwestern part ofthe
GulfofMexico.WhereasthenewgenusissimilartoMonodaeusGuinot,1967
inthecarapaceornamentationandshapeofpereopods,itdiffersinthestructure
ofthe abdomen and maletelson, sternoabdominalcavity, and shape andor-
namentation—ofthefirstgonopod.
Resumen. Sedescribeunnuevogeneroyunanuevaespecieperteneciente
alasubfamiliaEuxanthinae,paraelsuroestedelGolfodeMexico.Estegenero
nuevoessimilaraMonodaeusGuinot, 1967,enlaornamentaciondelcapar-
azonyformadelospereopodos; sinembargo, difieredeesteenlaformay
tamanodelabdomen,telsonycavidadesterno-abdominal,asicomoenlaes-
tructuradelosapendicessexuales.
Inthecourseofdeep-waterbiodiversity UNAM (CNCR). Measurements listedare
surveysintheCayoAreasandwestsideof inmillimeters (mm): total carapacelength
Triangulos inthe southwesternpartofthe (CL)andcarapacewidth(CW).
GulfofMexico, specimens ofan unusual
speciesofxanthidcrabwereobtained.Al- Batodaeus,newgenus
though superficially similar to species of —
MonodaeusGuinot,1967,theypossesssev- Diagnosis. Carapace subhexagonal,
eral atypical features that suggest other- broader than long; dorsal surface convex
wise.Theyareheredescribedasanewge- and granulated. Regions in male well de-
nusandnewspecies. marcated especially in the anterior half,
front strongly deflexed; innerorbital teeth
MaterialandMethods conspicuous; thoracic sternumrelatively
narrow.Anterolateralmarginsarmedwith4
Specimenswerecollectedin1998during teeth(excludingouterorbitaltooth), sube-
surveys investigating the marine fauna in qualinsizetoposterolateralmargins;pos-
the deep southwestern Gulf of Mexico, teriormarginofepistometriangular,median
cruiseBATO(BiotadelosArrecifes,dela partdepressed,withdistinctmedianfissure,
Plataforma y Talud continental en el no- andapairofshallowbutclearlyvisiblelat-
roestedelBancodeCampeche),carriedout eral notches; preorbital and postorbital
onboardtheRA^JustoSierrabytheInsti- lobes conspicuous, granulated. Incomplete
tute de Ciencias del Mar y Limnologfa, endostomialridgespresent. Basalantennal
UNAM.Thesampleswerecaughtusinga segmentlong,subcylindrical,almosttouch-
semicommercialottertrawl. ing front, not filling space between front
Thematerialwasdepositedintherefer- andinnerorbitalteeth;asmallgapbetween
encecollectionoftheInstitutodeBiologia, basalantennalsegmentandsuborbitalmar-
PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
gin. Third maxillipeds not filling buccal ity and merus with prominent distolateral
cavity; merus with deep, rounded depres- angle;andthoracicsternite4withamedian
sionnearmesialmargin.Alongitudinaltu- longitudinalfurrow.However,thecarapace
berculatedridgejustbelowsutureseparat- ofBatodaeus is more convex and the re-
ing subhepatic and subterygostomian re- gions are less well demarcated and with
gions. Pereopods 2-5 long, slender, with acutespines,particularlyonthehepaticre-
conspicuous spines on upper margin of gion; the posterolateral margins are sube-
merus andcarpus. Sternoabdominalcavity qualinlengthtotheanterolateral;thefront
relativelynarrowanddeep;thoracicsternite ismore advanced,withadeepsulcus;the
4 with median part slightly raised, with preorbitallobeisconspicuous;thesternoab-
short longitudinal furrow. Abdomen long, dominalcavityisrelativelydeeperandnar-
completelycoveringsternoabdominalcavi- rower;thoracicsternite4hasashallowbut
ty. Secondabdominalsegmentineachsex distinctlongitudinalmedianfurrow;theab-
notreachingcoxaeoffifthpereopod,leav- domenisrelativelynarrowandlonger;and
ing a small portion of sternite 8 visible. thefirstmalegonopodislong,slenderand
Sternite7coveringpartofpenisgrooveon slightly incurvedwith few spines, not se-
sternite8.Firstgonopodslender,slightlyin- toseorstoutasinMonodaeus.
curved;arowofspinesonmesialmargin. The bathymetric and geographic distri-
Second gonopod very short, sigmoid, ter- butionofthesetwogeneraisalsodifferent.
