Notoraja hirticauda, a new species of skate (Chondrichthyes: Rajoidei) from the south-eastern Indian Ocean

2006·6.7 MB·English

by  Jeffrey M Leis

MemoirsofMuseumVictoria63(1):65-75(2006)
iSSN 1447-2546(Print) 1447-2554(On-iine)
http://www.museum.vic.gov.au/memoirs/index.asp
Notoraja hirticauda, a new species ofskate (Chondrichthyes: Rajoidei) from the
south-eastern Indian Ocean
PeterR. LasPandJohnD. McEachran^
'CSIRO,MarineLaboratories,G.P.O.Box 1538,Hobart,Tasmania7001,Australia([e-mail])
^Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, U.S.A
([e-mail])
Abstract LastP.R. andMcEachranJ.D. 2006.Notorajahirticauda, anewspecies ofskate(Chondrichthyes: Rajoidei) fromthe
south-easternIndianOcean.MemoirsofMuseumVictoria63(1):65-75.
Anewskate,Notorajahirticaudasp.nov.,isdescribedfromoffcentralWesternAustraliainthesouth-easternIndian
Ocean.Itisdistinguishedfromitscongenersinsomeproportionalmeasurements,thedistributionsofdermaldenticlesand
bristle-likethorns,theabsenceoforonasalpits,andseveralskeletalstructures.Thenewspecieshasarelativelylongsnout,
multipleirregularrowsofshortthornsonthedorsalandlateralsurfacesofthetail,anddermaldenticlesontheventral
surfaceofthetail.Itsrostralcartilage,whichislongerthanthenasobasallength,hasappendicesthataresubtriangularin
cross-sectionposteriorlyandabuttherostralshaft.WithinNotoraja,N.hirticaudamostcloselyresemblesN.subtilispinosa
StehmannfromthePhilippinesandIndonesia.
Keywords Chondrichthyes,Rajidae,newspecies,skate,Notorajahirticauda,south-easternIndianOcean
Introduction 30 species occurringoffAustralasia(LastandYearsley, 2002).
However, relationships within the clade, which includes the
The highly diverse and endemic rich skatefaunas ofAustralia
andNewZealandarerepresentedbyatleast62species,ofwhich fpualvloyraujnidneersstuobogdr.ouMpcsEaancdhrInasnenatnidraLjaasYtea(r1s9l9e4y)ahnadvLeasstu,gagreestneodt
all but two appear to be restricted to the Australasian region that Brochiraja (as Subgenus A) is a subgroup of Notoraja
(LastandYearsley, 2002). Similarly, ofthe40 orsoAustralian rather than Pavoraja, as originally suggested by McEachran
species(LastandStevens, 1994),onlyonealsooccursoffNew (1984). However, elucidation of the relationships within this
Zealand. Several new species have beenidentifiedfromrecent genericcomplexisdependentondescriptionsofothermembers
exploratory,trawl-fishingcatchesinAustralianseasbutmostof withintheclade.NotorajawasresurrectedbyStehmann(1989)
theseremainundescribed. Forexample,therajoidfaunaoffthe andpresently containsfourvalidnominal species,N. laxipella
westerncoastofAustraliaconsistsofatleast14speciesofwhich (Yearsley & Last) and N. ochroderma McEachran and Last
onlythreehavebeendescribed(LastandStevens, 1994).Many fromnorth-easternAustralia,N.tobitukai(Hiyama)fromJapan,
of these appear to have narrow depth and geographic ranges. and N. subtilispinosa Stehmann from the Philippines and
Among the least well-known skates, at both specific and Indonesia, although other species are known to occur in the
supraspecificlevelswithinthesuborder,areAustralianmembers Indo-westPacific (McEachranandLast, 1994).Anew species
oftheNotoraja-Xike,skates. of Notoraja is described below based on material from the
McEachran and Miyake (1990) presented a cladogram continental slopeoffWesternAustralia.
