Description of two new species of shore-eels (Gobiesocidae: Cheilobranchinae: Alabes) from south-eastern Australia and Norfolk Island

2006·2.6 MB·English

by  Barry Hutchins

5
MemoirsofMuseumVictoria63(1):25-28(2006)
iSSN 1447-2546(Print) 1447-2554(On-iine)
http://www.museum.vic.gov.au/memoirs/index.asp
Description oftwo new species ofshore-eels (Gobiesocidae: Cheilobranchinae:
Alabes) from south-eastern Australia and Norfolk Island
Barry Hutchins
DepartmentofAquaticZoology,WesternAustralianMuseum,LockedBag49,WelshpoolDC,WA6986
Abstract Hutchins,B. 2006.Descriptionoftwonewspeciesofshore-eels(Gobiesocidae: Cheilobranchinae:Alabes)fromsouth-
easternAustraliaandNorfolkIsland.MemoirsofMuseumVictoria63(1):25-28.
TwonewspeciesofAlabesarereported,onefromTasmaniaandtheotherfromNorfolkIsland.Thefirstissimilarin
generalappearancetoA.parvula,butisconsiderablysmallerinsize(to39mmSL)andinhabitswatersofmuchgreaterdepth
(160-348m).TheNorfolkIslandspecieshasauniquelyenlargedbuccalregionandispossiblyendemictothisisland.
Keywords Alabes,Cheilobranchinae,TasmaniaandNorfolkIsland,Australia
Introduction MethodologyfollowsthatofHutchinsandMorrison,2004.
The following abbreviations refer to cephalic pores of the
FollowingastudyoftheAustraliansubfamilyCheilobranchidae,
Hutchins and Morrison, 2004 described five new species of lateral line system: ANP, anterior nasal pore; LP, lacrymal
pore;PNP,posteriornasalpore;POP,postocularpore.Standard
Alabes, namely A. elongatus, A. gibbosus, A. obtusirostris, A.
occidentalisandA. scotti.Theyalsorecognisedfourpreviously length is abbreviated SL and head length is abbreviated HL.
described species, Alabes dorsalis Richardson, A. parvula Type material is held in the Australian Museum, Sydney
(AMS), Marine Research Laboratories, CSIRO, Hobart
McCulloch,A.hoeseiSpringerandFraser,andA.brevisSpringer
and Fraser, concurring with the findings of an earlier review (CSIRO),andMuseumVictoria,Melbourne(NMV).
(Springer and Fraser, 1976). The latter review also reported a
singleNorfolkIsland specimenofdoubtfulidentitybutcloseto KeytothespeciesofAlabes
A. parvula, and indicated that further specimens should be 1. Pelvic fin rudiment present, located on ventral surface
collectedbeforeits status couldbeverified.Asnonewmaterial immediatelybehindgillopening 2
of the Norfolk Island form had been forthcoming in the - Pelvicfinrudimentabsent 6
interveningyears,HutchinsandMorrison,2004preferrednotto 2. Pelvic fin rudiment moderate in size, fin rays present;
provideadescription,butdidincludeit,asAlabessp.,inatable POP 1 3
tothegenusindicatingitsuniqueidentity.Furthermore,theyalso - Pelvic fin rudiment small, pelvic fin rays (ifpresent) not
teoxaAmlianbeeds,bduotrsdaildinsotwhreipcohrthoan,dtbweoesnpeccoilmleecntsedofoafffsohromresimfirloamr visible;POP2,usuallywidely separated 5
Tasmaniaatadepthof160m(A.dorsalisisacommonintertidal 3. Pelvicfinrudimentwidthequaltoorwiderthanlengthof
species which occurs rarely to a maximum depth of 30 m). gill slit 4
However,thetwonondescriptspecimensweresmall(29-39mm - Pelvic fin rudiment less than length of gill slit
SLversusamaximumsizeof120mmforA.dorsalis),andwere (Tasmania) A. bathyssp. nov.
suspected of being juveniles that had possibly been carried 4. Body relatively robust (depth 9.3-11.6 in SL); dorsal fin
offshore by ocean currents. Recently a third specimen of this foldrelativelyhigh,continuedanteriorlytoverticalthrough
form was taken at an even greater depth (348 m) near King urogenitalopening(snouttooriginofdorsalfinfold2.0-3.
