'Melanochlamys handrecki' Sp. Nov.: An Addition to the Opisthobranch Fauna (Mollusca: Gastropoda) of South-Eastern Australia

2010·1.2 MB·English

by  Robert Burn

.
In memoryofClarrieHandreck
Melanochlamys handrecki sp. nov.: an addition to the opisthobranch
fauna (Mollusca: Gastropoda) ofsouth-eastern Australia
RobertBurn
MarineResearchGroup,FieldNaturalistsClubofVictoria,Blackburn,Victoria3130
Abstract
AnewinfaunalspeciesMelanochlamyshandrecki (AglajidaeJisdescribedfromcoastalembaymentsofcentralVictoria
andwesternTasmania.ThenewspeciesiscomparedwithitslocalcongenerMelanochlamysqueritorandtheNewZea-
landMelanochlamyslorrainae.{TheVictorianNaturalist127(6),2010,231-235)
Keywords: Aglajidae, newspecies,south-easternAustralia,lowerintertidal
SpeciesofthegenusMelanochlamysCheeseman, their own species, and nenierteans which are
1881,likeallmembersofthebubble-shellfamily ingestedjustasahumanwouldsuckinalength
Aglajidae,haveareducedinternalshell hidden ofspaghetti (Rudman, 1972b).
away in the posterior or posterior-dorsal part Gosliner (1980) includes eight species in
ofthe body. The shell is fragile, white, and in Melanochlamys. Since then three species have
shape closely resembles the top or posterior been synonymised with others (Burn, 1974;
quarterofthecommontemperateAustralasian Chaban and Martynov, in Kantor and Sysoev
bubble-shellBullaquoyti.Withfewexceptions, 2006) andthestatusofsomeremainsdoubtful.
species ofthe family lack radular teeth in the One species is common in south-eastern
pharynx;insteadofteeth onaribbonactingas Australian low intertidal and shallow subtidal
a‘pick-upandconveyorbelt’ forthepassageof waters. Melanochlamys queritor (Burn 1957)
food to the stomach, aglajids suckin live prey (Fig. 1), described in this journal a little over
and pressurepass’ittothestomachwhereitis 50years ago, rangesfromsouthern NewSouth
digested. Aglajid prey includes acoel, polyclad Walesto southernWesternAustralia including
andpolychaeteworms,shelledopisthobranchs, Tasmania (Burn 1989). A rare and presently
other species of the family Aglajidae, even
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Fig. 1.Melanochlamysqueritor-dorsalviewoflivespecimenfromEaglesNest,Inverloch.
Vol 127 (6) 2010 231
In memoryofClarrie Handreck
Lindescribed speciesofthe genus is listed from of the body, wider and shallowly arcuate in
theBassStraitarea(Burn2006).Athird,newly front, narrowly truncate behind, shallowly
found,speciCvSisdescribedherein. grooved along mid-line. Anterior edge of
All material has been deposited in Museum head shield thickened and grooved. Visceral
Victoria, Melbourne. humpnarrowerin frontwhereitemergesfrom
beneath the tightly adpressed posterior flap
Melanochlamyshandreckisp. nov. (Figs2-4) ofthe head shield, becoming wider as it frees
Material from the parapodia, and terminating in a pair
Shallow Inlet, Waratah Bay, South Gippsland, ooff vsihsocretralrouhnudmepd olovbeersh.anLgowienrdelnatteerdalgreodogvees
Vmiecmtobreira,sof3t8h"e5M1a'Sr,ine14R6e"s0e9’aEr,chGcroolulepc,teFdNCVb:y along body wall. Tliin margin of parapodia
18 March 2009, 1 speMciVmen, 15 mm long, alive vtweor-ythcliorsdeslyboaddpyrehesisgehdt.toInbosdecytisoind,espaartapaobdoiuat
(dissected Paratype F169259); 7 March
mm narrowly curved out from body, together with
2001m,m5 specimens,4,6, 6, 7,M1V4 long alive the indented groove forming a wide siphonal
(14 specimen Holotype F169257,four
smallerspecimens Paratypes MVF169258). canalalong eachside. Footbroad, alittlewider
in front, rounded behind. Eyes not visible
Habitat dorsally or laterally. On each side ofmouth is
Found at low tide in areas of clean sand a small cream quadrangular pad from which
surrounding small Zostera beds. Specimens short hyaline sensory bristles intermittently
burrow just below the sand surface and are project. Posterior to each pad, a large brown
not visible except for the track they leave cuticularisedpatch(Hancock’sorgan).
behind. The sand areas are densely populated Pharynx approximately one quarter ofbody
with polychaete worms, which form semi- length, ovoid, muscular. Penial sheath with
consolidatedsandtubesthatprojectoneortwo an internal muscular flap, with a shoi't free
millimetresabovethesurface. posterior penial papilla, and a single prostrate
gland. Shell with broad outer lip, the upper
Description
mm mm edge projectingas a sharp pointthatis housed
Liveanimal to 15 mlmong, almost6 at its within the right posterior lobe ofthe visceral
widest, and about 4 high. Body elongate
hump; inner whorls broadly conical and very
oval, a little wider towards the posterior, and
much depressed. Head shield half length fragile.
