Notes on the External Anatomy of Nine Pyramidellid Marine Snails (Gastropoda: Pyramidellidae) from Victoria

2007·1.8 MB·English

by  Platon Vafiadis

1
Contributions
Notes on the external anatomy ofnine pyramidellid
marine snails (Gastropoda: Pyramidellidae) from Victoria
Platon Vafiadis
MarineResearchGroup,FieldNaturalistsClubofVictoria
LockedBag3,POBlackburn,Victoria,3130
Abstract
TheliveobservationofninespeciesofpyramidellidmarinesnailsfromVictorianwatershasallowed
a report on their external anatomy. Briefnotes on the family are also provided. (The Victorian
Naturalist124(5),2007,296-305)
Introduction and methods Observations
Recent intertidal records have allowed liv- Odostomiadeplexa(Tate& May, 1900)
ing pyramidellid marine snails from vari- Material: One specimen, sieved intertidal-
ous Victorian localities to be studied. The ly from among mud and Zostera seagrass.
animals have been legally collected by Crawfish Rock, Western Port Bay,
members of the Marine Research Group Victoria, Friday 28 November, 2006.
under permits held from Parks Victoria. Collected by R. Burn. Museum Victoria
They were kept alive in seawater and reference numberFI13533.
examined in this medium under the stere- Shell (Fig. la): The shell is 2.9mm long,
omicroscope, where notes and drawings elongate and smooth, semi-opaque and
were made. Specimens have been pre- very light yellowish-white in colour. The
served in 70% ethanol and lodged in the protoconch is not prominent and appears
Marine Invertebrate Department, Museum insert, and the columella bears one small
Victoria. plication. There is avery narrow, indistinct
umbilicus behind the columellarreflection.
Summary ofspecies examined The operculum is elongateoval, sturdy,and
The higher classification below follows
brownish-yellowwith no spiral markings.
Bouchet and Rocroi (2005). Sub-family Animal (Fig. 2a): The animal is semi-
placements have been guided by the
opaque white, with the cephalic tentacles
arrangement given in Schander et al. semi-translucent white and lightly tinged
(1999). lemon-yellow. There are occasional fine
SuperfamilyPyramidelloidea cream-white spots on the dorsal foot and
FamilyPyramidellidae mentum; on the central head behind the
SubfamilyOdostomiinae eyes these are densely aggregated, forming
Odostomiadeplexa(Tate&May, 1900) a whitish patch. The cephalic tentacles are
Linopyrgapascoei Angas, 1867) long and delicate, flattened along their
(
Linopyrgaportseaensis (Gatliff& Gabriel, length, each bearing a small semi-translu-
1911) cent tentacular pad at the outer end. The
PseudoskenelladepressaPonder, 1973 eyes are black and the mentum is small,
smoothly rounded with no notch. The
SubfamilySyrnolinae
SyrnolabifasciataTenisonWoods, 1875 extended foot is two-thirds to three-quar-
SuSbyfranmoillaytTinucrtbaonAinlglaisn,ae187 wteirdseorfctehnetrashlellyl, alenndgtbhl,unbtil-ylorboeudndanetderpioosrtley-,
Cingulinaspina(Crosse&Fischer, 1864) riorly. The sole bears a very faint cleft in
Pyrgiscusfuscus(A.Adams, 1853) its midline, commencing at mid length and
Turbonillabeddomei(Petterd, 1884) extending posteriorly but not reaching the
end. The extended animal sits relatively
low in the dorso-ventral plane, and crawls
with a smooth, gliding motion.
296 TheVictorian Naturalist
Contributions
sFciagl.e)1,.aD).raOwdionsgtsomoifashdeelpllsex(saca(lTeatlein&esMiandyi,ca1te9001).0(mprmo)toacnodncphrvoitoecwoendchfsroamboavbeovee)a,chb)s.heLlilno(npoytrgtao
p&asGcaoberiie(lA,nga19s1,1)1.86d7)).(PpsreoutdoocsokncehnevlileaweddepfrreosmsasidPeonadnedr,abo1v9e7)3, c()p.rLoitnoocpoynrcghavpioertwseedaefnrsoism(aGbaotlvief;f
retractedoperculumvisibleinsideaperture). '
Vol. 124 (5) 2007 297
Contributions
Distribution: It is found from Victoria to
South Australia, including Tasmania
(Cotton, 1959).
Linopyrgapascoei(Angas, 1867)
Material: One specimen, intertidally, from
West Cape, Cape Conran (just east ofboat
ramp), Victoria, 1 March, 2006. Collected
by R. Bum. Museum Victoria reference
numberFI13531.
mm
Shell (Fig. lb): The shell is 5.5 long,
sturdy and opaque white. The whorls bear
axial ribs and many microscopic spiral
striae, with the former fading anteriorly on
the body whorl. Laseron (1951) observed
the axial ribs traversing the length of the
body whorl, but Angas (1867) described
them as fading anteriorly. The columella
bears a plication and the protoconch from
above appears insert. No observations have
beenmade on the operculum.
Animal(Fig. 2b): Theanimalwas sluggish
and microscopic examination has not
occurred. Observations here are restricted
to those of the animal being white, with
black eyes situated near the midline.
Hedley (1916) offers a brief description
and diagram ofthe living animal, noting it
to be uniform cream in colour with black Fiingd.ica1te(co1n.t0’dm)m.)Draanwdinpgrsotoofcosnheclhlss a(sbcoavlee leiancehs
eyes, with the animal creeping away from shell (not to scale), e). Syrnola bifasciata
light. TenisonWoods, 1875. f)- SyrnolatinctaAngas,
Distribution: It is found in New South 1871. g). Cingulina spina (Crosse & Fischer,
Wales (Jansen, 1995), with this record 1864). h). Pyrgiscusfuscus (A. Adams, 1853)
e(xBtuemn,dipenrgs.tchoemrma.n)g.e to eastern Victoria d(oCmaepie(CPoetntreardn,s1p8e8c4i)m(eBnl)a,nkie).tBTuarybosnpieclilmaenb)e.d-
Linopyrga portseaensis (Gatliff & occurred. It hasbeen photographed extend-
ed, and, on this basis, limited observations
Gabriel, 1911)
Material: One specimen, intertidally, from are offered. The animal is white, the
cephalic tentacles are relatively short and
West Cape, Cape Conran (just east ofboat
somewhat triangular in outline, the eyes
