Sicafodiidae, fam. nov. for Sicafodia stylos, gen. nov., sp. nov., from the marine bathyal of south-eastern Australia (Crustacea: Amphipoda: Gammaridea)

2004·5.9 MB·English

by  Jean Just

MemoirsofMuseumVictoria61(1): 65-73(2004)
ISSN 1447-2546(Print) 1447-2554(On-line)
http://www.museum.vic.gov.au/memoirs/index.asp
Sicafodiidae, fam. nov. for Sicafodia stylos gen. nov., sp. nov., from the marine
,
bathyal ofsouth-eastern Australia (Crustacea: Amphipoda: Gammaridea)
JeanJust
MuseumofTropicalQueensland,78-102FlindersStreet,TownsvilleQueensland4810,Australia
([email protected])
HonoraryAssociate,MuseumVictoria,POBox666E,Melbourne,Victoria3000,Australia
Abstract Just,J.2004.Sicafodiidae,fam.nov.forSicafodiastylos,gen.nov.,sp.nov.,fromthemarinebathyalofsouth-eastern
Australia(Cmstacea:Amphipoda:Gammaridea).MemoirsofMuseumVictoria61(1):65-73.
Anewgenusandspecies,Sicafodiastylos,isdescribedfrombathyaldepths(400-1277m)offsouth-easternAustralia.
Followingadiscussionofitspossibleplacementinexistingfamilies,anewfamily,Sicafodiidae,apotentialsistertaxon
tothePardaliscidae,isestablished.Thenewspeciesischaracterisedbytheextremeelongationofitsconicallybundled
mouthpartsincludingtheinnerplateofthemaxillipeds,acompletelysmoothbody,short,broadlyroundedcoxalplates,
slender,simplebutstronglydissimilargnathopodsandelongatepereopods.Ananalysisofthefunctionalmorphologyof
themouthparts,includingmusclesintheupperlipandepistome,indicatesthatSicafodiastylosfeedsbypiercingitsprey
andsuckingupmacerated/liquefiedfood.Theactualfooditemsarenotknown.
Keywords Cmstacea,Amphipoda,Sicafodiidae,fam.nov.,Sicafodia,deep-sea,Australia
Introduction Barnard (1991) the species keys out in the vicinity of
The new species describedbelow was collected aspartofthe Lafystiidae and Laphystiopsidae on account of its simple
South-EasternAustralian SlopesProgramofMuseumVictoria mgannadtihbouploadr1r,akreorunsdeetade,.nNoonn-eeloonfgtahteesecocxhaareac1t-e3r,s iasndunilaqcukeotof
and the Victorian Institute ofMarine Sciences. The program thosefamilies.Bousfield(1983),BarnardandKaraman(1991)
mcaotmemleyn2c0e0dtion 12998060wmietthressa)mpolfifngsoautthbeatrhnyaNledwepStohust(hapWparloexsi,- aatndl,eabsytiLmapflyisctaitiidoane,,CaonldemfoarntahnedlBasatrntawrodw(o1r99k1s)paossssuibmleydatlhsaot
Bass Strait and eastern Tasmania, followed by a similar sam- A
Ppleirnagcaprridoagrwaamsibnro1u9g8h8t.tAo lhiigghth.lyAdpirveelrismeinaanrdynaonvaelylsifsauonfathoef Lr2ea0cp0eh0ny)ts,tphihooypwlseoivgdeeanree,,tipaclraeacnebasalsytishcioassleolfytarwmeoplahftiaempdioltdioefstahmieinliisepeshpia(mrBeaedtriegoeicdlesatd.eals.,,
composition and diversity ofIsopoda and comments on other neither with iphimedioid families. The Lafystiidae do, how-
groups of Crustacea, together with environmental data from
ever,showsomesimilaritieswiththeiphimedioids(seediscus-
thisstretchofcontinentalmargintowardstheTasmanSea,was
sionbelow)intheelongate,acuminatecoxa4andshort,robust
providedbyPooreetal. (1994). pereopods with curved dactyli, the conically pointed, but
rsopseTtcrhiuemmelnaeslnogantrgehdtoehfeposdspoiertcseiadmleicnnustrhvweaatcsuorlemleetcaotsituohrnesetdoifpfMrofoumsthetehuetmetlVispiocnot.ofrTtihhae,e wcheealkaltyegmnoadtihfoipeoddm2o.uFtohrpatrhtess,erseiamspolnes,gtnhaetfhaompioldyi1siamnpldicsiutbl-y
included in the general discussion ofthe iphimedioids below.