dividing rajoids into two major clades: Group I consisting of Severaldifferentmethodsfortakingexternalmeasurements
nine supraspecific taxa including the pavorajine subgroups of skates have been proposed. This has caused considerable
PavorajaWhitley,NotorajaIshiyamaandarecentlydescribed confusion in the past, so our methods are explained here in
genus,Brochiraja (LastandMcEachran, 2006;formerly as an some detail. We usedthepoint-to-pointapproachproposedby
unnamedtaxon“SubgenusA”ofPavoraja,sensuMcEachran, Hubbs andIshiyama(1968),butrawdataarefinallyexpressed
1984);andGroupIIconsistingof11supraspecifictaxaincluding asproportionsoftotallengthratherthandiscwidth.Thepreoral
“typical”rajine subgroups suchasRajaandDipturus. GroupI lengthis defined as the measurementfromthe snouttiptothe
skates are well representedinthe westernPacific with atleast anteriormedianedgeoftheupperjawratherthantothemouth
66 PeterR.LastandJohnD. McEachran
proper. Mouthwidthisthe greatestdimensionacrossthetooth pits; rostral cartilage about 1.25 in nasobasal length; rostral
bandoftheupperjawratherthanvisiblewidthoftheupperjaw appendices about 62% of nasobasal length, subtriangular in
between the inner margins ofintegument (Yearsley and Last, cross-section posteriorly and evenly abutting rostral shaft;
1992). Spiracular measurements referto distances around the pectoral radials 61-66; trunk vertebrae 24-27, precaudal tail
main depression and do not include the anterior secondary vertebrae71-76;andbothsurfacesofbodypale.
depression. The maximum and minimum widths ofthe nasal
Description. Disc heart-shaped, 1.11 times as broad as long in
curtain refer to the greatest dimensions across the curtain holotype (1.11-1.16 times in paratypes); maximum angle in
(usuallyacrossthelobes) andthewidthbetweentheinnermost
frontofspiracles73-75° inadultmales,93-97° infemalesand
insertions of the curtain immediately before the mouth
juveniles;anteriormargininitiallystraight,slightlymoreconvex
respectively.Thenasal lobedimensionisthe greatestwidthof in females and immatures, moderately concave opposite
the lobefromthe insertion ofthe curtainto its lateral margin. spiraclesinmaturemaleholotype;posteriormarginandcomers
Pelvic-finlobelengths aretakenfromthe pointofarticulation
broadlyconvex(figs 1,2).Snouttoaxisofgreatestwidth61.5%
ofthe anteriorlobe as describedbyMcEachranand Stehmann
(57.7-60.9%) of disc length. Snout tip with prominent fleshy
(1984)andStehmann(1985)ratherthanfromthehaemal spine
andlaterallyflattenedapicalprocess;processratherbroad-based
(HubbsandIshiyama, 1968).Thewidthofthepelvic-finbaseis and almost continuous with anterior profile of disc in mature
the minimum distance between these points of articulation.
males, more lobe-like in immatures and adult females. Pelvic
Measurements to the cloaca originate from near its posterior fins deeply incised, anterior lobe moderately long, narrow at
margin (i.e. approximated from the origin ofthe first haemal baseandtaperingtobluntpoint;posteriorloberelatively short,
spine) ratherthan at its midpoint. Skeletal measurements and withstronglyconvexlateralmargins;anteriorlobelength95.7%
countsfollowHubbsandIshiyama(1968) andMcEachranand
(93-113%) of posterior lobe. Tail narrow at base, tapering
Compagno(1979, 1982).
Some mature paratypes were dissected to reveal the gradually posteriorly, very slender toward tip; moderately
depressed over length, width 1.42 (1.44—1.72) times height at
structure of the neurocranium, scapulocoracoid and clasper;
skeletal elements werehighlightedwithAlcianblue eightGS axilofpelvicfin;slightlyconvexonventralsurface;lateralskin
foldsoriginatingwellbehindposteriorpelvic-finlobes,extending
cartilage stain. All specimens were radiographed to verify
tobelowmid-lengthofepichordalcaudal-finlobeandbroadening
anatomicaldissections,tocountvertebrae,teethandpectoral-
distally(onlyslightlynarrowerthanheightofepichordallobe);
fin radials, and to determine the shape of the pelvic girdle. lengthoftailfromrearofcloaca1.40(1.40-1.50)timesdistance
ASupsetcriamleinansNeatxiaomnianleEdisihnCotlhilsectsitound,yCwoemrmeonowbteaailntedhSfcrioenmtitfhiec fromtip ofsnoutto rearofcloaca; predorsal tail length78.1%
(78.2-81.4%) of tail length; width at midlength of tail 2.06
andIndustrialResearchOrganisation,Hobart(CSIRO).
