MemoirsofMuseumVictoria66: 117-127(2009) ISSN 1447-2546(Print) 1447-2554(On-line) http://museumvictoria.com.au/About/Books-and-Journals/Journals/Memoirs-of-Museum-Victoria The genus Floresorchestia (Amphipoda: Talitridae) on Cocos (Keeling) and Christmas Islands J.K. Lowry &R.T. Springthorpe CrustaceaSection,AustralianMuseum,6CollegeStreet,Sydney,NewSouthWales,2010,Australia(jim.lowry@austmus. gov.au&[email protected]) Abstract Lowry,J.K. & Springthorpe, R.T. 2009. The genus Floresorchestia (Amphipoda: Talitridae) on Cocos (Keeling) and ChristmasIslands.MemoirsofMuseumVictoria66: 117-127. ThewidespreadIndo-WestPacificandCaribbeantalitridgenusFloresorchestiaisreportedfromCocos(Keeling) andChristmasIslandsforthefirsttimeandanewspecies,F.pooreiisdescribed.Floresorchestiapooreiiscommononthe beachesofWestIsland,Cocos(Keeling). Keywords Crustacea,Amphipoda,Talitridae,Cocos(Keeling)Islands,ChristmasIsland,taxonomy,newspecies,Floresorchestia poorei Introduction area of investigation because this widespread Indo-West As partofthe Circum-AustralianAmphipodProject(CAAP) Pacific and Caribbean genus, with little means of dispersal, ateamofAustralianMuseumbiologists collectedextensively holdsanimportantbiogeography story. at Cocos (Keeling) Islands and Christmas Island during Location October 2008. Among the collections was a new species of Floresorchestia from sheltered sand beaches at Cocos Cocos(Keeling)isanisolatedatollinthenorth-easternIndian (Keeling) Islands. A small populationofFloresorchestiawas Ocean. Until the 1840’s it was forested and was the site ofa alsofoundatDollyBeachonChristmasIslandbutnomature huge seabird rookery. In the early 1800s the habitat was males were collected and we cannot describe it at this time. destroyedandreplacedwithCoconuttrees.Theonlyremaining TherearefewotherbeachesonChristmasIslandwithsuitable intact habitatinthis set ofislands is atNorth Keeling Island habitat.Atthetimeofitscollectionthepopulationwas small, about 20 km north ofCocos (Keeling). The islands ofCocos shelteringundercoconutsandrestrictedtotheedgesofasmall (Keeling) are ringed by white calcareous sand beaches. streaminthemiddleofDollybeach. Floresorchestiapooreiiscommoninthesupralittoralzoneon Floresorchestiaisawidespreadcoastalandforest-dwelling these beaches wherever suitable habitat occurs. We strongly genuswhichoccursmainlyonislandsintheIndianandPacific suspectFloresorchestiapooreiwasliving atCocos (Keeling) OceansandintheCaribbeanSea.Itisastraightforwardgenus beforethetransformation,butthereis apossibilitythatitwas torecognizebecauseoftheautapomorphicstridulatingorgans introduced with the Coconut plantations. If they were there on the epimera. Unfortunately early species such as F. beforethetransformationthenthey shouldbelivingonNorth pickeringi (Dana, 1853), F. floresiana (Weber, 1892), F. KeelingIsland. anomala (Chevreux, 1901) and F. ancheidos (K.H. Barnard, Micro-morphologyofFloresorchestia 1916) werenotwell describedinamodern sense andthis has leadto confusion in lateridentifications. Recently Miyamoto The maxillipedal palp in talitrids may be fully developed, &Morino(2008)haveproducedmoderndetaileddescriptions reduced to a small rectangular article, reduced to a button- whichreveal newly recognised species-level characters inthe shapedarticleorfusedtoarticle3ofthepalp.InFloresorchestia genus.Inthispaperwedescribeanewspecies,F.pooreifrom pooreiitisreducedintoabutton-shapedarticle(fig. 