Melbourne,Australia.
Laphystiopsidaehave simple, identical gnathopods similarto,
but smaller than, pereopods 3 and 4, and quadrately bundled
Classificationofthenewspecies unmodified mouthparts. Laphystiopsidae bear little resem-
blancetothenewspeciesandwillnotbediscussedfurther.For
UsingBarnardandKaraman’s (1991)keytofamilies,thenew Ochlesidaeseediscussionbelow.
species falls among Ochlesidae (as Ochlesinae in their broad The mostimmediately obvious characteristics ofSicafodia
conceptoftheIphimediidae) andLafystiidaeonaccountofits stylos is the extreme elongation and acuteness of the down-
lackofamandibularmolarandthereducednumberofarticles ward,backwardpointingmouthpartbundle.Conicallybundled,
(three)inthemaxillipedalpalp.UsingthekeyinColemanand pointed mouthparts are uncommon in gammaridean
JeanJust
Amphipoda. They are found primarily in the conicostomatid elongateinS.stylos).Theexceptionstoquadratemouthpartsin
groupofgeneraintheLysianassoidea(seeLowryandStoddart, pardaliscids are Halicella Schellenberg (monotypic) and
1983),inmonotypicDidymocheliidae,intheiphimedioids,and RhynohalicellaKaraman(monotypic),inbothofwhichmouth-
intwogeneraofthePardaliscidae. partsforma small downwardorforwardpointedconerespec-
Sicafodia stylos clearly does not belong in the tively,butthestructureandreductionsofindividualmouthparts
Lysianssoidea, species of which have a characteristic body differsignificantlyfromthoseofS. stylos.
shapeandanelongateischiumandmittenshapedpropodusof Conicalbundling with some elongations andreductions in
gnathopod 2. Whilst there are some similarity in the mouth- mouthparts clearly has been independently derived in several
parts, notablyintheenlarged, foldedouterplate andtheelon- non-related families, and therefore does not in itself place
gate inner plate of the maxillipeds in some conicostomatid S. styloswithin any ofthe groups discussed. Disregarding the
genera, these similarities musthave be independently derived mouthparts, S. stylos appears tobe closerto the Pardaliscidae
to serve a similarfunction(see section onmouthpartfunction than to any of the other families mentioned. The prominent
below). inner plate of the maxillipeds and the dissimilar gnathopods
The three known species of Didymochelia (see Bellan- would appearto preclude the inclusion ofthe new species in
Santini and Ledoyer, 1986, Lowry and Stoddart, 1995) have that family, although it could be conceived as representing a
moderatelyconicalmouthpartbundles,butlittleornomodifi- separate subfamily taxon in the Pardaliscidae with extremely
cation ofmouthparts withregard to elongation orreductions. apomorphic mouthparts, but having retained a plesiomorphic
Furthermore,didymocheliidshavegnathopods 1 and2chelate, innerplateofthemaxillipeds,reducedorlostinallothermem-
pereopods 3-7 short and strong withcurved dactyli, uropod 3 bers ofthe family (the sisterclade). However, because ofthe
reduced to a stubby ramus only, and the telson shorter than lackofmales,andlackofcompleteantennae1and2andpereo-
wide, entire. Sicafodia stylos cannot be referred to the pods5and7inallspecimens,whichmightprovidefirmerclues
Didymocheliidae. to the placement ofthis species, I hesitate to place Sicafodia
Coleman and Barnard (1991) divided the non-eusiroid stylosin the Pardaliscidae. Instead, Ireferit to anew family,
iphimedioids into six families: Iphimediidae, Ochlesidae, Sicafodiidae, apotentialsistertaxonofPardaliscidae.