(1.99-2.72) inorbitdiameter; widthataxils ofpelvic fins 0.80
(0.85-1.00) in orbit diameter. Dorsal fins ofsimilar shape and
Notorajahirticaudasp.nov. size;rathershortandmoderatelytallwithevenlyconvexanterior
Eigures 1-8,Tables 1-3 margin;posteriormarginstraightorslightlyconvex;tippointed
Notorajasp.C—LastandStevens,1994:312,figs33,34.5,PI50 ocaruadcault-efliynrlooubnederde;laftinisvesleypawrealtleddbeyveslhoopretdi,ntesresppaarcaet.eEdpibcyhosrhdoarlt
(allfig.captionsincorrect,asN.spB).
interspace from and distinctly longerthan 2nd dorsal-fin base;
Materialexamined.Holotype.Australia: CSIROH1816-02,446mm hypochordalcaudallobeverylow,originatingnearendoflateral
TL, mature male, west of Shark Bay, Western Australia, 26°36'S, fold,notconfluentwithepichordallobe.Preorbital snoutlength
112°P0a9r'aEt,y7p6e0s(mn,=82)8:DAeusctermalbiear:C19S8I9,RORVCA“2A8k2e0b,on3o12Mmarmu”T,Ls,taf.e4m1a.le, 4.02(3.15-3.50infemalesandimmatures)timesorbitdiameter;
CSIRO CA2821, 264mmTL,female,northofNickol Bay,Western preoralsnoutlength2.29(1.98-2.35)timesintemarialdistance.
Australia, 18°38'S, 116°54'E,600m,7Apr1982,LRV“Soela”,Cr.2, Orbitdiameter1.17(1.11-1.45)timesinterorbitaldistance; 1.87
sta. 30; CSIRO CA2822, 241 mmTL,female, CSIRO CA2823, 277 (2.02-3.08)timeslengthofspiracles.Lateralnasalfoldexpanded
mm TL, female, north of Nickol Bay, Western Australia, 18°41'S, slightly, with weak triangular process along lateral margin,
116°45'E, 596 m, 6 Apr 1982, LRV “Soela”, Cr. 2, sta. 28; CSIRO posterior margin smooth or with a weak fringe; nasal curtain
CA2824,361 mmTL,immaturemale,northofNickol Bay,Western moderatelywelldeveloped,broadlyroundedandweaklyfringed
Australia, 18°43'S, 116°33'E,612m,7Apr1982,LRV“Soela”,Cr. 2, (often hardly detectable) along posteriormargin. Oronasal pits
sta. 29; CSIROH1816-03,448mmTL,maturemale, capturedwith absent. Upperand lowerjaws slightly arched on either side of
holotype;CSIROHI822-0I,372mmTL,female,westofSharkBay, symphysis; upperjaw of holotype indented at symphysis, not
W“eAskteebronnoAuMsatrraul”i,a,sta2.6°4404;'SC,SI11R2O°19H'2E5,747-3056,m,42828mDmecTL,198f9e,maRleV, uinpdpeenrtjeadwi,n3f4em(a3l2e-s3a9)ndseirmimeastiunrelso.weTreejtahw;inp3l6ate(-3l5ik^e0w)istehrisehsoritn
westofLreycinetEstuary,WesternAustralia,26°38'S, 112°30'E,500
m,30Jan1991,LRV“SouthernSurveyor”,Cr. 1,sta.37. qcuuisnpcsunicnialfleym.alDeiss,tacnucsepsbeatcwueteenly1sptoigniltledsliitns 1m.a7l2es(,1.a6r3r-a1n.g91e)d
Diagnosis. A small species of Notoraja with the following times distance between nostrils; distance between 5th gill slits
combination ofcharacteristics: preoral snout 13.5-15.2% TL; 1.07 (1.04—1.27) times distance betweennostrils; length of 1st
preorbital snout 12.3-13.8% TL; mutiple irregular rows of gillslit6.7(4.7-8.4)timesmouthwidth.