brnayummpRb).e,rBVuFirIctn1o.3ri5Ma3,u0.s1eMuamrcVhi,ct2o0r0i6a. rmCeomflelreecntceed taarnuetmebrliiaosrcklfooaonntgd. saTinhtdeuateeenxddtceeonnfdtrstahlelbye,myetonhnetdummetnhi-es
Shell (Fig. lc): The shell is 3.4 long, notchedcentrally andlaterallyexpanded.
opaque white and more slender than L. Bum (unpubl.) has observed and figured
pascoei. The whorls bear axial ribs and
many microscopic spiral striae, the latter acoslpleecctiemdenfrofomLiEnnotpyerrgoamocfr.pphoartasleageanesiast
continuing to the anterior aspect of the
Point Danger, Torquay, Victoria, noting a
body whorl. The columella lacks a plica-
white animal, with his figure agreeing well
tion and the protoconch is angled, partially with the overall form shown in the photo-
engulfed by the succeeding teleoconch
graph ofFig. 2c. Burn’s (unpubl.) figure
wnhootrcll,eaar.ndNosoombeswehravattiwoonrsnhsaovethbaetednetmaialdies slehnogwtshaofmeitnstmuimdltihnaet.isBugrrnoo(vuendpuabllo.n)ghtahse
ontheoperculum.
also collected Linopyrga cf. portseaensis
Aannidmmailc(rFoigs.co2cp)i:cTheexaamniinmaaltiwoans shlausggniosht intertidally from Point Danger Torquay on
298 The Victorian Naturalist
Contributions
Vol. 124 (5) 2007 299
Contributions
Amphibolis seagrass, and also intertidally Australia (Edgar, 1997), it seems feasible
from PointLonsdale onalgae. thatP. depressamayalsooccurthere.
Distribution: It is found in Victoria and SyrnolabifasciataTenison Woods, 1875
Tasmania (Cotton, 1959), and probably Material: Two specimens, sieved inter-
alsoinNew SouthWales (Laseron, 1951). tidally from among mud and Zostera sea-
Pseudoskenella depressa Ponder, 1973 grass, Crawfish Rock, Western Port Bay,
Material: Two specimens, on the poly- Victoria, Friday 28 November, 2006.
chaete tube worm Galeolaria caespitosa Collected by R. Burn. Museum Victoria
Lamarck, 1818 in the mid-littoral zone, reference numberFI13532. mm
Waratah Bay, Victoria, 19 September, Shell (Fig. le): The shells are 4.2 and
2005. Collected by P. Vafiadis. Museum 4.0 mm long, white, elongate, semi-opaque
VictoriareferencenumberF1 13327. and smooth. The protoconch is largely
Shell (Fig. Id): The shells are thin, concealed by the first teleoconch whorl.
smooth, flatly globose, colourless, trans- The teleoconch whorls bear two brown
parent, and 1.0 mmwide. The apices ofthe spiral bands, one centrally and the other
shells appear insert. The sutures are well just above the suture, with a third band on
defined, the aperture is ovate and the the body whorl. The columella has one
umbilicus shallow. There is a thin, glassy prominent plication and there is a triangu-
operculum. lar umbilicus. The operculum is translu-
Animal (Figure 2d): This has been cent and yellow-brown. On preservation,
described and figured by Ponder (1973) the retracted animals have left seven-
and also noted by Bum (1974a) and Burn eighths ofthebodywhorl vacant, exposing
and Bell (1976), the latter having found it areas ofwhite calcareousthickening onthe
among G. caespitosa collected from eight innerdorsal bodywhorl.
different Victorian localities from Portland Animal (Fig. 2e): The animal is semi-
in thewestto ShallowInletinthe east. The opaquewhite, sparsely dottedwith spotsof
animal is semi-opaque white, with semi- cream-white on the cephalic tentacles,
translucent white cephalic tentacles. It has mentum and dorsal foot; on the head
a yellowish mantle organ flecked with behind each eye these cream-white spots
brown spots, visiblethroughthe dorsum of aredensely aggregated, andextendposteri-
the shell. Brownvisceral organs arevisible orly out of view under the anterior shell
beneaththe earlywhorls. The cephalic ten- margin. The cephalic tentacles are broad,
tacles each distally bear a small, transpar- flattened along their length, and taper to a
ent tentacular pad. The eyes are black and blunt point, without tentacular pads. The
the mentum is not notched. The proboscis eyes are black and the prominent mentum
was not seen everted, but Ponder (1973) tapers outwards distally, and is widely
rwehpeorntsfuiltltyoebxetetnhdreede.tiTmhees dtohresashlelplrolpeondgit-h igsrohoevleddinalfornogntthoefltehnegtahntoefriiotrs mfiodoltinwch.eInt
um bears a white transverse ridge and the crawling. The extended foot is about three
sole a faint posterior midline cleft. The quarters ofthe shell length and the sole is
extended foot is equal to or slightly longer broader anteriorly and bears no clefts or
than the shell. The animal is active, crawl- visible openings. The animal crawls with a
ing with a smooth, gliding motion. The smooth, glidingmotion.
footdoes not protrudebeyondthe posterior Bum (unpubl.) has figured and recorded
shell when crawling. It feeds parasitically this species alive from among Caulerpa
aonndithsahsosatl,stohebeteunbefwoounrdmoGn.caaelsgpaoetiasnad, waligtahetahte Paobionvte,LoenxscdeapltethVaitcttohreiam,eangtrueeminogf
understones (Ponder, 1973). the Point Lonsdale specimendoes nottaper
Distribution: It is found in eastern outwards at its distal end and is not shown
Australia from Queensland to Victoria to be prominently grooved along the length
(Ponder, 1973), including Tasmania (Bum of its midline. Burn (unpubl.) has also
and Bell, 1976). Because G. caespitosa recorded this species alivefrom PortAlbert,
also occurs in SouthAustraliaandWestern Victoria,andfromNewSouthWales.
The Victorian Naturalist
300
DistributionmapsofEuastacusspecies,a.Euastacusarmatus. b.Euaslacusbidawalus. c.Euastacus
bispinosus. d.Euastacusclavtoni. e.Euastacusdiversus. f.Euastacuskershawi. g. Euastacusvanga.
h. Euastacusvarraensis.
Distribution maps of Euastacus species,
i. Euastacus crassus. j. Euastacus woiwuru.
k.Euastacusneodiversus.

