30 September 1991 Memoirs ofIhe Museum ofVictoria 52(2): 299-310 (1991) ISSN 0814-1827 https://doi.org/10.24199/j.mmv.1991.52.07 GUERNEA IPILYA AND G. YAMMINYE, NEW SPECIES (CRUSTACEA: AMPHIPODA: DEXAMINIDAE), FROM THE GREAT BARRIER REEF, AUSTRALIA By James Darwin Thomas' and J. L. Barnard- ^-,NiH,Bd-1.63«, D^epart'mReenetfoFfouInndvaetritoebnr.atPeC)ZoBoolxog5y6,9,SmBiitghPsionneiaKneyI,nstFiltourtiidoan,,3W3a0s4h3i,ngUtSonA, DC. 20560, USA Abstract Thomas. J.D. and Barnard. J.L.. 1991. Guemea ipilya and G. yamminye, new species (Crustacea:Amphipoda: Dexaminidae).fromtheGreat BarrierReef.Australia. Memoirsof the Museum ofVictoria 52: 299-310. Amodern diagnosisofGuemea isgiven, itsspecieslisted with theirbiogeographical dis- tributions based on Barnard and Barnard (1983). Two species. Guemea ipilya and G. yamminye. aredescribed from rubble in shallowwaterontheGreat BarrierReef. Guemea ipilya differs from its sympatriot, G. endota. in: lack ofmid-dorsal spines on the urosome, with the side spines smaller; spinose telson; much longer and denser setae on article 2 of percopod 5:largerposteriorlobeofcoxa 5;shorteranteriorlobeofcoxa6;stouterantennae; lackofhumponurosomite 1;shortpereopod6;lackofmajorposteriorspinesonarticle6of pereopGods 3-4; and lack ofspineson rami offemale uropod 3. Guemeayamminyediffers from retieulatus in the lack of serrations on article 2 of pereopod 7 and the weaker envelopment ofarticle 6 by article 5 on pereopod 7. Introduction Article 4 of pereopod 5 not asymmetrically Two new species, Guemea ipilya and G. expanded. Uropod 2 shortened. yamminye, are described from rubble in Description. Cephalic lobes rounded. Eyes shallow-water on the Great Barrier Reef. Infor- present. Molar weakly to scarcely triturative; mation about Guemea is updated, with a list of rakers weak, sparse or absent; mandibular palp species and their important references, their absent; maxillae poorly setose, though inner distribution, including codes of distribution plateoftenwith medialsetae; innerplateofmax- found in Barnard and Barnard (1983). illiped small to ordinary, palp slightly reduced, 4-articulate. Gnathopods ordinary though Dexaminidae Leach palms occasionally subtransverse. Pereopods simple, pereopods 5-7 typical of subfamily. Prophliantinae Nicholls Uropod 2short;uropod3small,rami lanceolate. Guemea Chcvreux Telson deeply cleft. Gills narrow, ovate orellip- tical, on coxae 2-6; oostegites slender. HelleTia Norman. 1868: 418 [homonym, Isopoda] Sexual dimorphism. Body of male thinner and (type species, llelleria eoalila Norman, 1868, monotypy). more streamlined than in female, pleon Guemea Chevreux, 1887: 302 (r—eplacement enlarged, anterior coxae compacted; eyes name).