Island, just to the north-west of Tasmania. It proved to be inSL);blackishcircularblotchesoftenpresentonmiddleof
conspecific with the other two Tasmanian specimens, and sideofadult(NSW,Vic.,Tas.,andSA) A.dorsalis
although very similar to A. dorsalis, all three nevertheless - Body more slender (depth 12.5-14.9 in SL); dorsal-fin
represent an undescribed species. The purposes of the present fold relatively low, origin falling well short of vertical
paper, therefore, are to provide descriptions of these two rare through urogenital opening (snoutto origin ofdorsal fin
speciesfromNorfolkIslandandTasmania,andtoexpandthekey fold 1.3-2.4 in SL); no dark circular blotches on side of
ofHutchinsandMorrison,2004toincludethem. largeadult(WA) A. elongata
26 BarryHutchins
5. Head relatively large, length 61-1.6 in SL; PNP absent
(WA) A. brevis
- Headrelatively small,length9.7-11.4inSL;PNPpresent
(WA) A.gibbosa
6. Gill slit small, length 5.4-22.9 in HL; POP 1 or2; nasal
porespresentorabsent 7
- Gill slitmoderately large, length3.1-4.3 in HL; no POP
ornasalpores (Tas. andWA) A. obtusirostris
7. Origin ofdorsal-finfold oververtical through urogenital
opening or behind; anal-fin fold prominent, extending
about half way from caudal fin to urogenital opening;
interorbital relatively wide, width 5.4-10.8 in HL; body
translucent posteriorly in life, sides without alternating
blackandwhitebars 8
- Origin of dorsal-fin fold just behind head; anal-fin fold Ligure la.Alabes bathys, holotype, NMVA 14558,39 mm SL, off
absent or restricted to regionjust anterior to caudal fin; CapeSorell,Tas.(photographcourtesyofRudieKuiter,NMV).
interorbital very narrow, width 8.8-22.6 (usually 15 or
more) in HL; body orange in life (not translucent
posteriorly),sideswithalternatingwideblackandnarrow
whitebars(NSW,Vic.,andTas.) A. scotti
8. Postocularpores 1; PNPabsent; caudal-finrays lessthan
7orabsent 9
- Postocular pores 2; PNPusually present; caudal-fin rays
7-8(NSW,Vic.,Tas., SA,WA) A. hoesei l!Mllllllllll'IM'fiil f 'Ml'lMllllimil
9. Origin ofdorsal-finfold oververtical throughurogenital Ligurelb.Alabesbathys,paratype,CSIROH.6156-01,38mmSL,west
opening 10 ofKingL,Tas.(photographcourtesyofAlastairGraham,CSIRO)
- Originofdorsal-finfoldwellposteriortoverticalthrough
urogenitalopening(NorfolkI.) springerisp. nov.
10 Lacrymal pores present; male with pattern of regular Table1.Measurements(mm)andcountsoftheholotypeandparatypes
tiger-like bars anteriorly on side of body, not merging ofAlabesbathyssp.nov.