Acanthonotozomatidae,Acanthonotozomellidae,Dikwidaeand
Odiidae. Berge et al.(1999) merged Ochlesidae and Odiidae
Sicafodiidaefam.nov.
underthe formername. Species inthese families have conic-
allybundled,moreorlesselongatemouthpartswithavarietyof Diagnosis. Body broad, smooth; cuticle smooth. Cephalon
strongorless strongreductions. The strongestelongationsand shortwithwelldevelopedrostrum.Pereonite 1 enlarged,partly
reductions arefoundin species ofOchlesidae s.s. None, how- overlapping cephalon. Pleonal sideplates broadly rounded.
ever, exhibits the extremes found in Sicafodia stylos. Primary flagellum ofantennae multiarticulate (not confirmed
Iphimedioids have moderately compressed bodies (broadly forantenna2),accessoryflagellumpresent, 1-articulate,antenna
rounded dorsally in S. stylos), dorsal spines and/or carina 1 with callynophore commencing on first flagellar article.
(smooth), one or more of coxae 1-4 elongate, tapering and Coxal plates 1—4 apically rounded, barely longer than broad,
acuminate, or elongate and oddly shaped (Ochlesidae s.s.) overlapping, forming an even ventral curve, coxa 4 barely
(approximately as long as broad, non-tapering, apex broad, excavate posteriorly. Mouthparts elongate, grouped into
rounded),oneormoreofpleonalsideplates1-3withacutepos- sharplypointeddownward-backwardpointingcone. Upperlip
teroventral cornerand often with additional cusp onposterior apicallynotched.Mandibleswithoutmolarandspinerow,with
margin of sideplate 3 (broadly rounded, no cusps), pereo- 3-articulate palp, both mandibles with rod-shaped lacinia
pods 3-7 short, strong, ‘clinging’ with strong, curveddactylus mobilis. Lowerlip withmandibularlobes, innerlobes absent.
(slender, elongate, dactylus slender, nearly straight). Some Maxilla 1 withoutpalp,innerplatedigitiform, outerplatewith
iphimedioid families have simple, similar or dissimilar 9 distal spine-like setae. Maxilla 2 plates slender, with apical
gnathopods 1 and2;insomefamiliesbothgnathopodsaresub- and subapical setae only. Maxilliped with 3-articulate palp,
chelate or chelate; in others a combination; while they are outerandinnerplatesofsubequallength. Gnathopods 1 and2
carpo- or merochelate in Ochlesidae s.s. Simple gnathopods simple, strongly dissimilar. Pereopods 3-7 slender, dactyls
occurinmanygammarideanfamilies.Thus,therearenochar- slender,nearlystraight,pereopods5-7witharticle2expanded.
acters that unequivocally places S. stylos within the iphi- Urosomites free. Uropods with full complement of slender,
medioids, while its smooth dorsum, elongate, slender pereo- lanceolaterami,peduncleofuropod3 short.Telsonshort,lam-
pods 3-7 and short, rounded coxae 1-4inparticularpreclude inate, apicallyincised. Coxalgills simple sacks, onpereopods
suchanallocation. 2-7. Oostegitesonpereopods2-5, 2-4broad, sparsely setose,
Sicafodia stylos shares with Pardaliscidae a smooth body, 5linear.
shortsimplecoxae 1-4,simplegnathopods 1-2,slenderpereo-
Typegenus Sicafodiagen.nov.
pods 3-7 (5 and 7 assumed), and lanceolate uropodal rami. .
However, the gnathopods in S. stylos are highly dissimilar,
whereasinthePardaliscidaetheyaregenerallyofsimilarshape Sicafodia gen.nov.
and size. Pardaliscids normally have quadrately bundled
Typeandonlyspecies. Sicafodiastylossp. nov.
mouthparts,withbroadmolarincisorsandstronglyreduced(or
absent) inner plate of the maxillipeds (prominent and much Diagnosis.Withthecharactersofthefamily.