—Stebbing, 1906: 521 [in part]. Ledoyer, enlarged; llagellum ofantenna 2 elongate, mul- 1982: 346 [valid subgenus]. tiarticulate; article I ofantenna 1, article 4 of Prinassus Hansen, 1888: 82 (type species Phnassus antenna 2 often swollen and brushy and often nordenskioldi Hansen, 1888. original designation) rugose; uropod 3 setose(onlyspinose in female). [valid subgenus]. Mouthparts occasionally degenerate in varying DexamonicaJ.L. Barnard, 1958: 130(type species, degree. Dexamonica reduncans J.L. Barnard, 1958, monotypy) [subgeneric synonym ofPrinassus]. Remarks. Ledoyer (1982) noted that the differ- HauslorinpsisSchellenberg, 1938a: 12(typespecies ences between Guemea and Haustoriopsis were Haustoriopsis retieulatus Schellenberg, 1938a, bridged by species described since 1938 and monotypy) [subgeneric synonym ofGuemea]. therefore reduced Haustoriopsis to subgeneric Diagnosis. Only urosomites 2-3 coalesced. Ar- level under Guemea. We now judge the differ- ticle 5 of pereopod 7 normally rectangular. ences between the twosubgenera tobeso insub- 299 300 J. D. THOMAS AND J. L. BARNARD stantial that Haustoriopsis must be submerged Guernea (Guernea) latipes Ledoyer, 1979 (= totally. petalocera ID of Ledoyer, 1973), Madagascar Identifying species in this genus is very diffi- [698]. cult. Many are poorly described and lack detail Guernea (Guernea) longicornis Ledover, about both sexes. Minor differences between 1982, Madagascar [698]. sexes are probably important and should be Guernea (Guernea) magnaphilostoma illustrated. For example, the mouthparts of Hirayama, 1985, S. Japan [395]. males in well known species differfrom those of Guernea (Guernea) melape J.L. Barnard, females but often male mouthparts are over- 1972a, southern Australia [780]. looked.Someofthecoxaeareunknownformost Guernea (Prianassus) nordenskioldi (Hansen, species. The precise microscopic appearance of 1888) (J.L. Barnard, 1970) (Just, 1980), amphi- thedorsalsurfaceoftheurosomeisunknownfor Atlantic and Mediterranean [354+]. many species. Almost nothing has been pub- Guernea (Prianassus) nullispina Hirayama, lished on intraspecific variation. 1985, S. Japan [395]. Variables. The following significant variations ReGdueSreane[a677(]G.uernea) petalocera Ruffo, 1959, occur in the genus: palp ofmaxilla 1 uniarticu- Guernea (Guernea) quadrispinosa Stephen- late (G. endota, etc.) or Particulate (normal); sen, 1944 (Bulycheva. 1957). Sea of Japan inner plate ofmaxilla 2 very short (G. timaru); [391]. inner plate of maxilliped short (G. gelane), or Guernea(Prianassus)rectocephala Hiravama. long (G. endota); article 4 ofpereopod 5 dilated 1985, S.Japan [395]. (pGe.reloaptiopdes)7 osrtronnogtly(G(.G.rerteitciuclualtautsu)s;)aorrtisclcear5celoyf Guernea (Prianassus) reduncans (J.L. (type and G. latipes) enveloping article 6; inner Barnard, 1958, 1970). warm-temperate Califor- rami of uropods 1-2 reduced (G. gelane, G. nia [373]. tumulosa); spinesonuropods 1-2 shortened (G. Guernea (Guernea) reticulatus (Schellenberg, rhomba, G. tumulosa). 1938), Bismarck Archipelago [595]. Distribution. Marine, cosmopolitan except for Guernea (Guernea) rhomba Griffiths, 1974, Antarctica, 0-255 m, 25 species. 