small,bristle-likethornsandlargedermaldenticlespresenton Dorsal surface of disc, posterior lobe ofpelvic fin, dorsal
bothsurfacesoftail;singlepreorbitalthornpresent;nooronasal fins,epichordallobeofcaudalfin,andlateralskinfoldsdensely
Newskatefromthesouth-eastern IndianOcean 67
Table1.MorphometricdatafortheholotypeofNotorajahirticaudasp.nov.,withrangesandmeansforparatypes.Measurementsareexpressed
aspercentagesoftotallength
Holotype Paratypes
CSIRO
H1816-02 n=8
Min Max Mean
Totallength(mm) 446 241 448
Discwidth 48.7 47.3 51.3 48.7
Disclength 43.7 41.8 45.2 43.0
Headlength(dorsal) 17.8 16.9 17.7 17.4
Headlength(ventral) 25.1 23.1 25.7 24.3
Snoutlength(preorbital) 13.8 12.3 13.2 13.0
Snoutlength(preoral) 15.2 13.5 15.0 14.6
Prenasallength 11.1 10.1 11.0 10.5
Snouttomaximumwidth 26.9 24.5 26.6 25.7
Orbitdiameter 3.3 3.8 4.2 3.9
Distancebetweenorbits 2.8 2.7 3.5 3.0
Orbitandspiraclelength 4.3 4.2 5.0 4.5
Spiraclelength 1.8 1.3 2.1 1.7
Distancebetweenspiracles 5.4 5.4 6.3 5.7
Mouthwidth 7.2 5.7 6.6 6.3
Naretomouth 4.3 3.6 4.7 4.2
Distancebetweennostrils 6.1 6.0 6.4 6.2
Widthoffirstgill slit 1.0 0.8 1.2 1.0
Widthofthirdgill slit 0.8 0.9 1.3 1.1
Widthoffifthgill slit 0.7 0.9 1.1 0.9
Distancebetweenfirstgill slits 10.6 10.4 11.7 11.1
Distancebetweenfifthgill slits 6.5 6.4 7.8 7.2
Lengthofanteriorpelvic-finlobe 13.7 13.1 15.0 14.4
Lengthofposteriorpelvic-finlobe 12.2 12.3 14.5 13.4
Tailwidthataxil ofpelvicfins 4.1 4.0 4.5 4.2
Tailheightataxil ofpelvicfins 2.9 2.5 3.1 2.7
Tailwidthattipsofpelvicfins 3.9 3.2 3.9 3.6
Tailheightattipsofpelvicfins 2.4 2.1 2.6 2.3
Widthoftailacrossitsmidpoint 1.6 1.5 2.0 1.7
Distance—snouttocloaca 41.7 40.1 42.4 41.0
Distance—cloacato 1stdorsal fin 45.3 45.6 48.4 46.8
Distance—cloacato2nddorsal fin 50.0 50.2 52.2 50.8
Distance—cloacatocaudal-finorigin 54.5 54.0 56.0 55.0
Distance—cloacatocaudal-fintip 58.3 58.4 61.0 59.5
Numberoftoothrows(upperjaw) 36 35 40 38.2
Numberoftoothrows(lowerjaw) 34 32 39 35.6
Numberoftrunkvertebrae 26 24 27 25.4
Numberofprecaudaltailvertebrae 72 71 76 73.0
Numberofpectoral-finradials 63 61 66 64.2
PeterR.LastandJohnD. McEachran
Table2.Morphometricdatafotrtheneurocraniumofparatype(CSIROH1822-01)ofNotorajahirticaudasp.nov.Measurementsareexpressed
aspercentagesofnasobasallength
Neurocranium %length
Nasobasallength(mm) 31.4
Craniallength 72.8 231.8
Rostral cartilagelength 39.3 125.2
Rostral cartilagewidth 1.6 5.2
Prefontanellelength 33.1 105.4
Cranialwidth 39.0 124.2
Interorbitalwidth 10.1 32.3
Rostralbase 3.8 12.0
Anteriorfontanellelength 14.4 45.9
Anteriorfontanellewidth 3.9 12.5
Rostral appendixlength 19.3 61.5
Rostral appendixwidth 5.4 17.2
Rostral cleftlength 10.8 34.4
Cranialheight 7.4 23.5
Widthacrossoticcapsules 19.0 60.5
Widthofbasalplate 9.0 28.7
Greatestwidthofnasal aperture 16.4 52.1
Leastwidthofnasalaperture 7.0 22.4
Internasalwidth 3.9 12.5
Table3.Morphometricdataforthescapulocoracoidofparatype(CSIROH2574-06)ofNotorajahirticaudasp.nov.Measurementsareexpressed
aspercentagesofscapulocoracoidlength
%
Scapulocoracoid length
Scapulocoracoidlength(mm) 22.7
Scapulocoracoidheight 17.2 75.5
Premesocondyle 9.0 39.6
Postmesocondyle 13.7 60.4
Postdorsalfenestralength 6.5 28.8
Postdorsalfenestraheight 5.2 23.0
Anteriorfenestralength 2.9 13.0
Anteriorfenestracombinedheight 6.5 28.8
Baselength 20.6 90.6
Anteriorcornerheight 16.4 71.9
Posteriorcornerheight 12.8 56.1
Newskatefromthesouth-eastern IndianOcean 69
Figure1.Notorajahirticaudasp.nov.Holotype(CSIROH1816-02,446mmTL,male),a.Dorsalview;b.Ventralview.