. .
Distribution maps ofEngaeus species, q. Engaeusphyllocercus. r. Engaeusstrictifrons. s. Engaeus
tuberculatus. t.Engaeusvictoriensis. u.Engaeusaffinis.v.Engaeusaustralis.
DistributionmapsofEngaeusspecies,a.Engaeuscunicularius b.Engaeuscurvisuturus c.Engaeus
cymus. d. Engaeusfultoni. e. Engaeus urostrictus. f. Engaeus merosetosus. g. Engaeus orientalis.
h.Engaeushemicirratulus.
Distribution maps ofEngaeus species, i. Engaeus karnanga. j. Engaeus laevis. k. Engaeus lyelli.
I. Engaeus mallacoota. m. Engaeus quadrimanus. n. Engaeus rostrogaleatus. o. Engaeussericatus.
p.Engaeussternalis.

Contributions
Fig. 2. Headand anterior footviews. Notto scale relativeto each other. Dotted lines on thecephalic
tentaclesrepresentaventraledgevisiblethroughthetentacle. Dotted linesinPseudoskenelladepressa
indicatethetransverseridgevisiblethroughthementum. Key:af-anteriorfoot;ct-cephalictentacle;e
-lefetyec;epmhal-imcetnetnutamc;letpas-itnednitcaactuelda,r(paa)d.;Otdro-sttroamnisavedrseeptreixdage;(Ttactse-&trManasyv,ers1e90c0r)o,ss(b)s.ecEtnitoinretharnoiumgahlthoef
Linopyrgapascoei (Angas, 1867), (c). Entire animal ofLinopyrgaportseaensis (Gatliff& Gabriel.
1911),(d).PseudoskenelladepressaPonder, 1973.
Distribution: It is found in south-eastern February, 2004, by A. Falconer. Museum
Australia from central New South Wales to VictoriareferencenumberF113328.
South Australia, including Tasmania Shell (Fig. If): The shell is cream white,
mm
(Jansen, 1995; Cotton, 1959). opaque, smooth, and 6.9 long. The
protoconch is smooth and heterostrophic.
Syrnolatincta Angas, 1871 The teleoconch whorls are smooth except
Material: One specimen, collected inter- for microscopic longitudinal growth
tidally at Blanket Bay, Victoria, 15 scratches, and patterned by faint broken
Vol. 124 (5)2007 301