ventrally with longitudinal series of 4 blackish to dark-
blue blotches on side of abdomen, area of blotches Holotype Paratype Paratype
extending abouthalfwaybetweengill slitandurogenital NMV NMV CSIRO
- Lopaecnriynmgal(NpSorWe,sQalbds)ent; male withirregulararAr.apnagrevmuelnat A14558 A28045-001 H.6156-01
Standardlength 39 29 38
of tiger-like bars anteriorly on side of body, merging
ventrally with 2-3 blackish blotches which extend about Headlength 5.2 3.9 4.4
one-thirddistancebetweengillslitandurogenitalopening Snoutlength 1.3 0.8 1.4
(WA) A. occidentalis Eyediameter 1.6 1.2 1.5
Interorbitalwidth 0.7 0.5 0.6
Alabesbathyssp.nov. Gillslitwidth 1.4 1.1 1.4
Headwidth 2.4 2.1 2.4
Figures la,b;Table 1
MNaNteWriaolfeCxaapmeinSeodre.llHo(l4o2t°y1p0e.9.'NS,M1V44°A4184.59'5E8),,3W9HmOmISeLp,ibTeanst.,hi3c0sklemd BBooddyywwiiddtthha(tmagxil.l)slit 11..88 11..77 11..88
at 160 m, RS Wilson on board RV Soela (field no. S05/84 54), Bodydepth(max.) 3.0 2.3 2.9
20Oct1984. Snouttodorsal-finfold 14 9.2 15
Paratypes. NMVA28045-001,29mmSL,takenwithholotype Snouttoanal-finfold 19 11 22
(01d,isa3r8timcumlateSdL,clTeaasr.e,daKnidngstaI.inCeadnsykoelnest,alwmeastterioafl)K;iCnSgIIR.O(Hb.e6t1w5e6e-n VSennoturtaltofiannuwsidth 01.49 01.18 11.40
39°48'S, 143°08'E and39°50'S, 143°07'E), Sherman sled at348 m,
LRVSouthernSurveyor(fieldno.SS0404/35), 18Apr2004. Caudalfinrays 8 7? 8
Postocularpores 1 1 1
Diagnosis. Alabes bathys differs from all other species of Posteriornasalpores 0 0 0
Alabes by a combination ofits moderately large gill opening
(width 3.1-3.7 in HL), somewhat smaller pelvic fin rudiment Anteriornasalpores 1 1 1
(width 1.4-1.6ingillopening)consistingof2apparentfinrays Dorsallacrymalpores 1 1 1
in each half, 4 cephalic pores (1 POP, 1 ANP, 2 LP) in the Ventrallacrymalpores 1 1? 1
laterallinesystem,anditsuniquecolourpattern. Sex 9 9 9
Twonewspeciesofshore-eels 27
Description. Measurements oftheholotypeandparatypes are ventralfinrudiment,butdiffersintherelativelynarrowwidthof
presentedinTable 1 (counts andproportionsinparenthesesin the latter fin (maximum width 1.4—1.6 versus 0.8-1.0 for A.
the following description represent those of the paratypes dorsalis, all in length of gill slit). It also has a narrower body
where different from the holotype). Body elongate, (maximum depth 12.6-13.1 verus 9.3-11.6 in SL), lacks the
subcylindrical, widest anteriorly (maximum body width at dark circular markings along the body and its small size
level of gill slit 21.7 [17.1-21.1] in SL), reaching a maximum (maximumlength42mmTLversus 120mmTLinA.dorsalis).
depth about middle of body (depth 13.0 [12.6-13.1] in SL),
tapering posteriorly; head small, cylindrical, length 7.5 (7.4- Etymology. This species is named bathys (from the Greek
8.6)inSL,slightlywiderthanbody,width2.1 (1.8-1.9)inHL; “bathys”meaningdeep)withreferencetoitsdeepwaterhabitat.
snoutshort,roundtoslightlytruncateindorsalview,length4.0
(3.1-4.6) inHL;nostrils smallbutobvious, anterior 1 tubular, Alabesspringerisp.nov.
posterior 1 with low raised rim; eye moderate in size, with Figure2 Table2
prominentclearcornea, diameteroforbit3.3 (2.9-3.3) inHL, ;
bonyinterorbitalrathernarrow,width7.4(7.3-7.8)inHL. Alabesparvulus{nonMcCulloch)SpringerandFraser, 1976;21.
Skin smooth and scaleless, usually covered with mucus Materialexamined.Holotype.AMS1.18497-001,31mmSL,Norfolk
layer;lateralline sensory systemconsistsofsmall openpores L, Emily Bay,PointHunter(29°04'S, 167°57'E),rotenone at 1 m, C.
andminutepapillae(latterverydifficulttodetect);4poreson Andersonetal., 16Sep 1975.