70 PeterR.LastandJohnD. McEachran
Figure 3. Squamation on the mid-tail of Notoraja hirticauda sp.
nov. Holotype (CSIRO H1816-02, 446 mm TL, male), a. Dorsal
view;b.Lateralview.
fig. 4b
fig. 4a fig. 4c
Figure4.NeurocraniumofNotorajahirticaudasp.nov.Paratype(CSIROH1822-01,maturefemale,372mmTL:a.dorsalview;b.lateralview;
c.posteriorview),fig.abbreviations:ac-anteriorcerebralveinforamen,af-anteriorfontanelle,antc-antorbitalcondyle,bf-basalfenestra,end-
endolymphaticforamen, es-efferentspiraculararteryforamen,hf-hyomandibularfacet,into-intercerebral veinforamen,ja-jugal arch, IbX-
lateralisbranchofvagusnerveforamen,obf-oticbranchoffacialnerveforamen,oc-occipitalcondyle,of-orbitalfissure,one-orbitonasalcanal
foramen, os-optic stalk, peri-perilymphatic nerve foramen, pf-posteriorfontanelle, poc-preorbital canal, postp-postorbital process, prep-
preorbitalprocess,prof-profundusnerveforamen,pterp-pteroticprocess,ra-rostralappendix,rb-rostralbase,rn-rostralnode,rs-rostralshaft,
Il-optic nerve foramen, Ill-oculomotor nerve foramen, Vll-hyomandibular branch of facial nerve foramen, IX-glossopharyngeal nerve
foramen,X-vagusnerveforamen.
Newskatefromthesouth-eastern IndianOcean 71
Figure5. LateralviewofleftscapulocoracoidofNotorajahirticaudasp.nov. Paratype(CSIROH2574-06,maturefemale,428mmTL). fig.
abbreviations:ab-anteriorbridge,ac-anteriorcorner,adf-anterodorsalfenestra,avf-anteroventralfenestra,msc-mesocondyle,mtc-metacondyle,
pdf-postdorsalfenestra,prc-procondyle,pvf-postventralforamina,rc-rearcorner,scp-scapularprocess.
Figure6.VentralviewofpelvicgirdleofNotorajahirticaudasp.nov. Figure7.Lateralview,partiallyexpanded,ofrightclasperofNotoraja
a. Holotype, (CSIRO H1816-02, male, 446 mm TL); b. Paratype hirticaudasp.nov.Holotype(CSIROH1816-02,446mmTL,male),
(CSIROH2574-06,female,428mmTL).fig.abbreviations:ilp-iliac fig. abbreviations: cf-cleft, hy-hypopyle, pj-projection, pr-
process,obf-obturatorforamina,prep-prepelvicprocess. pseudorhipidion,rh-rhipidion,sl-slit,sp-spike.
72 PeterR.LastandJohnD. McEachran
fig. 8a
Figure8. Rightclaspercartilages ofNotorajahirticaudasp. nov. Holotype(CSIROH1816-02,446mmTL,male): a) lateralview;b) dorsal
view; c) ventral view. fig. abbreviations: atr2-accessoryterminal 2 cartilage, ax-axial cartilage, dmg-dorsal marginal cartilage, dtrl-dorsal
terminal 1 cartilage,dtr2-dorsalterminal2cartilage,tb-terminalbridge,vmg-ventralmarginalcartilage,vtr-ventralterminalcartilage.
Newskatefromthesouth-eastern IndianOcean 73
coveredwithfine,moreorlessevenly spaceddermaldenticles; Pelvic girdle with short prepelvic processes (fig. 6); iliac
thorns(fig. 3) small,delicate,confinedtotail andpreorbit, and processes moderately well developed, strongly recurved;
alar regions of mature males. Denticle cusps on disc very ischiopubicregionrelativelynarrowerinmalesthaninfemales,
slender, erect and slightly recurved; bases quadriradial, radii with straight anterior margin in males and weakly convex
arrangedmore orless atright angles, anteriorradius generally margininfemales,butwithstronglyconcaveposteriormargins
shortest (sometimes barely detectable). Both surfaces of tail inbothsexes;iliacregionwith2-3 obturatorialforamina.