Anewbathyalamphipodfamily 67
Etymology.ThenameofthegenusisderivedfromLatin,sica, insertion ofaccessory flagellum; accessoryflagellum approx-
dagger, andfodio, to stab, hence ‘the one that stabs with a imatelyhalflengthofflagellararticle 1,distallytapering,with
dagger’, alluding to the shape of the mouthpart bundle. 1 apical and 1 subapical setae; article 1 offlagellum approx-
Feminine. imately two-fifths as wide as long, with single-field callyno-
phorecomposedof4-5 irregularrowsofaesthetascs, article2
and3 with2distalrowsofsimilaraesthetascs.Antenna2with
Sicafodiastylossp.nov. broad, apically pointed antennal cone; peduncular article 4
Figures 1-4 approximately twice as long as wide, reaching to apex offla-
Mmamt.erAiuasltraelxiaam,ienaesdt.erHnoTlaostmyapnei.a,FeomfaflFereywciitnhetdPeevneilnospuilnag,4ov1a°ri5e7s.,50'3S.,7 gseplelcairmaerntsi,clbeu1totfheanstheanpneao1f.t(hAenptreonxniamealotphaerrtwsiksneobwrnokseunggiensatlsl
148°37.90'E,400m,coarsebiogenicrubble,mud,WHOIepibenthic thattheflagellumofboth antennaeis simple, multiarticulate).
sled, M.F. Gomonet al., RVFranklin, 27Jul 1986 (stnSLOPE-48), Upper lip approximately 2.5 times longer than wide at base
NMVJ23915 (condition: antennae, somepereopods andtipofsome (anteriorview),narrowinginmiddle,taperingtowardsbilobed
uropodsbroken). apex,apicalnotchforminganarrowangle.Mandiblesstyliform
Paratypes(5specimens,allfromAustralia).Samedataasholotype, distal to insertion ofpalp, reaching to apex ofupper lip; left
NMV J23916 (femaleA, with apparent traces ofbroken oostegites; mandiblewithirregularlynotchedapex,laciniamobilisalong
condition: antennae andmostpereopods anduropods broken, telson slenderrodterminatinginstronglyobliquecuttingedgewith6
mm1i,9s8sW6inH(gOs)t.InESaeLspOtiPeberEnn-t3sh2lio)cp,eslNoefdM,BVaGs.sJC.2SB3t.9ra1iP7to,o(3rf8ee°mea2tl1e.a9l.B0,,'SR,wVi1t4hF9rf°aunl2kl0ly.i0nd0,e’vE2e,3l1oJ0pu0el0dy loarc7inisamamlolbdielnitsicqlueas;rtreirghttomhaanldfiblleengwtihthof3lbelftunltactieneitahampoibciallilsy,,
oostegites,4.6mm;condition:antennae,somepereopodsanduropods with bifid apex; strong palp inserted in proximal third of
broken), NMV J23918 (female C, with fully developed oostegites; mandibularbody, reaching slightly beyond apex ofmandible,
condition:halfspecimen,everythingposteriortopereonite6missing, article 1 as long as broad, article 2 approximately 4 times
antennaeandmostpereopodsbroken),NMVJ23919(femaleD,with longer than broad with 2-3 distal setae, article 3 approxim-
fullydevelopedoostegites;condition:halfspecimen,everythingposte- atelythree-quarterslengthof2,withupto4setaeonposterior
rior to pereonite 7 missing, antennae and most pereopods broken). marginandapproximately4apicalsetae,lateralsurfacepartly
EasternBassStrait slope, 67kmS ofPointHicks, 38°23.78'S, 149° coveredwithfinesetules.Lowerlipwithstyliformlobes,lobes
e1t7.a0l2.',E,RV111F9r-an1k2l7i7n,m,2f5inOecmtud1,9W88HO(sItnepSiLbOenPtEh-i6c7s)l,ed,NGM.CV.B.J2P3o9o2r0e fmiannedliybusletaorseloabpeiscaslhloyrtn,otsleqnudietre,rpeoaicnhtiinngg daipreexctloyfbmaacnkdwiabrldess.;
(1 specimen,condition: antennae, allpereopodsandmostofuropods Maxilla1outerplateapproximately 11timeslongerthangreat-
broken).