Fig2. Melanochlamyshandrecki-dorsalviewofliveParatype, MVF169259.
232 TheVictorian Naturalist
In memoryofClarrieHandreck
Fig3.Melanochlamyshandrecki-leftlateralviewofliveParatype.MVF169259.
Fig4.Melanochlamyshandrecki-internalviewofshellofdissectedParatype,approximately3.5
X2.5mm.
Dorsal surface of head shield and visceral Discussion
hump almost black. Orangeish viscera visible Melanochlamys handrecki is readily separated
withinleftsideofvisceralhump.Parapodialight fromitslocalcongenersbythebroaddepressed
grey dorsally, becoming much paler ventrally, body, the closely adpressed, narrowly curved
to dull white on the sole. Small specimens are parapodiathat do not reach high up the body
palerdorsally. sides, the broader outer part ofthe shell with
projecting point, the large brown Hancocks
Voll27 (6) 2010 233
In memoryofClarrieHandreck
organs, and the grooved anterior edge of the SupplementaryNotes
head shield. In Melanochlamys qneritor, the Subsequent to the completion of this paper,
body is cylindrical, the parapodia rise higher a larger and differently coloured specimen
and are held closer to the bodysides, the shell of Melanochlamys handrecki was submitted
is more posterior within the visceral hump to the writer for examination. Tlie following
and is smaller and more tightly coiled, the observationsweremadeofthespecimen,which
Hancocks organs are not colour differentiated, was maintained alive for 11 days in a large Hat
and the eyes are visible anterior-laterally in bowlwithsand from itshabitatatoneend.
the groove separating head shield from foot. Tile specimen was tbund by Trevor
Melanochlamys sp. (Burn, 2006), known only McMurrich at the end of a sand track in
from one or two specimens, has a cylindrical 60cmwaterdepthalCurlewis,OuterCorioBay,
body like that ofMelanochlamys queritor, but Port Phillip Bay (38n0'S, 144*^3pR) on 29 July
differs from that species and Melanochlamys 2010. Several additional animals were seen at
handrecki by the presence of a cuticularised thesametime,includingan apparently mating
styletarmingthepenialtip,andanopaquewhite pair. All weremuchthesamesize,thecollected
body sparsely spotted with brown. (Coleman, specimen measuring 30 mm in length and 11
mm
2001,p 119,lower righthandfigure). in breadth. All wereglossy black dorsally,
The six live specimens of Melanochlamys making themarginsofthe posteriorflap ofthe
handrecki were very uniform in colouration, head shield and ofthe parapodia very difficult
except that the smallest specimens were notas todistinguish.Theanteriorcornersofthehead
darkgreyonthedorsalsurfaces.Melanochlamys shield and the sole of the foot were a more
queritorvariesconsiderablyincolour.Typically smokyblackcolour,andtheinnersurfaceofthe
it is blackwith abluish sheen from theminute parapodia was pale blue-grey. The sole of the
cilia that cover the body, with lighter cream footofthecollected specimen wasdemarcated
anterior corners and posterior edge of the fromtheparapodiaalongeachsidebyanarrow
head shield,but grey,brownand almostcream shallowmusculargroove, otherwiseilmatched
animals, plain or mottled, have been observed exactly the description above, even to the
overtheyears. Brown mottled specimens were presence ofshort hyaline sensorybristles each
described as Melanochlamys henri Burn, 1969 sideofthemouth.
butwerelatersynonymisedwithMelanochlamys jMclanochlamys handrecki creates a mucous
queritor{^urn 1974). tube to protect its bodyas it burrows through
mm
Detailsofthepenialsheath,sizeofthepharynx thesandysubstrateapproximately3 below
and shape of the shell of Melanochlamys thesurface. Itis onlyrarelyvisiblefrom above.
lorrainae (Rudman 1968) from northern Themucoustubecollapsesimmediatelybehind
New Zealand are similar to these features in the moving animal, resulting in a distinctive
mm
Melanochlamys handrecki. Initially described shallow groove, 11-12 wide, narrowly
fromawhiteanimal(Rudman 1968),additional deeper in the mid-line and margined each
mm
specimens range from white to mottled grey side by a 2-3 high ridge. Rive days after
withpaleranteriorandposteriorends(Rudman collection, the specimen laid a small, soft
mm
1972a). Specimens ofMelanochlamys lorrainae sphericalhyalineegg-mass 13 indiameter,
figuredonthe‘SeaSlugForum' (Rudman 2010) anchored by a very short stout holdfast to a
are creamy white with sparse grey mottling mucous-bound mass ofsand grains buried in
confinedto themedian lineofthe head shield, thesedimentsurface.Numerousverysmallbut
and all over the sole and parapodia. One well spacedoval eggcapsules,440 x320 pm in
specimen shown has very dark grey terminal size,each containingasinglecreamywhiteegg,
lobes of the visceral hump. Melanochlamys measuring380x220pm,wereclusteredwithin
mm
lorrainae is separated from Melanochlamys anapproximately9 diameterspherewithin
handrecki by its more cylindrical body, and the egg-mass. This egg-mass is very similar to
muchpalercolouration.