densely covered with denticles and small, bristle-like thorns; Clasperslong,veryslender,proximaltoandnotexpandedat
thorns variable in size, scattered, interspersed with denticles; origin of glans (fig. 7); without dermal denticles or pseudo-
medianthornsinanalmostlinearseries,otherthornsdistributed siphon; glans weakly depressed, moderately expandable. Inner
randomly or in irregular series; largest thorns long-based, dorsal lobe with pseudorhipidion extending from level of
somewhat compressed, sharply pointed distally, upright and hypopyle and medial to slit, to about distal quarter of glans;
triangularorwithnarrowrecurvedtips;mostnumerousdorsally continuingdistallyalmosttoglansmarginasafoldofintegument;
on centre of tail; thorns on ventral surface of tail generally lobewithdeep cleftlateraltopseudorhipidion; slitproximalto
smaller than those dorsally but much larger than denticles of cleft;spurandflagabsent.Ventrallobewithoutshield;pelawell
disc. Single, rather short preorbital thorn present. Alarthorns developed, extendingfromlevel ofhypopyleinto distal halfof
stronglyrecurvedanddirectedpostero-medially,central group glans; projection slightly curvedlaterally, extendingforalmost
inindistinctrows andmergingwithaclusterofsmallerthorns halflengthofglansfrombeneathpelatoitspointed,nakeddistal
nearanterioroutermarginofpectoral fin; holotypewithabout tip near glans margin; spike disc-shaped with sharp, naked
5-6 central rows, eachwith 1-4thorns (maturemaleparatype lateral and distal margins, ventral to projection, partly covered
with about 9-12 rows, each with 1-2 thorns); all thorns non- bysentinabutdisto-lateralmarginvisible.Axialcartilagewitha
depressible,obliquelyorientedtosurfaceofdisc,notfittinginto slenderconicaltip; extendingwellbeyondothercartilages(fig.
slits in integument. Claspers, anteriorlobes ofpelvic fins, and 8). Dorsal marginal cartilage not expanded distally; with a
ventral surfaces of disc and posterior pelvic-fin lobes naked; truncatedistalborder(withthedorsalterminal2cartilage)anda
integumentofventral surfaceratherdelicate. long,slender,distomedialextensionformingthepseudorhipidion.
Dorsalterminal 1 cartilagerelativelynarrowandband-likewith
Skeletal morphology. Neurocranium with nasobasal length irregular anterior and posterior margins; located at about
20.7%ofdistancefromsnouttoposteriormarginofcloacaand midlengthofpelaandenvelopingaxialcartilage.Dorsalterminal
80.5%ofcranialwidth.Rostralshaftslender,ofmoderatelength, 2 cartilageratherbroad, almostspatulate distally; connectedto
about 125% ofnasobasallength;rostralbase 12% ofnasobasal medial aspect of axial cartilage by well-developed terminal
length (fig. 4, Table 2); rostral appendices long, flattened bridgeandlooselyconnectedtotipofaxialbyconnectivetissue.
anteriorly, subtriangular in cross-section and abutting (rather Ventral marginal cartilage not flared laterally at level of
than fused to) rostral shaft posteriorly; propterygia ofpectoral hypopyle; extending almost to distal margin of accessory
girdlereachingrostralnode;nasalcapsulesverylarge,ovoid,set terminal2(ascomponentprojection).Ventralterminalcartilage
at about 26° to transverse axis of neurocranium; foramen for J-shaped; proximo-medial condyle articulating with ventral
profundus nerve near antero-lateral margin of nasal capsules; marginal cartilage, disto-medial extension articulating withtip
preorbital process poorly developed; postorbital process poorly ofaxialcartilage;innerlimbseatedneararticulationofaccessory
developed and barely distinct from pterotic process; anterior terminal 2 and ventral marginal cartilages; acute proximal tip
fontanellevery narrow, with acutely rounded apex andbilobed not forming component eperon; disto-lateral margin strongly
posterior margin, extending to leading edge of nasal capsule; curved inward and not forming component shield. Accessory
posterior fontanelle indistinct (not visible in radiographs and terminal 1cartilagelacking,possiblyfusedwithventralterminal
onlydetectableafterstaininganddissection),irregularlynotched cartilage to form component projection. Accessory terminal 2
duetobroadmarginofacellularperichondrialtissue,fontanelle cartilage with large disc-shaped distal extension forming
covered with dense fibrous connective tissue; basal fenestra component spike; articulating with postero-medial margin of
kidney-shaped; anteriorcerebral veinforamen antero-dorsal to ventralmarginalcartilage.
optic nerve foramen and above orbito-nasal canal foramina; Colourinpreservative. Dorsal surface straw-colouredto pale
oculomotor nerve foramen dorsal to optic stalk; jugal arches greyish-yellow, minute melanophores scattered widely over
weak; basal plate and intemasal plate relatively narrow, about mostofsurface; ventral surfacewhitishwithtranslucentskin,
28.7%and 12.5%ofnasobasallengthrespectively. palest near margins of disc, minute melanophores lightly
Scapulocoracoid of female moderately short, longerthan scattered over tail. In life, paler, creamish to white above,
deep, tapering slightly posteriorly; lateral face expanded pinkish over body cavity and head; eyes black; tail brilliant
slightly between mesocondyle and metacondyle (fig. 5, Table white; skintotallytransparentventrally,visceradistinct.