est width; distal 9 spine-like setae falling into three groups:
Description. Cephalon depth approximately 2.5 times mid- 2 apical setae (one coarsely serrate along entire length, one
lateral length. In lateral view cephalontapering towards right finely serratein distalquarter), 5 setaeclosely seton strongly
angled ventral comer. Ocularlobesbroadlyrounded, continu- oblique margin (regularly denticulate in distal half), 2 poorly
ing in nearly straight line to ventral comer. Eyes absent. articulating,flattenedmoreproximalsetaecloselyadpressedto
Rostrumaboutaslongasdeepinlateralview,apexroundedtri- medial surface ofplate, coarsely andirregularly serrate along
angular, approximately half length of non-rostral part of entiremargin; innerplate approximately thirdlength ofouter,
cephalon, ventrally forming a narrow angle with elongate, slender, cylindrical, tapering towards rounded apex, without
convexfronspartofcephalon.Epistomeshort,unproduced. setae.Maxilla 2outerplateapproximately9timeslongerthan
Pereonite 1 aslongasits anteriordepth, aslongas2and3 greatest width, with tuft of approximately 6 unequally long
combined. Pleosome dorsal length equalling combined length apical setae; inner plate approximately 80% length of outer,
ofpereonites2-7,pleonitesofequallength. with4 apical simple setaeand3 short, subapicalmedialbi-or
Coxal plates 1-4 with smoothly rounded ventral margin; trifidsetae.Maxillipedpalparticle1ovoid,approximately50%
plates 1-3 of subequal length when flattened, (appear to longerthan wide, article 2 approximately 80% lengthof 1, of
increaseinlengthfrom 1 to 3 inFig.l habitus, dueto 1 and2 similarshape,article3aslongas 1and2combined,thirdwidth
curving slightly inwards), of rounded rectangular shape but of2,approximately9timeslongerthanwidewith3or4groups
increasinginwidthfrom 1 to3;coxa1 length:width1.25,coxa of2or3setaeonmidlateralsurfaceandtuftsofapicalandsub-
2 length:width 1.20, coxa 3 length:width 1.0, coxa 4 apical setae; outer plates broad in proximal third, tapering
length:width 0.70, with rounded angular posterior projection towards truncate apex, apex withrow ofatleast 8 blunt, rod-
and weakconcavity posteriorto projection; coxa5 withlobes like setaeevenly decreasing inlength frommedial to penulti-
equally deep, anterior lobe wider, evenly rounded, posterior matelateralseta,lateralmostsetastouterthantherest,approxi-
lobe rounded rectangular; coxa 6 similar to 5, but posterior mately as long as medialmost one, curved mediad, with
lobe approximately thirddeeperthan anteriorlobe; coxa 7 an denticlesindistalquarter,(becauseofthenaturalforwardfold-
evenly rounded semicircle. Pleonal sideplates with smooth ingofouterplates aroundremainingmouthparts,Fig.2Cmxp
margin;plate 1 withweaklyangularapex,2and3rounded. dv, thelateralmost, denticulate seta, Fig. 2Amxp op, is func-
Antenna1,pedunculararticle1aslongas2and3combined, tionallyinamedialposition, cf. above); innerplatesnearly as
approximately 10%longerthanlateralwidth,articles2and3of longasouterplates,eachplateslenderwithnearlyparallelmar-
subequal length, both somewhat telescoped into preceding gins,terminatinginbluntlypointedapexwithwhatappearsto
article, article 3 with lateral apical margin extended beyond be glandular tissue in terminal part (Fig. 2C mxp ip), plates
68 JeanJust
Figure1.Sicafodiastylos,gen.nov,sp.nov.Holotype,exceptB,paratype,femaleB(NMVJ23917).al,antenna1;a2,antenna2;af,accessory
flagellum;c,head;lv,lateralview;or,outerramusup3;t,telson;up3p,uropod3peduncle;us,urosome.Habitusscalebar: 1mm.