1975, southern Africa [743]. Species. See J.L. Barnard (1966a, b, 1970); MaGduaegransecaar(G[u6e9r8]n.ea)spinicornisLedoyer, 1982, Barnard and Barnard (1983) for explanation of Guernea (Guernea) tenuipes Ledoyer, 1979. geographic codes cited in brackets; Bulvcheva Madagascar [698]. (1957); Fage (1933); Gurjanova (1951); Kara- Guernea (Prianassus) terelamina Hirayama, man (1973); Shoemaker (1930, 1955). 1985, S.Japan [395]. Guernea(Guernea)brevispinisLedoyer, 1982. Guernea (Guernea) timaru J.L. Barnard Madagascar [698]. 1972b, NE New Zealand [773]. Guernea (Guernea) coalita (Norman, 1968) Guernea (Prianassus) tomiokaensis (= laevis Chevreux 1887) (Chevreux and Fage. Hirayama. 1985, S. Japan [395]. w1a92r5m) E(.LiAntcloanltni,c,1M9e7d9)ite(rBerlalnaena-nSa[n3t5i2n]i., 1982) souGtuheerrnneaAfr(iGcuae,rnienaq)uitliunmouulsos[a743G1r]if.fiths, 1976. GuernSeWa (Guernea) endota J.L. Barnard, Guernea (Guernea) unchalka J. L. Barnard 1972a, Australia [787]. 1972a, SW Australia [787]. Guernea (Guernea) gelane J.L. Barnard, Guernea (Guernea) yamminye Thomas and B1a9rG7n2uaaer,rdnS,eEaheArues(itGnru,aelNrinEaea[t)7r8o1p]iicpaillyAaustTrhaloimaa[s633]a.nd CBaeryGnluaoernrdn,[e6ah6e5r]s.epiecni,esN,ElatervoipsicIaDl AoufstWraallkiaer[63139]0.4 Key to subgenera of Guernea Urosomite 1 with weak dorsal hump in both sexes Guernea Urosomite 1 with retrorse dorsal process in female, high keel in male Prinassus NEW SPECIES OF GVERNEA (AMPHIPODA) FROM THE GREAT BARRIER REEF 301 Guernea (Guernea) ipilya sp. nov. propodi with only 2-4 weaksetae, dactyls bear- ing one large inner tooth; posterior margins on Figures 1-4 (part) article 6 ofpereopods 3-4 minutely ridged; per- Materialexamined. 1 male. 2 females. 1 juvenile. eopod 4 like 3 but article 5 with 1 less spine, Holotype:Australia.Queensland,LizardIsland,2.5 article 4 with 1 less seta; epimeron 1 with enor- m,rubblesampleVnearLizard Head.J.D.Thomasand mous inward bending anteroventral lobe; uro- J. Clark. 31 Jan 1989, Museum of Victoria (NMV) pod 2 with 2 basofacial setae in tandem; uro- J20Pa4r9a4tv(pfeesm:alTeype lowciatlhity8.egNgsM,V1.9J920m4m9)5.(juvenile somite 1 naked ventrally. Oostegites: ofcoxa 2 "y/\ 1.67 mm); USNM 253716 (female "x'\ 2.30 half as long as basis of gnathopod 2, truncate mm). apically, slender, subrectangular, with 2 apical Additionalmaterial: Lizard Island,North Point, 13 setae, ofcoxae 3-4 similar but with additional m, 28 Jan 1989, rubble sample from vertical cliffand posteroventral seta, of coxa 5 similar, with 4 unconsolidated bottom. J.D. Thomas, 2 specimens. setae. Gills of coxae 2-5 large sacs, of coxa 6 Lizard Island. Mermaid Island, 1-2 m, 26 Jan 1989, smaller, absent on coxa 7. formalin wash ofrubble, J.D. Thomas, 1 female. Pleopods: ratio oflengths ofpeduncle, outer Diagnosis. Accessory flagellum absent; antenna and inner rami for pleopods 1-3 = 29:33:32, 23u(rnilgohtb)edorbu3t-t4hi(lcekf;t)mvaenrdyibwuelaakrtienectihs,orsspiwniethro2-w 2i5n:n2e8r:2r8a,mianfdor2p6l:e2o8p:o2d6:s