3d)o;rsaanltefreinoerstbrraidslgieghwtliydel,artgheirn,thsatnroanngtleyridoerpvreenstsreadl;faennteestrriao;r Size.A small skateattaining atleast448mmmmTLand222mm
discwidth;malesmaturinglargerthan360 TL.
scapularprocesselevatedaboveantero-dorsalmargin;anterior
corner weakly angular, antero-lateral margin very slightly Distribution. Knownfromthe south-easternIndian Ocean on
convex;rearcornernotextendeddistally;mesocondyleslightly the central western sector ofthe Australian continental slope
depressed; postdorsal fenestra moderately expanded, oval; 3 (betweenSharkandNickolBays,WesternAustralia),indepths
postventralforamina,central smallest. of 590-760 m. Apparent stenobathic and narrow geographic
1
74 PeterR.LastandJohnD. McEachran
rangesmaynotbeanartefact;trawldatafromdepthsshallower tobitukai andA. laxipella (ie. 24-27 and 61-67 for vertebral
anddeeper,andinareasadjacentthegeographicrange,included and radial counts respectively). Both counts are higherforA.
othersympatricrajoidspecies,butexcudedN. hirticauda. ochroderma(30-32 and87-89forvertebral andradial counts
A respectively).Similarly,thescapulocoracoidofA.hirticaudais
Etymology. combinationoftheLatinhirtus(roughorbristly) more similartothoseofA. subtilispinosa,A. tobitukaiandA.
daenndticclaeusdoan(btoaitlh)siunrfaalcleussioofnthteotatihl.eKdneonswenbcoyvtehreagveernoafcuflianre mlaoxriepelellaontghaatnetsocatphautloocfoAr.acoocidhrwoidtehramavewrhyilcahrghea,shoarriezloanttiavlellyy
‘ghostskate’.
expanded post-dorsal fenestra. Notoraja hirticauda has three
Remarks.Notorajahirticauda fits the diagnosis ofNotoraja as postventralforaminalikefemalespecimensofA.subtilispinosa
defined by Stehmann (1989) and McEachran and Last (1994), andA.laxipellaexaminedtodate(fourinA.tobitukaiandfive
except that the tail is unusually thorny (compared to thorns in A. ochroderma). The pelvic girdle ofA. hirticauda most
absentorinamedialrowinotherNotorajaspecies),therostral closely resembles that of A. tobitukai. In both species, the
cartilage(includingnode)isdistinctlylongerthanthenasobasal anterior contour ofthe ischiopubic baris slightly convex and
length (rather than about equal in length), and the rostral the prepelvic processes are short and rather robust. The
appendices are subtriangular posteriorly and abut the rostral prepelvic processes ofA. subtilispinosa and A. ochroderma
shaft (ratherthan plate-like and running closely parallel to the are much more slender and the anterior contour of the
shaft). Notoraja hirticauda is further distinguished from its ischiopubic barofthe latteris straight (McEachran and Last,
nominalcongenersA.laxipella,N.ochroderma,Nsubtilispinosa, 1994).Asdiscussedabove,theneurocraniumofA.hirticauda,
.
andA.tobitukai,inproportionalmeasurements,lackingoronasal like A. laxipella, has a relatively long rostral shaft and
pits,coloration,andinsomeskeletalstructures.Ofthesespecies, appendices compared to other species of Notoraja but the
Notoraja hirticauda exhibits greatest overall similarity to A. presence of jugal arches is shared by A. laxipella and all
subtilispinosa. Itis also superficially similartoA. laxipellabut membersofthegenusexceptA. ochroderma.
has tail thorns (otherwise absent), a well-developed anterior The fontanelle structure of the neurocranium of A.