Anewbathyalamphipodfamily 69
Figure2.Sicafodiastylos,gen.nov.,sp.nov.A,paratype,femaleA(NMVJ23916);C,paratype,femaleC(NMVJ23918);D,paratype,female
D(NMVJ23919);H,holotype. av,anteriorview;dv,dorsalview;ep,epistome;ip,innerplate;1,left;11,lowerlip;1,rmd,mandible;mxl,2,
maxilla1,2;mxp,maxilliped;op,outerplate;r,right;ul,upperlip;vv,ventralview;asterisk:tipofmandibleandlaciniamobilisbroken.
70 JeanJust
Figure3. Sicafodiastylos, gen. nov., sp. nov. Holotype, exceptB, paratype, femaleB (NMVJ23917). ex, coxa; gp, gnathopod; o, oostegite;
p,pereopod;pi,pleopod.
Anewbathyalamphipodfamily 71
with small opposing notch in medial margin proximal to Gnathopod2 little more thanhalfthe length of 1, without
‘gland’, each plate laterally, between notch and ‘gland’, with elongate elements; carpus approximately 80% the combined
tuft of4 or 5 inward curving setae decreasing in length from length of ischium and merus, triangular, approximately 50%
lateraltomedial. longer than lateral distal width, posterodistal lobe setiferous,
Gnathopod1basisapproximately4timeslongerthanbroad, not projecting along propodus; propodus approximately 10%
as long as merus and carpus combined, with anterior longi- longerthancarpus,moderatelycurved,taperingdistally,with4
tudinal concavity to receive article 5 when fully folded back; or 5 posterior groups ofstiff, pectinate setae, anterior margin
ischiumapproximatelytwiceaslongaslateralwidth;merustri- with group of similar setae at distal two-thirds; dactylus half
angular, anteriorlypointed, approximately as long as ischium, length ofpropodus, similarto that ofgnathopod 1 but with 2
withcarpus inserted on anteriormargin; carpus slender, twice smallmidposteriorteeth.
aslongasmerus,withparallelmargins,approximately6times Pereopods 3 and 4 similar, slender, approximately 4 times
longer than wide, unarmed; propodus approximately 65% longerthanrespectivecoxalplates;merusandcarpussubequal
longerthancarpus, 12timeslongerthanbroadatbase,slightly inlength,combinedaslongasbasis;propodustwiceaslongas
curvedandfaintly tapering distally, withafew shortposterior carpus; merus, carpus and propodus with a few posterior and
setae; dactylus weakly curved, approximately sixth length of anterior small setae, propodus with small posterodistal robust
propodus, with posterior tooth near base of stout, curved seta; dactylus halflength ofpropodus, nearly straight, length
unguis, 1 straight, simple seta level with tooth and 2 curved, approximately eight times width at base. Pereopods 5-7
blunt,simplesetaeatposteriorbaseofandadpressedtounguis. apparentlyalike(pereopod6theonlyentirelimbknown,hence
72 JeanJust
relative lengths of5-7 not known, but probably of subequal maxillipeds are brought fully forward, a tight funnel may be
length), with posteriorly expanded distally rounded basis, createdbetweentheforward-inwardfoldedouterplatesandthe
posteriormarginsmoothwithscatteredsetules,withmidlateral elongate upper lip (as in Acidostoma)', the equally elongate
and anterolateral ridges; at least pereopod 6 approximately innerplatesofthemaxillipedswillhelpsealthefunnelposter-
third longerthan pereopods 3 and 4, but otherwise ofsimilar iorly. Oncetheapexofthemouthpartconeisembeddedinthe
shape and proportions, carpus posterodistally and propodus fooditemtissueandatightfunnelhasbeenestablished,asuck-
posteriorlywithgroupsofslenderrobustsetae. ingdevisemaybefoundintheproximalpartofthe upperlip,
Pleopods strong, alike; peduncle approximately twice as whereobliquelysettransversemuscles(Fig.2Aul,lv)will,on
long as wide (posterior view), with 2 mediodistal coup- contraction,pullthe soft-walledposteriorsurface oftheupper
ling hooks; subequalrami as long as peduncle, proximal part lip forward thus drawing liquid or semi-liquid food upward
of rami with opposing surfaces excavate, outer ramus with through the funnel. The obliquely transverse muscles in the
posteriorproximallockingprojection. epistomemayhave asimilarfunction, bringing foodcloserto
Urosomite 1 as long as 2 and 3 combined; urosomite 2 the oesophagus. Additional mechanisms, like those described
dorsal length approximately quarter that of elongate 3; uro- byDahl(1964),havenotbeenobservedbutmaybepresentto
somite 3 dorsally flattened to slightly concave in transverse finallyliftfoodintothestomach.