1C). Cocos(Keeling)Islandsandreportanundescribedpopulation The male gnathopod 1 andfemale gnathopod 2have well ofFloresorchestiafromChristmasIsland. developedlobes ontheposteriormarginofthemerus, carpus We think there are unrecognized species hidden in the and propodus (figs ID, H, J, 2D). These lobes are covered in synonymies ofF. anomala andF.floresiana. Wealso suspect short palmate setae (fig. 2E, F) of Oshel & Steele (1988: 96, thereareadditionalundiscoveredspeciesscatteredthroughout fig. 16). Palmate setae have a solid base radiating into short thenumerous Indo-WestPacificislands. This is animportant distaltinesandmaybeusedinraspingorscouring.Theytake 118 J.K.Lowry&R.T.Springthorpe Figure1.Floresorchestiapooreisp.nov.,A-B,paratype,female,AMP80543:leftmandible;B,leftmandibleincisor;C,paratype,female,AMP80543: AM maxillipedpalparticle4.D-J,paratype,male, P80544:malegnathopod1;E,propodusposterolateralserrateseta;F,propodusposterolateralserrate setae;G,palmanddactylusshowingcuspidatesetaealongpalm;H,memsshowingposteriorlobecoveredinpalmatesetae;I,propoduslateralcuspidate seta;J,carpusshowingposteriorlobecoveredinpalmatesetae.Scalebars:A,BandDrepresent100pm,Crepresents50pm. ThegenusFloresorchestia(Amphipoda:Talitridae)onCocos(Keeling)andChristmasIslands 119 Figure2.Floresorchestiapooreisp.nov.,A-C,gnathopod2,paratype,male,AMP80544:B,posteromedialmarginofpalmshowingattenuated AM dactylusfittingintogroovewithcuticularpatch;C,cuticularpatch.D-F,gnathopod2,paratype,female, P80543:E,smallpalmatesetaeon propodus;F,largepalmatesetaeonpropodus.Scalebars:AandDrepresent100pm. 120 J.K.Lowry&R.T.Springthorpe Figure3. Floresorchestiapooreisp. nov.,A-C,paratype,female,AMP80543:A,pereopod3 dactylus;B,pereopod4dactylus;C,denticulate patchondactylusofpereopod4;D-G,paratypefemale,AMP80532: D-E,spatulatesetaeonoostegiteofgnathopod2;F,stridulatingorganon epimera2and3,basisofpereopod7posteriormargin;G,telsonanduropod3.Scalebars:A,B,FandGrepresent100pm,Drepresents20pm. ThegenusFloresorchestia(Amphipoda:Talitridae)onCocos(Keeling)andChristmas Islands 121 slightly different forms depending on their position on the notched partially cleft orin the case ofF.poorei completely lobes. Whatever the function these lobes are widespread cleft (fig. 3G). Thetelson appears to be enclosedbythe sides within the talitrids. In males they are found on different ofurosomite3 andthepeduncleofuropod3. combinationsofthemerus,carpusandpropodusofgnathopod 1andinfemales,andmalesofanumberofland-hoppergenera, Materialandmethods theyOoncctuhreosnurgfnaacethoofpothde2.propodus of gnathopod 1 there are The descriptions were generated from a DELTA database least two types of sensory setae. Both of these setal types (Dallwitz2005)tothetalitridgeneraandspeciesoftheworld. appearto have pores atthe tips. Cuspidate setae occuralong All material is lodged in the Australian Museum, Sydney tIhI)e.pAalsmhor(fti,g.sl1eGn)dearn,dshoanrpthperloajteecrtailonanadrimseedsifarlosmurtfhaecesisde(fiogf. u(pApMe)r.liApb;brMeDv,iatmiaonndsibalree;: LAL,,alnotweenrnal;ip;G,MXg,namtahxoiplolda;; MUPL,, theshaftandarowofdenticlescoversthedistalend.Atthetip maxilliped;P,pereopod;pi,pleopod;T,telson;U,uropod;L, is adistinctpore. The posterolateral serrate setae (fig. IE, F) left;R,right. have a long, slender shaft with setules, distal denticles and a terminalpore,similartotheplumodenticulatesetaeofWatling TalitridaeRafinesque, 1815 (1989,22,fig.4E) andtheserratesetaeofGarm(2004,fig8a, FloresorchestiaBousfield, 1984 c). Onmale gnathopod2theanteriormarginofthebasis and OrchestiafloresianagroupBousfield, 1971:267. ischiumdeveloplateralandmedialflangeswhichformacradle Floresorchestia Bousfield, 1984: 205. —Miyamoto & Morino, forthe propodus (fig. 2A). The dactylus is distally attenuated 2008:838. and fits into a groove along the posteromedial margin ofthe propodus(fig.2B).Atthecornerofthepalmwherethegroove Type species. Orchestia floresiana Weber, 1892, original designation. begins thereis adistinctcuticularpatch oftiny denticles (fig. 2C). This patch forms an abrasive pad which may assist Included species. Floresorchestia includes 14 species: F. holding. ancheidos(K.H.Barnard,1916);F.anomala(Chevreux,1901); The cuspidate dactylus ofpereopod3 tapers evenly along F. anoquesana (Bousfield, 1971);F. anpingensisMiyamoto & itsmargin(fig.3A),butthedactylusofpereopod4isthickened Morino, 2008; F.floresiana (Weber, 1892); F. guadalupensis at the base and a distinct notch occurs along the posterior Ciavatti, 1989; F. hanoiensis Hou & Li, 2003; F. monospina margin (fig. 3B). Onthe anterodistal margin ofthe dactyli of (Stephensen, 1935); F. pectenispina (Bousfield, 1970); F. pereopods 3 and4there is a dense patch ofabout 20 rows of pickeringi (Dana, 1853); F. poorei sp. nov.; F. samoana whatappearstobetinydenticles(fig.3C).Thesepatchesoccur (Bousfield, 1971); F. vitilevana (J.L. Barnard, 1960); F. in othertalitrids and also onpereopods 5-7. A patch ofwhat yehyuensisMiyamoto&Morino,2008. appears to be spatulate setae is shown on the dactylus of pereopods 5 and 6 of Notorchestia naturaliste (Serejo & Description.Head.Mandibleleftlaciniamobilis 5-dentate or Lowry2008: 186,fig. 18).Thefunctionofthesepatchesisnot 4-dentate. Maxilliped palp article 2 distomedial lobe well known. developed,article4reduced,button-shaped. Among female talitrids three types of setae have been Pereon. Gnathopod 1 posterior margin ofmerus, carpus documented onthe oostegites: simple setae, curl-tipped setae and propodus each with lobe covered in palmate setae; palm and setae with multi-furcatetips. InFloresorchestiapoorei a transverse. Gnathopod 2 subchelate. Pereopods 2-4 coxae fourth type occurs. The long slender setae (fig. 3D) become widerthan deep. Pereopods 6-7 longerthan pereopods 3-5. splayed at the tip (fig. 3E) to form a spatulate locking Pereopod 6 posterior lobe inner view posteroventral corner mechanism. subquadrate or posteroventral corner rounded. Pereopod 7 Although ‘slits’ onthe epimeral plates ofFloresorchestia basis posterior margin with distinct minute serrations, each havebeenmentionedmanytimes,onlyBousfield(1970, 1971) withasmall seta. has everconsideredtheirfunction as stridulating organs. The Pleon. Pleopods all well developed. Pleopod 1 peduncle serrate posterior margin ofthe basis of pereopod 7 has also with or without sparse marginal setae. Pleopod 2 peduncle been mentioned many times, most recently by Miyamoto & withorwithoutsparsemarginalsetae;outerramuslongerthan Morino (2008). We have had aclose lookatthis morphology peduncle.Pleopod3pedunclewithorwithoutmarginalrobust (figs3F).Thesocalled ‘slits’ arerelativelycomplexstructures setae. Epimera 2-3 each with stridulating organsjust above with a raised anterior border and an immediately posterior ventral margins. Uropod 1 peduncle distolateral robust seta hollow bowl or slit. Bousfield (1970, 1971) referred to these present; innerramus with marginal robust setae; outerramus structuresasstridulatingridgesandweagreethattheseridges withoutmarginalrobustsetaeorwithonelongmidmedialseta formastridulatingorgan.Andthestridulatorappearstobethe (inmale). Uropod2notsexuallydimorphic; outerramuswith unique, strongly serrate posterior margin with tiny robust marginalrobustsetae. Uropod3ramus shorterthanpeduncle. setae onthe basis ofpereopod7. The interestingthing isthat Telsonwithmarginal andapicalrobustsetae. they occur on both sexes so the function is probably not to Female (sexually dimorphic characters). Gnathopod 1 attractamate. posteriormarginofmerus, carpus andpropodus eachwithout The telson in Floresorchestia may be entire, apically lobecoveredinpalmatesetae;palmslightlyacute. Gnathopod 122 J.K.Lowry&R.T. Springthorpe 2mitten-shaped. Type locality. Rumah Baru, West Island, Cocos (Keeling) Islands,IndianOcean(12°09'22"S96°49'41"E). Habitat. Supralittoral and terrestrial amphipods of tropical rain forests, mangroves and beaches in the Indo-West Pacific Etymology. Namedforour goodfriend Gary Poore inthanks andCaribbean. forhis help overthe years and in recognition ofhis immense contributiontothefieldofcarcinology. Remarks. Floresorchestia belongs to a group of Indo-West AM Pacific genera which includes Microrchestia Bousfield, 1984, Description. Based on holotype, ovigerous female, Platorchestia Bousfield, 1982, Protorchestia Bousfield, 1982, P80192. Sinorchestia Miyamoto & Morino, 1999 and Talorchestia Head.Eyelarge(greaterthan 1/3 headlength).Antenna1 Dana, 1853. They all share a 5 dentate left lacinia mobilis, short, rarely longer than article 4 of antenna 2 peduncle. subchelate male gnathopod 2, well developed pleopods and Antenna2uptohalfbodylength;pedunculararticlesnarrow; uropod 1 without marginal robust setae on the outer ramus article 5 longer than article 4. Mandible left lacinia mobilis (except Sinorchestia nipponensis which has marginal robust 5-dentate. Maxilliped palp article 2 distomedial lobe well setae on the outer ramus). Within the group Floresorchestia, developed,4reduced,button-shaped. Platorchestia, Sinorchestia and Talorchestia have Pereon. Gnathopod 1 sexually dimorphic; parachelate; cuspidactylate pereopods. Only Floresorchestia and coxa 1 smallerthancoxa2;posteriormarginofmerus,carpus Platorchestia have the reduced button-shaped fourth articles and propodus each without lobe covered in palmate setae, in on the palps ofthe maxilliped and distally attenuated dactyli male only; propodus subrectangular, propodus posterior on male second gnathopods. Both ofthese genera have wide marginwith3cuspidatesetaealongposteriormargin,propodus distributions. posteriormarginwith3 serrate setae along posteriormargin; Floresorchestia monospina (Stephensen, 1935) and F. palm acute, palm with 4 serrate setae; dactylus longer than pectenispina(Bousfield, 1970)differfromotherspeciesinthe palm. Gnathopod2 sexuallydimorphic;mitten-shaped; coxal genus in having a long, marginal slender robust seta with a gill simple or slightly lobate; basis anterior margin smooth, modifiedtip onthe outerramus ofmale uropod 1 (Bousfield basisexpandedproximally;ischiumwithoutposterodistallobe 1970). Floresorchestia hanoiensis Hou & Li, 2003, F. on medial surface; posterior margin of merus, carpus and malayensis (Tattersall, 1921), F. samoana (Bousfield, 