a1r-t3icl=es7-o7f,o7u-t7e,r7a-n7d; absenton right,with 1 large, 1 vestigial spineon coupling spines 2; each peduncle with 2 setae. llreaefrtag,ceh,mionflglaeasrphyewxiatonhfdosuestteaep;rarpialntanete;er,pulnaoilbaperstoiofcfulmlaatoxewi,elrlaapleixp1 Egutaygmeo,longaym.eFdraofmtetrhteheAugsitarnatlilaiznaArbdogroidgicnraelatlianng- monsoons and thunderstorms. Noun in appo- with 1 spoutand 2setae; innerplateofmaxilla2 muchshorterandbroaderthanouterplate,bear- sition. ing 3 apicomedial marginal setae, outer plate Distribution. Australia, Great Barrier Reef, with medium, subtruncate apex, palp with 9 Lizard Island, 1-3 m, rubble. setae;innerplateofmaxillipedsmall,outerplate Relationship. Guernea ipilya differs from the rberaocahdinagsmbiudtdlleonogfepraltphaanrtigcnlaet3h;ogpnoadth1o;pcoodx2aas5 Asupsintersalioann tGh.eenudrootsaomien,: (w1)itlhactkheofsmiidde-dsoprisnaels with very large, lobuliform, rounded posterior smaller; (2) spinose telson; (3) much longerand lsaoretbtieac,eleaonn6teaerrltioioncrglaelto2eb,eoaforptniecrcleoesoxpa4o-6d5v5eosfwteiplgeliradle;eovpaeonltdoepr7eidoo,rf dpooefsnctsoeexrraios6er:tla(oe6b)oesnotfoaructtoiexcrlaea5n2;to(e5fn)npsaehero;ero(t7pe)rodlaan5ct;ke(ro4if)ohrlaulromgbeper bdarcotaydllfaorrgme;,ianrnteirclream5inooftuernovpeoldospi1n-g2aasrtlioclnega6s, omnajuorrospoosmtietreio1r;s(8p)insehsorotnpaerrtiecolpeo6do6f;p(e9)reloapckodosf outer,peduncleofuropod2with 2dorsalspines. 3-4;(10)lackofspinesonramioffemaleuropod fapoircmal(isnpcionnetseoxft orfamgienuosn);utreolpsoodnson1l-y21o.1ftsihmoerts m3.axTihlelraeea1r-e2aalnsodmmaaxniylldiipfefde.rences in mandible, mawsaerlagoknigrnuagssombsoreoodatodh:ulbyelpeirdmoouernrsdoaenldc3;rwesuittr,housprooomssitotemreiotv1eesnwt2ir-ta3hl pioninItnetrdsirf2af,meri6s,of8f,rou9m.roaptnhodedsA1u01s-ta2rb;aolvaiena,dnp(lG1u.2s)g(et1lh1ae)nveleorniyng (fused) of medium height, almost evenly spinulose rims ofthe urosome. rarbaoomuuintdoef8d-u1ra5onpdwoedasslko1p-si2entogulfepssohosertatecrhfi;oorarpwmiac(riadnls,csopnibtneeeaxsrtionongf poiIWtnetdsihf1af,evr2es,cf4o,rmo5pm,a6rt,he7ed,9Ao,uusrt1r0sapaleicnaidens1G2t..o omnellyaptehosien genus); cuticle (light microscopy, lOOOx) with from other parts of the world which: (1) lack arcuate orsemicircularscale-serrations in lines, humpsand large spineson the urosome;(2)lack variable. cusps on antenna 2; (3) have coxa 5 with large Description.Eyeswith deeppurplecoresin alco- well developed anterior lobe but a much larger hol; upper lip rounded-truncate below; right rounded posteriorlobe;(4)haveequallyextend- (l5acsimnailalm,o2billairgses)mtahlalnerleaftnd(6mloarrgee)w;eoauktleyrtpoloatteheodf oinbgliqruaem(iveorfsusutrroapnosdvsers1e-)2p;al(m5)sohnavtheegsnliagthhtol-y mspapaxoliumltslaaonf1dwg2instaehttah9eo;sppboiadnsesiss,sopmfaoglonptahat,pheomxpeowdiditah1lsc-ufssahpcae-psleidko,ef pMoadOdsua.rgansecwanspeGc.ielsataippepseabrusttdoifbfeervsermyaicnlolsyeitnotthhee 302 J. D. THOMAS AND J. L. BARNARD Figure 