minal process curved with short setae on Monodaeus (type species Xantho couchii
distalend. — Bell, 1851) at present contains eight spe-
Type species. Batodaeus adanad, new cies: M. amaudi Guinot & Macpherson,
speGceinesd,erb.y—prM—eassecnutlidnees.ignation. l1a9t8u8s;GuMi.noctou&chMiaicp(Bheelrls,on1,8511)9;88M;.M.crgiusitnu--
Etymology. Thenameisacombination otae Forest, 1972; M. pettersoni Garth,
of Bato, the name of the cruise during 1985; M. rectifrons (Crosnier, 1967); M.
whichitwascollected,and "daeus" toin- rouxi(Capart, 1851);andM. tuberculidens
dicateits similarity withthegenusMono- (Rathbun, 1911). They all occur in the
daeus. — WesternIndianOcean,theEasternAtlantic,
Remarks. The taxonomic position of theMediterraneanSeaandtheEasternPa-
Batodaeusisuncertain.Althoughthespec- cific, from 20 to 500 meters. Batodaeus
imensstudiedheresharesomecharacteris- adanad, however, was collected in the
ticswiththesubfamilyActaeinaeinhaving Western Atlantic at depths from 160 to
sternite4withalongitudinalfurrowandthe 250m.
maleabdomenwithlockingmechanismon In comparison with Medaeops Guinot,
sternite 5, they also share some features 1967(onlyknownfromtheIndo-WestPa-
withtheXanthinaeinhavingthecarapace cific),Batodaeushasacarapacewhichhas
withfourteethandwiththoracicsternite4 theregionslessinflated,themerusofthird
being rather long (see Serene, 1984). In maxillipedwithaprominentdistolateralan-
fact,Batodaeusmorecloselyresemblesthe gle; the pereopods are more slender and
euxanthinid genus Monodaeus Guinot, longer,thethoracicsternumisnotflat;and
1967inthefollowingcharacters:regionsof thefirstmalegonopodlackssetae.Itdiffers
the carapace well demarcated; hepatic re- fromthesuperficiallysimilarIndo-WestPa-
gioninflated;presenceoffouranterolateral cific genus Alainodaeus Davie, 1992 in
teeth; surface of carapace with several having acarapace which is subhexagonal,
stronggranules;basalantennalsegmentjust not ovoid; a straight frontal margin; a
touchingthefront;anteriorborderofbuccal roundedtelson (triangularinAlainodaeus)
cavitywithaconspicuouscrest;thirdmax- andanalmoststraightfirstmalegonopod.
illipedsnotcompletelyclosingbuccalcav- Batodaeus,forthemoment,istentatively
VOLUME117,NUMBER4
placedintheEuxanthinae,asitseemstofit ulated.Posterolateralandposteriormargins
thereconsidering theprimarycharacterof of carapace almost straight, granulated.
thesubfamilystatedbySerene(1984):the Pterygostomian region (Figs. 2A, 4C)
formoftheanterolateralmarginwhichhas denselygranulated,withalongitudinal,spi-
the anterior part gradually sloping down- nose crest just below suture that divides
wardsviasubhepaticregiontomeetthein- subhepatic andpterygostomianregions;
fraorbital margin. The similaritytoMono- pterygostomianridgespresent,markedwith
daeusconfirmsthatitcanbeplacedasEux- smalltubercles.
anthinae,eventhoughthesubfamilyisnow Orbits%aswideasfront,separatedfrom
poorlydefined. itby adeep,longnotch,bordersconspic-
uouslydentate;2largesuturesonsupraor-
Batodaeusadanad,newspecies bitalregion;preorbitalandpostorbitallobes
Figs. 1-4 dentate.Anacutegranulatedtoothoninfra-
— orbital angle. Eyestalks completely fitting
CNMCatRer(i2a1l023e)x,am1i6.n6edm.mHXol2o3t.2ypmem:;1Sta6. innuloersbiatnsdwshteifnfsreettarea.cted,with4sharpspi-
9, 22°17.19'N, 91°43.08'W (Banco de Antennules (Figs. 2A, 4C) with basal
MC1a1a.my8pem1c9mh9e9,.XAolf1lf6o.t6Cyapmyem:o,1ArSet?an.aCs9)N,,C2R225°11(72.2m15,90'92N)3,, tslioenmggamitetenudtainndcaolnulsctiridemseatrtaoebflsysemgiamnlfellnatgtserda,nsluealnendsde;r.wpietnhul-a
A9?r1e°Cn4aN3s.)C0,R82'5W(12(1Bm0a2,4n)2c,3odM1e2a.C1yamm1p9me99c.hXeP,a1ro7af.tf6ypCmea:my,o1 mwietnBhtass4almsohbaairnlptee,snpnlianolunlgeessre;gtsmheeacnnotnbrdsoutabodc;fyolfuilrnatdgrheilscleauglm-,
offSta.8,22°13.72'N,9r46.64'W(Banco long.