bridge in the scapulocoracoid (rather than thin or absent), a hirticaudadiffersfromthenormalconditionfoundinskates.A
robustterminal bridge in the clasper (ratherthan incomplete), posteriorfontanelleiswelldevelopedinmostrajoids.Stehmann
andfewerprecaudal vertebrae. The relatively long snoutofA. (1989) could not detecteitheranteriororposteriorfontanelles
hirticauda(preorbital snoutlength 12.4—13.7%)ismoretypical in the neurocranium in radiographs of the holotype of A.
ofA.laxipella(13.4—14.7%TL)thantheoth&rNotorajaspecies subtilispinosa, and Ishihara and Stehmann (1990) observed
(10.8-12.5% TL). A longer snout is also evident from the onlyananteriorfontanelleinradiographsofasecondspecimen
prenasal length (10.1-11.0% vs. 8.9-10% TL in these other from Indonesia. Similarly, only the anterior fontanelle was
Notorajaspecies)andintheshapeoftheneurocranium(rostral detectableinX-rays oftheneurocraniaofA. hirticaudatypes,
cartilagelength 125%inA.hirticaudavs.88-92%ofnasobasal althoughanill-defined,posteriorapertureoverlainwithsmooth
length in A. tobitukai and A. subtilispinosa). Notoraja uncalcified cartilage and dense connective tissue was evident
ochrodermahas arelatively long rostral cartilage (ie. 104% of from dissection.Asimilar, poorly-defined posteriorfontanelle
nasobasallength;McEachranandLast, 1994)butitisstillmuch exitsinA.laxipella.Incomparison,theposteriorfontanellesof
shorterthanthatofA. hirticauda.NotorajaochrodermaandA. other related Australasian skates (ie Notoraja ochroderma,
hirticauda(combined orbitand spiraclelengths3.5^.7%TL), Irolita, Pavoraja and Brochiraja) are sharply defined in
andA.hirticauda(4.2-5%TL),havesmallerorbitsandspiracles radiographs(LastandMcEachran,unpubl.).
thanA. tobitukaiandA.subtilispinosa(5-5.7%TL). The rostral appendices are considered to be important
Members of the genus Notoraja also exhibit significant evolutionary characteristics (McEachran, 1984: McEachran
interspecificvariationinthemouthandtail sizes,thepelvic-fin and Miyake, 1990). Three Notoraja species (A. tobitukai, A.
shape,andthegill-slitsizeandinterspacing.Notorajahirticauda subtilispinosa and A. ochroderma) are considered to possess
appearstohavesmallergillslits(eg.firstgill-slitwidth0.8-1.2% plate-likerostralappendices(Stehmann, 1989;McEachranand
vs. 1.2-L5% TL) and narrower intergill distances (eg. width Last, 1994).Thesestructuresarethickened,almosttriangularin
between first gill slits 10.4—11.7% vs. 11.5-13% TL) than A. cross-section distally in A. hirticauda, and more closely
subtilispinosa. The anteriorpelvic-fin lobe varies greatly from resemble the subconical appendices found inA. laxipella and
slightly shorterin mature males (anterior93-96% ofposterior Brochiraja. Eurther inspection of the neurocranium of A.
lobe) to slightly longerthanthe posteriorlobe inmostfemales laxipellarevealedarelativelythinner,rostralcartilageseparated
(typically 104—110%) of A. hirticauda. The anterior lobe is slightlyfromits appendices (ratherthancontinuously abutting
subequalorlongerinA.subtilispinosaandA.tobitukai(anterior themasinA.hirticauda).
100-117%inposteriorlobe)andshorterthantheposteriorlobe TheexternalformoftheclasperofA.hirticaudaisconsistent
inA.ochroderma(anterior76-90%inposteriorlobe).Notoraja withthe generaltypefoundinBrochirajaandNotoraja,except
hirticaudaandA.tobitukai(tailwidthatpelvic-fintips3.2-3.9% forA.ochroderma,whichhasaneperonandashieldformedby
TL) have a slightly broadertail than A. subtilispinosa and A. the sharp proximal margin of the ventral terminal cartilage
laxipella (width at pelvic-fin tips 2.2-3.1% TL). The four (McEachran and Last, 1994). The dorsal terminal 1 cartilage,
NotorajaspeciesappeartohavelargermouthsthanA. laxipella smallinA.hirticauda,isabsentinA.ochrodermaandsometimes
{5.1-1. vs.4.8-5.5). absent in A. tobitukai. McEachran and Last (1994) suggested
The pectoral-fin radial and trunk vertebral counts of A. that the “rhipidion” of Notoraja, Pavoraja and Irolita is
hirticauda closely resemble those of A. subtilispinosa, A. structurally different and probably not homologous with the