each side ofhead, consisting of 1 POPand 1 ANP, and 2 LP. Diagnosis. Alabes springeri differs from all other species of
Gillopeningamoderatelywideslit,locatedonventralsurface Alabesby acombinationofits small gill opening (8.8inHL),
ofhead,length3.7(3.1-3.5)inHL;gills3?;branchiostegals3; lackofapelvic-finrudiment,narrowinterorbital space(8.8in
mouth terminal, gape not reaching vertical line through HL),presenceofonly2cephalicporesinthelaterallinesystem,
anteriormarginofeye(pigmentedarea),lipsnarrow,somewhat andtheposteriorlyplacedoriginofthedorsal-finfold.
fleshy; teeth in cleared and stained paratype small, conical,
caninedike, 1rowof6-8teethoneachsideofupperandlower Description. Measurements of the holotype, the only known
jaws, largestanteriorly (premaxilla also with3 much smaller specimen, are presented in Table 2. Body elongate and
teethforminga2ndrowalonginnerbaseofmainrow);palatine subcylindrical, reaching a maximum depth at level of about
andvomerineteethabsent. Dorsalandanal-finfoldsresemble anterior3rdofbody,thentaperingposteriorly,bodydepth 11.1
lowfins,butlackbothfinraysandunderlyingpterygiophores; in SL,maximumbodywidth(=widthatlevel ofgill slit) 15.5
caudal fin with 8 (7-8) fin rays, continuous with dorsal and in SL; caudal peduncleabsent(caudal finjoinedto dorsal and
anal-finfolds;basesofdorsalandanal-finfoldsrelativelylong, ventral-fin folds); head small, length 7.0 in SL, a little wider
insertion of dorsal-fin fold over or slightly behind vertical than deep (head width 1.9 inHL); snout short, ratherrounded
through urogenital opening, insertion of anal-fin fold well to slightlytruncateanteriorlyindorsalview,length3.1 inHL;
behindverticalthroughurogenital opening(snouttoinsertion nostrils small but obvious, anterioronetubular, posteriorone
of dorsal-fin fold 2.7 [2.6-3.2], snout to insertion of anal fin withlowraisedrim;eyemoderateinsize,withprominentclear
fold2.0[1.7-2.6],snouttourogenitalopening2.8[2.7-2.8],all cornea, diameter of orbit 3.7 in HL, noticeably greater than
in SL); urogenital opening with prominent papilla. Total bonyinterorbitalwidth(8.8inHL).
vertebrae not known for holotype but cleared and stained Skin smooth and scaleless, normally coveredwith athick
paratype has a total of 68 vertebrae, not including hypural mucus layer; lateral line sensory system consists of minute
plate(21 precaudal),withlastepineural on24thvertebra. papillae (latter very difficult to detect); cephalic pores 2 on
mCoolroeutrrainnslaulcceonhto.l. Head and body overall pale brown, fins eslaitc,hlosicdaeteodfohneavde,nt1raPlOsPurfaancde1ofAhNePa.d,Gwiilldtohpe8.n8inignHaLn;argrilolws
andbranchiostegals notexamined; mouth subterminal, upper
Colourinlife. (Based oncolourtransparency ofholotype, see jaw projecting over lower jaw, upper and lower lips rather
fig. la): head and body pale brown, abdominal region more narrow, rearcornerofmouthnotreaching anteriormarginof
pinkishventrally;bodybecomingmoretranslucentposteriorly, eye (pigmented area); teeth incisorform, 1 row in upper and
vertical fins almost totally transparent; middle of side with lowerjaws; palatine and vomerine teeth absent. Dorsal and
longitudinal seriesofwhitishspotsfromheadalmosttocaudal anal-finfolds resemble low fins, butlackingboth finrays and
fin, each spotabout equal or subequal to eye diameter; dorsal underlyingpterygiophores,continuouswithcaudal fin;caudal
surface with longitudinal series of similarly coloured short finwithoutvisiblefinrays,althoughthereis evidencethatthe
cross-bands, continued onto dorsal-fin fold as vertical bars; a posteriorportion ofthe specimenwas damaged at sometime
few pale spots on anal-fin fold. Largerparatype differs in its (portion ofcaudal and anal-finfolds lost, and some vertebral
groundcolour,beingamorepalegreyishgreen(fig. lb). elementsalsoprotrudingthroughsideofbody);basesofdorsal
and anal-fin folds relatively short, insertion ofdorsal-finfold
Distribution.Alabes bathysis known onlyfromwesternTas.,
well behind vertical through urogenital opening (snout to
intheregionofCapeSorrellandKingL.