dMeayCam19p9e9c.he,—offCayoArenas),162m,23 lonIgsecrhituhmanobfrotahdi;rdoumtaexrilsluirpfeadce(wFiigt.hm2eB-)
Description. Carapace (Fig. lA) sub- dian longitudinal furrow. Merus subquad-
htehaxnagloonnagl;,daobrosaults1u.r4fatcoe1c.o5nvteixm,esgrbarnoualdaetr- rate,outersurfacecoarselygranulated,me-
ed,granulescoarse,moreabundantonan- sialmargindentate,setose;distolateralan-
tsepraorlsaetersahloratndseptoaseteornolaftreorntaall,mahregpiantsi,cwaintdh tgelreioernlyd.ingPailnpamsaermgiiancaultleylosbeet,osdei.recEtxeodpaond-
protogastricregions. Regionsinmalewell reachingtotipofdistolateralangleofmer-
demarcated,especiallyintheanteriorhalf; us.
orbitalregionwithsmall,acutespines;he- Leftchelipedshorterthanrightandmore
patic region inflated, with 3-4 rows of spinose(Figs.4A-B);merusgranulose,up-
spines; a depression between cardiac and perandlowermarginsdelimitedby arow
gastricregion;mesoandurogastricregions ofstrong,acute,inwardspines;outersurface
lessgranulated;frontstraight,stronglyde- ofcarpusspinose,innermarginarmedprox-
flexed; margin dentate, atmost% as long imally with strong acute spine curving in-
asCW, separatedfromprotogastricregion wards,junctionbetweencarpusandchelae
byalongtransversefurrow.Deepnotchbe- fringed with setae, inner surface densely
tweenfrontalandpreorbitallobes,thelatter granulated.Palmoflongchelawith3upper
strongly granulated. Anterolateral margins rows ofacute spines directed inwards, di-
armedwith4teeth(excludingtheouteror- minishinginnumberandsizetowardslower
bital),firstsmall,withmarginsgranulated, margin,innersurfaceslightlypunctate.Dac-
secondandthirdlongest,subequalinsize, tylusaboutaslongaspalm;fingersleaving
spinoseanddirectedanteriorly,fourthbig- smallgapwhenclosed,eachterminatingin
gerthanfirst,withbordersandbasegran- inwardly curved corneous claw; movable
PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
Fig.L Batodaeusadanad,newgenus,newspecies.A.Holotypemale16.6mmX23.2mm(CNCR21023):
i.Allotypefemale11.8mmX 16.6mm(CNCR22509),dorsalview.
—
.
VOLUME117,NUMBER4
A
a^»*^»tT^>X-«^;f'*'"^^^C??Xnl
/* ^^_^4^V
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r^(' ' -v1
\<97^m>&f\ c^J
^ S7
Fig 2 Batodaeus adcmad A-C holotypemale.A,antennal,pterygostomian suborbital andcpistomal
regions,B,thirdleftmaxilliped outerview;C,stemoabdominalcavity.D allotypetcmdlc stcrnodbdominal
cavity Abbreviations g2,gonopod2,si-8,sternites1-8.
part with upper margin armed with small 4-5and5-6interruptedmedially;6-7and
acutespines,cuttingedgeswithbluntteeth. 7-8complete.Sternite4withslightlyraised
Pereopods 2-5, slender, subequal in medianpart,withshortlongitudinalfurrow.
length;pereopod4slightlylong,andpereo- Locking mechanismon sternite 5justbe-
pod2slightlyshort;allsegmentswithlat- low suture 4—5. Stemoabdominal cavity
eral and mesial faces spinose, coveredby deepandrelativelynarrow.
dense, thin setae. Dactylus slightly longer Maleabdomen(Fig.3A)withshortmar-
than propodus, terminating in corneous ginal setae on segments 1-6 and telson.