1971) propoduseachwithlobecoveredinpalmatesetae;carpuswell andF.vitilevana(J.L.Barnard, 1960)differfromotherspecies developed (not enclosed by merus and propodus), posterior inthegenusinnothavingstridulatingorgansonepimera2and lobe present, projecting between merus and propodus; palm 3.InotherrespectsthesespeciesappeartobeFloresorchestia obtuse, smooth, not lined with robust setae, palm without andF. hanoiensishas pitting ontheface ofepimera 1 and 2. patchoftinydenticles atcornerofpalm; dactylus subequal in Floresorchestia pickeringi (Dana, 1853) needs to be lengthtopalm,notattenuateddistally;gillsimple,notincised. redescribedtoconfirmits statusinthe genus. Pereopods 2-4 coxae wider than deep. Pereopods 3-7 Floresorchestia ancheidos (K.H. Barnard, 1916), F. cuspidactylate. Pereopod 4 subequal or slightly shorter than anomala (Chevreux, 1901) and F.floresiana (Weber, 1892), pereopod 3; carpus significantly shorter than carpus of typespeciesofthegenus,areallpoorlydescribedspeciesand pereopod 3; dactylus thickened proximally with a notch F. anomala and F.floresiana are the source of questionable midway along the posterior margin. Pereopod 5 propodus synonymies from wide-ranging localities. These species also distinctly longer than carpus. Pereopods 6-7 longer than need to be redescribed based on new material fromthe type pereopods 3-5. Pereopod 6 not sexually dimorphic; slightly localitiesusingmoderncharactersasoutlinedbyMiyamoto& shorter than pereopod 7; posterior lobe inner view Morino (2008) before realistic distributionsforspecies inthe posteroventralcornerrounded,posteriormarginperpendicular genuscanbedetermined. to ventral margin, posterior lobe with ridge, posterior lobe with 1-2 marginal setae. Pereopod 7not sexually dimorphic; Floresorchestiapooreisp.nov. basislateralsulcusabsent,basisposteriormarginwithdistinct minute serrations, each with a small seta, posterodistal lobe (Figures 1-7) present, shallow, broadly rounded; distal articles (merus and Materialexamined.Holotype:IndianOcean,Cocos(Keeling)Islands, carpus) slender; merus posterior margin evenly rounded; WestIsland,RumahBaru,(12°09'22"S96°49'41"E),beachwrack,J.K. propodus setationwithoutlargedistaltuftofsetae. Oostegites LowryandK.B.Attwood,8Oct2008,(stnMIWA819),AMP80192 long(lengthgreaterthan2xwidth),longerthanwide,weakly (ovigPearroautsypfeesm:atlye,pe9Al.o2Mcamlmi)ty.,AMP80193(mAalMe,11.7mm);AMP801A9M4 setoPslee(o6n-.11Plseeotapeo)d,sseatlalewweiltlhdsepvaetluolpaetde.tiPpsl.eopod 1 peduncle (many specimensA);M P80532 (female); P80543 (female); with marginal slender setae; biramous, outer ramus shorter P80544(male); P80549(male). Other material: Indian Ocean, Cocos (Keeling) Islands, West thanpeduncle, innerramus subequal inlengthto outer; inner Island, Government House Beach, (12°05'04"S 96°52'54"E), sand ramus with 9 articles; outerramus with 6 articles. Pleopod2 beach,J.K. Lowry,L.E. HughesandK.B.Attwood,7Oct2008,(stn peduncle with marginal slender setae; biramous, innerramus MI WA780),AMP.80545 (many specimens). Indian Ocean, Cocos subequalinlengthtoouter,outerramusshorterthanpeduncle; (Keeling) Islands, West Island, beach near “Two Trees dive site”, inner ramus with 7 articles. Pleopod 3 peduncle without (12°05’04"S96°52'54"E),J.K.Lowry,L.E.HughesandK.B.Attwood, marginal setae. Pleopod3biramous,innerramus subequalin 7Oct2008,(stnMIWA779),AMP.80547(6males,7females). length to outer, outer ramus shorter than peduncle; rami