insertion 1.8, snout to urogenital opening 2.6, both in SL),
Remarks.This specieshas sofaronlybeencollectedbydredge snouttoinsertionofanal-finfold 1.4inSL;urogenitalopening
from deep coastal waters at depths between 160 and 348 m. It with small papilla. Total vertebrae 71 (from Springer and
shareswithAlabesdorsalisalargeventralgillslitandprominent Fraser, 1976),withlastepipleural on20thvertebra.
28 BarryHutchins
Figure2.Alabesspringeri,hototype,AMS1.18497-001,31mmSL,NorfolkL,EmilyBay,PointHunter(illustrationcourtesyofVictorSpringer,
USNM).
Table 2. Measurements (mm) and counts ofthe holotype ofAlabes Remarks. This species inhabits shallow coastal waters (single
springerisp.nov. specimen taken from a depth of 1 m). It is most similar to
Alabes parvula from eastern Australia, differing in the
Holotype exceptionally shortbase ofthe dorsal-finfold, different shape
AMS ofthedarkbarsonthesideoftheabdomen(triangular-shaped
1.18497-001 versusmoresquarishinA.parvula),andtheexpandedshapeof
Standardlength 31 the buccal region (not expanded in A. parvula). Like other
Headlength 4.4 members of the Alabes parvula complex (A. parvula, A.
Snoutlength 1.4 occidentalis, andA. hoesei),itlacksapelvicfinrudiment,has
Eyediameter 1.2 averysmall gill slit,itsbodyprobablyistransparentinlife(at
leastposteriortourogenitalopening),anditsmaximumsizeis
Interorbitalwidth 0.5 less than 50 mm TL (see Table 1 in Hutchins and Morrison,
Gillslitwidth 0.5 2004). This species is named springeri in honour of V.G.
Headwidth 2.3 Springer (USNM) who, with T. Fraser in 1976, first reported
Bodywidthatgillslit 2.0 the apparentuniqueness oftheNorfolkIslandspecimen. (NB.
Bodywidth(max.) 2.0 registration number AMS 1.18470-002 was inadvertently
Bodydepth(max.) 2.8 assignedtothisspecimenbySpringerandFraser, 1973: 21,but
Snouttodorsalfinfold 17 thatnumberbelongs to one ofthe paratypes ofAlabes hoesei
Snouttoanalfinfold 22 whichwasdescribedinthesamepaper).
Snouttoanus 12
Acknowledgements
Caudalfinrays 0
Postocularpores 1 I am grateful to Alastair Graham (CSIRO), Martin Gomon
Posteriornasalpores 0 (NMV)andMarkMcGrouther(AMS)whoprovidedthematerial
Anteriornasalpores 1 on loan that was used in this study. Victor Springer (USNM)
Dorsallacrymalpores 0 kindly gave advice on the description ofthe new Alabes from
Ventrallacrymalpores 0 NorfolkIsland,andofferedmetheuseofapreviouslypublished
Sex Male? illustrationofthisspecies(fromSpringerandFraser, 1976).
Colour in alcohol. Head and body overall pale brown, fins References
more translucent. Springer and Fraser, 1976 illustrated some
partial cross banding on the abdominal region, triangular in Hutchins,J.B. andS.M.Morrison. 2004.Fivenewfishspeciesofthe
genusAlabes (Gobiesocidae: Cheilobranchidae). Records ofthe
shape(seefig. 2),butthishas sincefaded. AustralianMuseum56(2): 147-158.
Colourinlife. Unknown Springer, V.G. andT.H. Fraser. 1976. Synonymy ofthe fishfamilies
Cheilobranchidae (=Alabetidae) and Gobiesocidae, with
Distribution. Alabes springeri is known only from the type descriptions of two new species of Alabes. Smithsonian
locality(NorfolkI.). ContributionstoZoologynumber234: 1-23.