claw.Propoduswithlongthinsetaeonup- Firstsegmentlong,slender.Secondaslong
per border, outer surface punctate. Upper asfirst,broadest,notreachingcoxaoffifth
border of carpus with 4-6 small spines. pereopod, with small portion ofsternite 8
Merus with 12 spines on upper border, visible (Fig. 3B). Third to fifth segments
whichdiminishinsizeproximally,directed fused, punctate, longer than broad. Sixth
anteriorly. segmentaslongasbroad.Posteriormargin
Thoracicsternuminmale(Fig. 2C)rel- of telson rounded. Male sexual openings
atively narrow, densely granulated; sternal coxal.
sutures 1-2 indistinct, 2-3 complete, 3-4 Firstgonopod(Fig. 3C,D)long,reach-
incompleteandconfinedtolateralregions; ingbeyondsutureseparatingsternites4and
PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
I
Fig.3. Batodaeusadanad.A-E,holotypemale.A,abdominalsegments;B,abdommalsegments1
5andsternite8;C,gonopod1;D,tipofgonopod1;E,gonopod2.F,allotypefemale,abdommals:
Abbreviations:al-2,abdominalsegments1and2;ex5,coxa5;ep7,episternite7.
5,wheninsitu,slenderandwithdistalpart slender,extendingpastedgeoftelson;gon-
slightly incurved. Second gonopod (Fig. oporessmall,ov—ate.
3E)veryshort,curved,tipsharp,recurved. Colorinlife. Cream,withtipofchelae
Femaleswithregionsofcarapacelessde- fingersdark. —
marcated(Fig. IB);frontstraight,lessde- Etymology. This species name is
flexed;rightchelipedlongerthanleft,palm formed from an arbitrary combination of
with less conspicuous spines, pereopods the two first letters ofeach ofour sons'
moresetose,withoutspinesonupperborder names:Adolfo,Andres,andAdrian,andis
ofmerus, carpus with spines more acute. usedasanoun—inapposition.
Thoracic sternum (Fig. 2D) with longitu- Distribution. Western Atlantic; south-
dinalfurrowonsternite4lessmarked;ab- western GulfofMexico; Banco de Cam-
dominalcavitylessdeepandbroad;inlon- peche. —
gestspecimen,lockingmechanismonster- Remarks. Theshapeandornamentation
nite5notvisible.Abdomen(Fig.3F),with ofcarapaceandpereopodsofB.adanadare
firstandsecondsegmentsasinmale,leav- superficiallysimilartothespeciesofMon-
ingvisibleasmallportionofsternite8;seg- odaeus, notablyM. rouxi. Also,theptery-
ments 3-6freeandsubequalin size; pos- gostomialregionisdenselygranulatedand
teriorpartoftelsonrounded.Pleopodslong. the incomplete endostomial ridges of B.
VOLUME117,NUMBER4
IP^^
Fig.4. Batodaeusadanad,holotypemale.A,rightchela;B,leftchela;C,ventralviewofanteriorpartof
carapace.
512 PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
adanadaresimilartothoseseeninM.tub- loan ofspecimens during our visit to the
erculidensandM.couchii.Themorphology SmithsonianInstitution. Specialthanksare
ofthemerusofthethirdmaxillipedofB. giventoDr.MichelHendrickxforhiskind
adanadalsoresemblesthoseofM.guinotae review and valuable suggestions on the
andM. tuberculidens. manuscript. The comments of Dr. P. Ng
However, Batodaeus adanad is easily greatlyimprovedthequalityofthemanu-
separated from all Monodaeus species in script. We thank the crew and scientific
thattheformerhastheposterolateralmar- staffofR/VJustoSierraforfieldworkdur-
ginalmostaslongastheanterolateral,the ingcruiseBATO.WealsothankAnaElena
chelipeds are less stout, spinose, and are ViniegrafordrawingsandAnaIsabelBie-
coveredby strong tubercles; the sternoab- lerfortakingthephotographs.
dominal cavity is deeper and with a less
marked longitudinal furrow on sternite 4. LiteratureCited
The abdomen ofBatodaeus is long, com-
pletelycoveringthesternoabdominalcavi- Capart,A.1951.CrustacesDecapodesBrachyoures.In
tdfnyuoo,ramrbweodhnweormodeinoanesasstleinrnconaitMvtieoctnoy4m,oepdxllaepeeaotuvseieslndyg;scpatoehvcleieoerpnsegtirhtteehuoedpsiotanedbars-l- Couch,eEC(ox1aR9rpu.ne4xwdQ8ai.-clto1lit1.o9i8n—4e5r91eT.)Osrc—aNeBnaoarsftnuraiioxcccetgealiriloanoenpefssshia3oq(df1Cuere):uPI1se'tb1nAae-ztci2aleg0naae5ncn.te,idqaNuNneaestwuSrluatedlos
2-5 without a granulated crest on the su- HistorySociety:13-14.
periorborder ofmerus; and the telson of Crosnier,A.1967.RemarquessurquelquesCrustaces
omgayleofistrhoeunfidrestd.goInnoapdodditiionn,B.thaedamnoarpdhdoilf-- dDtiaeoecnuaspdoerdeecHtseitfbreeornnotshpsiapqn.uoenpsoevo.ua—ecsatBn-uatlfhlreoitcciaanirnpdsuu.sMDeuestscerMiuepm--
fers from that in any known Monodaeus nationald'Histoirenaturelle,Paris,(2),39(2):
species. 320-344.