234 TheVictorianNaturalist
In memoryofClarrieHandreck
that of Melanochlamys cylindrica from New BurnR(1969)AmemorialreportontheTomCrawfordcol-
Zealand, but in thatspecies the eggs appearto lcoelcotgiiocnalofSoVciicettoyrioafnAuOsptirsatlhioab1r(a1n2c)h,i6a4.-J1o0u6r.naloftheMala-
fill the wholeoftheegg-mass andthe holdfast Burn R (1974) Notes on some benthonic opisthobranchs
isMaelloanngocshllenadmeyrsthharnedardec(kRiuhdamsaanls1o9b7e2ae)n.found BufSrorncoimeRtPy(o1or9ft8AP9uh)sitlOrlpaiilpsiBaUaiy3o,(b1Vr)i,acn4toc7rh-i4sa9.(.SJuobucrlnaaslsoOfptihsetMhaolbarcaonlcohgiiac)a.l
in Macquarie Harbour on the west coast of InMarineInvertebratesofSouthernAustralia. Part ll pp.
725-788. EdsSAShepherdand IM Ihomas. (South Aus-
T2a-s5manmima. iNninleengstmha,llaprreeseprrve^seedntspeacmiomnegnsst, ButrrnaliRan(2G0o0v6e)rAnmcehnectklPirsitnaUnngddbiivbilsiloognriaApdheylaoifdteh)eOpi.stho-
Museum Victoria material sorted from three branchia(Mollusca;Gastropoda)ofVictoriaandtheBass
Straitarea,.south-easternAu.stralia. VictoriaSci-
bottom samples located within the Harbour, enceReports10.1-42
taken during a survey carried out in August Coleman N (2001) lOOl Nudibranchs - Catalogue of
Indo-PacificSeaSlugs(NevilleColeman’sUnderwaterGeo-
-maSrekpetdemobnerth1e99h5e.aTdheshimeelddiainnaglrlosopveeciismewnesl,l GogsrlaipnheircTPMty(I1.t9d8:0S)prSiynsglvcvm4aKt)di.csQuaenedn.pshlyalnodg)enyoftheAgla-
which though now uniformly decoloured still jli.dianene(aOnpSiosctioebtrya6nHc,hi3a2:.5M-o3U6u0sca).ZoologicalJournalofthe
show signs of brownish pigmentation of the KantorYIandSj’.soevAV(2006)M^irmeandBrackishwater
Hancocksorgans. Unfortunately, the shell has cGaatsatlroogupeo.da(KofMRKusSscilaenalintdicadPjreascse^nLttdc:ouMnotrsiceso:w)anillustrated
decalcifiedwithineachspecimen. RudmanWB(1968)'IhreenewspeciesoftheopisUiobranch
family Aglajidae fromNew Zealand. Transactions ofthe
AThceknwroiwtelreidsggeramteefnutlsto Val Stajsic, Margaret Rowe, RuRdoymaalnSoWciRety(1o9f7N2ae)wOZenalMaenlda.noZcohoJlaomgyy.s10C(2h3e)e,s2eJm1a-n2161.881,
AudreyFalconerandLeonAltofffordiscoveringthe agenusofthe Aglaiidae (Opi.sthobranchia, Ga.siropoda).
living specimens of Melanochlamys handrecki and RuPdacmifaincSWciBenc(e192762(1b)),S5t0r-u6c2t.ureand functioningofthe gut
bringingthemtohisattention,tol.conAltoflandPla- intheBullomorpha (Opisthobranchia).Part4,Aglajidae.
tfoorntVyapfiinadgisthfeormpahnoustcorgirpatp.hyT,liainsdpatopeArudarnedysFpaelciceosneirs RuJdoumrannalWofBNa(t2u0r1a0l)HiSsetaorSylu6g,5F4o7r-u5m6.0.(AustralianMuseum:
dedicatedtothememoryofthelateClarrieHandreck Sydney)<http://www.seaslugforum.net>
(1936-2009), who,had hebeenwell enough,would
havegreatlycnjo)TidthetwodaysinMarch2009that
theMarine Research Group, FNCV spent.surveying
thewonderfulmarinefaunaofShallowInlet. Received9September2010;accepted28October2010
References
BurnR(1957)AnewspeciesofOpisthobranchiafromVicto-
ria.VieVictorianNaturalist74,115-117.
One Hundredand OneYears Ago
THETASMANIAN NATURALIST—The October issueofthisjournal contains an excellent article, en-
titled" GuidetotheMolluscaofTasmania,adaptedforYoungStudents,"byMr.W.L. May,whichhasthe
additionaladvantageofbeing illustrated bydrawingsofthirty-threespecies ofTasmanian shells. Asthe
conchologyofVictoriaandTasmaniaisverysimilar,thearticleshouldbeusefultobeginnershere.Copies
ofthejournal canbeobtained from the hon. sec.Tasmanian FieldNaturalists’ Club, Hobart,ata costof
sevenpence(includingpostage).
WW,
From The VictorianNaturalist p. 83, November9, 1909
Vol 127 (6) 2010 235