section. Uropods 1 and 2, peduncles withlateralrobust setae; Following the initial piercing by the mandibles, the apical
uropod 1 overreaching2andouterramusof3,(tipofuropod1 andsubapicalspine-likesetaelocatedonthemaxillipedalouter
ramibrokeninallspecimens,butproportionsbetweenramiand plateandtheouterplateofmaxilla 1mayhelpinextendingthe
peduncleprobablyapproximatingthoseinuropod2);uropod2 woundand shreddingthetissue. Ifthetipsofthemaxillipedal
shorterthan 1,reachingnearlytotipofouterramusof3,outer inner plates are indeed glanduliferous as suggested in the
ramus as long as peduncle, inner ramus approximately 40% description, such glandsmayreleaseproteolytic enzymesinto
longer than outer; uropod 3 biramous (innerramus lost in all the wound and thus help speeding up the maceration process
specimens,butpresenceindicatedbysocketandmusculature), beforesuctiontransport.
peduncleaslongaswide,reachingtotipoftelson,outerramus The actual food items ofSicafodia stylos are not known.
approximately 5 times longer than peduncle; rami of all However, the lack ofgrasping gnathopods or strongly dacty-
uropodsslenderlanceolate,withoutterminalseta(e),butappar- late, clinging pereopods suggest that Sicafodia is not a fish
ently all withafew smalllateromarginal setae, margins finely parasite. In view of its slender epibenthic/pelagic pereopods
serrate. Telsonapproximately 10%broaderthanlong,reaching 3-7 and the strongly developed pleosome the species is
todistalmarginofpeduncleofuropod3,quartercleftinopen probably a roaming predator on some group or groups of
V-shape;lobesrounded,eachwith2distolateralmarginalteeth, sessileorsluggishbenthicorepibenthicinvertebrates.
2 or3 smallpappose setaelevel withteethand 1 long similar
setaatmid-surface. Acknowledgments
Size. Largestfemale,4.7mm.Malenotknown.
Thematerialreportedwasobtainedduringtwocruisesonboard
Etymology. The species name is derivedfromtheLatinstylus theAustralianNational Facility shipthe RVFranklin in 1986
meaning pointed instrument or pen, and os meaning mouth, and 1988. The South-Eastern Australian Slopes Program of
alludingtothelong,pointedmandibles.Nouninapposition. Museum Victoria, Melbourne, and the Victorian Institute of
Distribution. South-easternAustralia,400-1277mdepth. Marine Sciences (nolongerinexistence), Melbourne, andmy
participation in thatprogram were supported by a grant from
the Australian Department of Science’s Marine Sciences and
Functionofthemouthparts
TechnologyScheme/AustralianResearchCouncil. IthankJim
Conicallybundled,elongate,pointedmouthpartsarefrequently Lowry, Australian Museum, Sydney, for valuable discussions
referredto ashavingpiercing andpossibly suckingfunctions. andcommentsduringthepreparationofthispaper.Ialsomust
In most cases the piercing action can be readily understood, acknowledge the greatpleasureofdiscussingthis new amphi-
whereasthe subsequenttransportoffood(particles,macerated podwithJerryBarnardonhislastvisittoAustralia,andlisten-
tissue,bodyfluids)hasnotbeenstudiedindetail. Dahl(1964) ingtohisextraordinary ‘spiel’oftalkingmethroughtheentire
discussedtheprobablefunctionofthemouthpartsandadjacent key to gammaridean families from memory. In the end he
parts ofthedigestivetractinAcidostomaneglectaDahl, 1964 lookedatthenewspeciesinwonder.