ThenewspeciesdiffersfromMedaeops Davie,PJ.F 1992.DeepwaterXanthidcrabsfrom
edwardsi Guinot, 1967, M. neglectus Fthroeindceha).Po—lyBnuelslieati(nCrudstuaceaM,usDeecuampodan,atiXoanna-l
(Balss, 1922),andM. granulous(Haswell, d'Histoirenaturelle,Paris,4'-".sen, 14,section
1882) inthatallthesespecieshavealess A,n22:501-561.
convex carapace, with the regions hardly Drach,P.,&J.Forest.1953.Description—etrepartition
projecting;theirpereopodsareshorterand desXanthodesmersd'Europe. Archivesde
basrrteoeargdnreuarmn;,ulaaantndedd.tshteTehrfeninogfaiebrrsdstomgoiofnnatohlpeoicdra,vcihttehylo,irpatecodios,c Forest,ZgeJuoa.iounl1xo9ot7ga2bi.eaetUhespynx.apelenereosisvmp.eed—nceteTahlnMaeoeludeavitsetslgeielranereaJrdnuaeelg:eoX,salnM9at0ovh(ni1ico)da:daa1e8-e(d31ue5)ss.:
arealsodifferentinmorphology. 63-69.
Batodaeusadanadcanbeeasilyseparat- Garth,J.S.1985.Onasmallcollectionofbrachyuran
aedndfAr.omriAmlaatiarnaodDaaevuise,ak1i9ak9i2Dinavtihea,tt1h9o9s2e CESrcxrupiseptdpiastcieIoannstfoirtfoumt1i9o5En8a.sotf—eOrOcceIcsaalnsaoingodrnaaoplbthPayaipnDeeodrwsnbowyfittnhhdee
specieshaveacarapacethatistransversally AllanHancockFoundation(3):1-12.
ovoid;thefrontislessdeflexed;thecheli- Guinot, D. 1967. Recherches preliminaires sur les
pptheoeddssiasercesotnomduotrmewailrteohbusgsltoi;nghottphleyodftiwriisststmemadoldeteirpg;aotanenol-dy gySsorteuoiurummeppses.nmoatenIinIo.etntsaLlMneeadstd'uHaraieenslutcssoiiecrnDhesaenznaagt.leuen—srreeClBslrueul,slMtePiatacicrnreisso,dpBua3r9naM(oc2uph)-e-:
longer. 354-374.
,&E.Macpherson. 1988.Remarquessurle
Acknowledgments gDsceerncirapetpiooMdnoandoeBdrdaaeecuhuxysuersGapu)ei.cn—eostB,unlol1ue9vt6ei7ln,ledsauv(eCcMruuslsateacdueem-a
Dr.RafaelLemaitreandDr.JaniceClark nationald'Histotoirenaturelle,Paris4^sen,10:
are greatly appreciated for their help and 731-757.
VOLUME117,NUMBER4
MacLeay.W.S. 1838.Onthebrachyurousdecapod Serene,R.1984.CrustacesDecapodesBrachyouresde
CrustaceabroughtfromtheCapebyDr.Smith. rOceanIndienOccidentaletdelaMerRouge.
InIllustrationsoftheAnnulosaofSouthAfrica: Xanthoidea:XanthidaeetTrapeziidae.Avecun
beingaportionoftheobjectsofnaturalhistory Addendum—par Crosnier (A):Carpillidae et
chieflycollectedduringanexpeditionintothe Menippidae. FauneTropicale.OfficedelaRe-
interiorofSouthAfrica,underthedirectionof cherche ScientifiqueetTechnique Outre-Mer.
Dr.AndrewSmith,intheyears1834,1835,and Paris,24:1-400.
1836;fittedoutby"TheCapeofGoodHope
Association for Exploring Central Africa".
London:53-71. AssociateEditor:ChristopherBoyko