1.Guerneaipilya,witi.tnbutedfigures=holotypefemale"w", 1.99mm;x=female"x" 2 30mm Capital mpalUleleda,ftajnttteudeoecrpiftsopbicreilvanrerpes.afht(imapagMusl;ursrdl),eWeests,Jrt,creeerrupdfi;lruebeaorceobsedtnbodoI;rbmpeeteXavol;r,iotatsKwmtw;,;aioxl-o"cioutnultwhsnlieiacaurrl;tsdectes,Yand,sLobe,ifugnlitlllefaeeltif;bdtgt.e"uZru(r,srmMeest;tof)ooaeM.srlrt,eese:ftgtmBioao,tnfmebd;acoiaidbdpny,il;tesda;oCplr,ePlsc,ecatiolptm;xeeaerrf;sn,eroDffep,lo<foar"edtdrLeat;ecaetntncoReyeh,suld;,-pfuieGrmmgc,ou,iprgmeommnedleean;addtsciiShkaa,aoillnpmn-,dogadrrxl,"oorrwlHtiilehgairehhphttecr,ediaagslldheeeTtftttl.rIetteSeRflnieetsrgrnohe'tntoro NEW SPECIES OF GUERNEA (AMPHIPODA) FROM THE GREAT BARRIER REEF 303 Figure 2. Guernea ipilya, holotype female "w", 1.99 mm. 304 J. D. THOMAS AND J. L. BARNARD Figure 3. Guernea ipilya, holotype female "w", 1.99 mm. NEW SPECIES OF GUERNEA (AMPHIPODA) FROM THE GREAT BARRIER REEF 305 rFLiiogpwunerrree,44Guluelprnpnneeerar,yGuauwmemmrincneayaeii,/p/i»lh>voal,othyopleo,t>ym*paelfeemaal„e, "iw."o,z1m.m9.9mymj. f epfimera (\y showing anterior lobe of epimeron bent outward and flattened. 1 306 J. D. THOMAS AND J. L. BARNARD short apical spines on the rami of uropods 1- lobe weak and ragged; anterior lobe on coxa 6 2. weak; anterior setae on article 2 ofpereopod 5 It differs from G. longicomis in the short weak, article 6 moderatelyelongate; articles4-5 apical spines on the rami of uropods 1-2, the of pereopod 7 of broad form (in context of thick and short antenna 2, and the lack of the genus), article 5 weakly enveloping article 6, weakhumpingonurosomites2-3(soweakinG. dactyllarge;innerramiofuropods 1-2aslongas longicomis that we included it for comparison outer,peduncleofuropod 2with 2dorsalspines; despite item 1 above). apicalspinesonramiofuropods -2ofelongate 1 It differs from G. coalita in the short apical form (in context of genus); telson about 1.75 spines on the rami of uropods 1-2, thicker times as long as broad; epimeron 3 with poste- antenna2, muchbroaderarticle2 ofpereopod 6 roventral margin smoothly rounded; urosomite and the lack ofdouble hump on urosomites 2- 1 withweak rugose,setulosedoubledorsal crest, 3. urosomites2-3(fused)tall,with2almostevenly It differs from G. tenuipes in the thicker rounded dorsal humps, then sloping downward antenna 2, lack ofmarginal spines on the outer sharply posteriorwards, bearing about 1-7 ramus ofuropod 2, presence ofmarginal spines setules each; cuticle (light microscopy, lOOOx) ontheouterramusofuropod 1, and thebroadly with arcuate or semicircular scale-serrations in expanded articles 4-5 ofpereopod 7. lines, variable. It differs from G. timaru in the short apical spinesontheouterramiofuropods 1-2,broader Description. Eyesverylarge,lackingdeeppurple articles 4-5 of pereopod 7. basally broader ar- cores in alcohol; upper lip rounded-truncate ticle2ofpereopod 6, densersetaeon article 2of below (as in G. ipi/ya); right lacinia mobilis pereopod 5, more transversely arranged palms