(Lysianassoidea; ectoparasite on sea anemones, Vader, 1983).
Hefoundthatmusclesinthe oesophagus andtheanteriorpart References
ofthe stomach may createthe necessary negative pressure to
lift up food through the narrow passageways ofthe conically Barnmaarrdi,neJ.gL.a,mmaanrdiKdaeraanmaAnm,phG.ipSo.d1a99(1e.xcTehpetfmaamriilnieesagnadmmgaernoeirdas)o.f
bundledmouthparts.
RecordsoftheAustralianMuseum,Supplement13(1): 1-417.
In spiteofmany differences in mouthpart details, the gen- Bellan-Santini, D., and Ledoyer M. 1986. Gammariens (Crustacea,
eraloutlineofthebundleisquite similarbetweenAcidostoma Amphipoda)desilesMarionetPrinceEdward.BolletinodelMuseo
and Sicafodia. Sicafodia also seems to possess the two pre- CivicodiStoriaNaturaleVerona 13:349^435.
requisites necessary for sucking up food through the mouth Berge,J.,Boxshall,G.,andVader,W. 2000.Phylogeneticanalysisof
cone,viz., atightlumen, andasuckingmechanism.Whenthe the Amphipoda, with special emphasis on the origin of the
Anewbathyalamphipodfamily 73
Stegocephalidae. Polskie Archiwum Hydrobiologii 47(3-4): Lowry,J.K.andStoddart,H.E.,1983.Theshallow-watergammaridean
379-400. Amphipoda of the subantarctic islands of New Zealand and
Berge,J.,Vader,W.,andColeman,O. 1999.Acladisticanalysisofthe Australia: Lysianassoidea. Journal ofthe Royal Society ofNew
amphipodfamilies Ochlesidae and Odiidae, withdescriptionofa Zealand13(4):279-394.
new species and genus. Crustaceans andtheBiodiversity Crisis: Lowry,J.K.,andStoddart,H.E. 1995.AnewspeciesofDidymochelia
239-265,KoninklijkeBrillNV:Leiden. from New Caledonia (Crustacea: Amphipoda: Didymocheliidae).
Bousfield, E.L. 1983.Anupdatedphyletic classification andpalaeo- Bulletin du Museum national d’Histoire naturelle, Paris (4) 17
history of the Amphipoda. In: Schram, F.R. (ed.), Crustacean (1-2): 193-200.
Phylogeny.CrustaceanIssues1:257-277. Poore,G.C.B.,Just,J.,andCohen,B.F. 1994.Compositionanddiver-
Coleman,C.O.,andBarnard,J.L.1991.RevisionofIphimediidaeand sityofCrustaceaIsopodaofthesoutheasternAustraliancontinental
similar families (Amphipoda: Gammaridea). Proceedings ofthe slope.Deep-SeaResearch41(4):677-693.
BiologicalSocietyofWashington 104(2):253-268. Vader, W. 1983. Associations between amphipods (Crustacea:
Dahl, E. 1964. The amphipod genus Acidostoma. Zoologische Amphipoda)andseaanemones(Anthozoa,Actiniaria).Memoirsof
Mededelingen39:48-58. theAustralianMuseum18: 141-153.