ThegenusFloresorchestia(Amphipoda:Talitridae)onCocos(Keeling)andChristmasIslands 123 Figure4.Floresorchestiapooreisp.nov.,paratype,male, 11.7mm,AMP80193. multarticulate;innerramuswith6articles;outerramuswith6 on medial surface; posterior margin of merus, carpus and articles.Epimera2-3eachwithastridulatingorganjustabove propodus each withoutlobe covered in palmate setae; carpus ventralmargins.Epimera2 subequalinlengthto epimeron3, triangular,reduced(enclosedbymerusandpropodus),posterior with 27 ridges. Epimera 3 with 17 ridges, posterior margin lobe absent, not projecting between merus and propodus; smooth, without setae, posteroventral corner with small propodus subovate; propodus twice as long as wide; palm subacutetooth,ventralmarginwithoutrobustsetae. Uropod1 acute,linedwithrobustsetae;palmwithcuticularpatchoftiny not sexually dimorphic, peduncle with 8 robust setae, denticlesatcornerofpalm,posteromedial surfaceofpropodus distolateral robust seta small; with simple tip; inner ramus withgroove;dactyluslongerthanpalm,attenuateddistally. subequal in length to outer ramus, with 3 marginal robust Habitat. Living inthe supralittoral zone on shelteredbeaches setae; outer ramus without marginal robust setae. Uropod 2 underseaweedsanddebris. not sexually dimorphic; peduncle with 6 robust setae; inner ramus subequal in length to outer ramus, with 2 marginal Remarks. Floresorchestiapooreiis currently the only species robustsetae; 1 marginalrobustsetae. Uropod3pedunclewith inthegenuswithafullyclefttelson. 3 robust setae; ramus shorter than peduncle, ramus linear Distribution. North-Eastern Indian Ocean. Cocos (Keeling) (narrowing), with 2 marginal robust setae, with 4-5 apical Islands(currentstudy). setae. Telson longer than broad, completely cleft, with 5 marginal andapicalrobustsetaeperlobe. AM Acknowledgements Male(sexuallydimorphiccharacters). Basedonmale, P80193. Gnathopod 1 subchelate, posteriormargin ofmerus, ThankstotheCAAPteam,KateAttwood,LaurenHughesand carpus andpropodus eachwithlobecoveredinpalmate setae; Michael Stuckey forhelping to collectthe beach-hoppers; to propodussubtriangularwithwelldevelopedposterodistallobe, TaniaLaity,DepartmentoftheEnvironment,Water,Heritage anteriormargin with 3 groups ofrobust setae, lateral surface and the Arts (DEWHA) for funding the field work; to Sue with 2 cuspidate setae, posterolateral surface with 5 serrate Lindsey forthe SEM micrographs; to Anders Garm and Les setae, propodus posteriormargin without cuspidate or serrate Watling for advice on setal types; to Alan Myers, as always, setae along posterior margin; palm transverse, dactylus forhisinsightfulcomments;andtoJoTaylorforinvitingusto subequal in length to palm. Gnathopod 2 subchelate; basis contribute to this book celebrating 30 years of scholarly slightly expanded; ischiumdistal triangularposterodistal lobe researchbyGaryPoore. 124 J.K.Lowry&R.T.Springthorpe Figure5.Floresorchestiapooreisp.nov.,holotype,ovigerousfemale,9.2mm,AMP80192.Scalebars: H,Epl-3represent0.5mm,remainder represent0.2mm. ThegenusFloresorchestia(Amphipoda:Talitridae)onCocos(Keeling)andChristmasIslands 125 Figure6.Floresorchestiapooreisp.nov.,holotype,ovigerousfemale,9.2mm,AMP80192,paratype,male, 11.7mm,AMP80193. Scalebars represent0.5mm. 126 J.K.Lowry&R.T.Springthorpe Figure7. Floresorchestiapoorei sp. nov., holotype, ovigerousfemale, 9.2 mm,AMP80192. Scale bars: P5-7 represent 0.5 mm, remainder represent0.2mm.