smallerand more weaklytoothed (4 small)than ofthe gnathopods, lack ofa spine on the inner left (6 large); outer plate of maxilla 1 with 7 ramusofuropod 3,much morearmamentedtel- spines; basis ofgnathopod 1 s-shaped, palms of son,broaderinnerplateofmaxilla2,and lackof gnathopods weakly serrate, medial faces ofpro- a thick spine-seta on the lateral margin ofmax- podi with only 2-4 weak setae, dactyls bearing illa 2. one large inner tooth; posterior margins on ar- ticle 6 of pereopods 3-4 not minutely ridged; Guernea (Guernea) yamminye sp. nov. pereopod 4 like 3 but article 5 with 1 less spine, article 4 with 1 less seta; epimeron 1 with Figures 4-6 (part) medium-small inward bending anteroventral Mma,tHeorrluiobatblylpeeex:awLmaiisznhaerdd.onI1slmaeanxdlt,ee.nnseiavreMerurbmbaliedpBleaainc,h,J1.-D2. 2luo-rbo5es;loaumrrigotepesoa1dcws,1itwohift2chosx3eatbaa6esovsfemanactlrilaaellrl,sye.atbGasieelnilnsttooafnncdcoeoxmxaa;e Thomas and J. Clark, 26 Jan 1989, NMV J20496 7. (male "a", 1.82 mm). Pleopods: ratio oflengths ofpeduncle, outer Additionalmaterial: Lizard Island, NorthPoint. 25 and inner rami for pleopods 1-3 = 27:29:30, m, sediment plain next to forereef, coral-algal mud 27:26:26, and 25:27:28; articles of outer and withHalimedaflakesoverlain byfineflocculent layer inner rami for pleopods 1-3 = 6-6, 6-6, 6-5; J.D. Thomas, 26Jan 1989, USNM 253723 (1 male)! coupling spines 2; each peduncle with 2 setae. Diagnosis. Accessory flagellum absent; antenna Summaryoftypicalmaledimorphicdistinctions. 2 unlobed but article 4 moderately thick; Smaller head with bulging eye lobes and mandibular incisors with 4 weak teeth, spine enlarged eye, elongate male-like antennae 1-2 row absent, molar without seta; inner lobes of withmalesetulartuftsonarticles4-5ofantenna lowerliplarge, fleshyand separate; palpofmax- 2; some mouthparts degenerating, for example, illa 1 degenerate, not reaching apex of outer rightlaciniamobilisweak,outerplateofmaxilla mplaaxtiel,luani2armtuiccuhlastheo,rltaecrkainngdsbertaoea;deirnntehrapnlaotueteorf p1owoirtlhyosneltyos7e,spimnaexsi,lplailppedobsroeldeuscceedn,t,smpaixnielslaon2 plate, bearing 1 apicomedial seta, outer plate outer plate shorter and blunter; anterior coxae with medium subtruncate apex bearing 8 setae; smaller relative to coxa 5; gnathopods slender; inner plate of maxilliped small, narrow, outer anterior setae on article 2 ofpereopod 5 weak, plate reaching middle of palp article 3, most posterior margin straight; pleonites 1-3 and medial spines blunt; gnathopod 2 narrower but pleopods more dominant; lobe on epimeron longerthangnathopod 1;coxa 5 with verylarge, weak; body rugose posterodorsaliy, urosomite I lobuliform, rounded posterior lobe, anterior with 2 ventral setae; uropod 1 with long1 NEW SPECIES OF GUERNEA (AMPHIPODA) FROM THE GREAT BARRIER REEF 307 Figure 5. Guerneayamminye, holotype, male "a", 1.82 mm. 308 J. D. THOMAS AND J. L. BARNARD Figure 6. Guerneayamminye, holotype, male "a", 1.82 mm.