Systematic review and functional morphology of the mangrove snails Terebralia and Telescopium (Potamididae; Prosobranchia)

50 Pages·1991·19.3 MB·English

by  Richard S Houbrick

MALACOLOGIA, 1991,33(1-2): 289-338
SYSTEMATIC REVIEW AND FUNCTIONAL MORPHOLOGY OF THE
MANGROVE SNAILS TEREBRALIA AND TELESCOPIUM
(POTAMIDIDAE; PROSOBRANCHIA)
Richard S. Houbrick
DepartmentofInvertebrate Zoology, National Museum ofNatural History,
Smithsonian Institution, Washington, D.C. 20560 U.S.A.
ABSTRACT
Diagnoses of the genera Telescopium Montfort, 1810, and Terebralia Swainson, 1840, are
made, based on conchological and anatomical characters. Telescopium telescopium (Linné,
1758) istheonly living memberofthegenus. Three Recent Terebraliaspecies are recognized:
Terebralia palustris (Linné, 1758), Terebralia sulcata (Born, 1778) and Terebralia semistriata
(Mörch, 1852). Complete synonymiesand descriptionsare presented foreach genus-level and
species-level taxon. Cerithium crassum Lamarck, 1822, and Strombus semistriatus Röding,
1798,aredeterminedtobenominadubia. Shells,radulaeandanatomicalfeaturesaredescribed
andcompared, and intraspecificvariabilityisnoted. Bothgeneradatefromthemid-Tertiary, and
mostlivingspecieshavefossil recordsextendingbacktotheMiocene. Bothgeneraareconfined
today to the Indo-West Pacific. The ecology, life history, fossil record and geographical distri-
bution ofeach species are presented. Speciesof both generaareamphibioussurface-dwellers
ofmuddysubstratesin mangroveforests, and havereducedctenidia. Mostarealgal-detritivores
and have ataenioglossate radula, complex stomach and long crystalline style. The radula and
buccal mass of Telescopium are very small, but the snout is extremely long. The radula and
buccal mass of Terebralia species are robust and large. Terebralia palustris is unusual in
undergoing a radulartransformation betweenjuvenile and adult stages thatcorrespondstothe
trophic dimorphism between the two stages: juveniles eat detritus, whereas adults eat fallen
mangroveleaves.Speciesofbothgeneraaregonochoristicwithaphallatemalesandhaveopen
palliaigonoducts. Thepalliaioviductof Telescopiumishighlycomplex, comphsingfourlaminae
andverylarge,transverseglandularridgesadjacenttotheoviductalgroove.Thepalliaioviducts
of Terebralia species are unusual among those of cerithioideans in having medial fusions.
Terebralia males produce elaborate, crescentic spermatophores sculptured with many trans-
verse keels. Spawn masses of both genera are deposited with the aid of a bulbous ovipositor
locatedontherightsideofthefootandcompriselong, irregulargelatinoussthngsfilledwithvery
small egg capsules. Theovipositorof Terebraliaspeciesextendsdeep intothefoot, forming an
innerglandularchamber of ectodermal origin, which is thought to secrete the outercoat ofthe
gelatinous sthng during spawn deposition. Species of both genera have free-swimming larval
stages.ThesubfamilyBatillariinaeisexcludedfromthe Potamididaeand raisedtofamilial rank.
The genus CerithideaSwainson, 1840, isconsidered closely related to Telescopiumand Tere-
bralia.
Key Words: Potamididae, Telescopium, Terebralia, systematics, anatomy, reproductive biol-
ogy, ecology, mangroves.
INTRODUCTION scopium telescopium (Linné, 1758) repre-
sents a now monotypic genus.
One of the most conspicuous elements The taxonomy of Potamididae H. & A. Ad-
of the malacofauna of the vast mangrove ams, 1854, is in disarray because earlier au-
swampsofthe Indo-West Pacificprovinceare thors relied chiefly on shell characters in their
the ubiquitous potamidid snails of the genera classifications and did not set clear limits to
Telescopium Montfort, 1810, and Terebralia higher taxa. They were also unaware of the
Swainson, 1840. Terebralia comprises three significant anatomical differences between
Recent species, Terebralia palustris (Linné, the Cerithiidae Férussac, 1819, and the Pot-
1758), Terebralia sulcata (Born, 1778) and amididae, and commonly referred many pot-
Terebralia semistriata (Mörch, 1852); Tele- amidid taxatothe Cerithiidae; moreover, ear-
289
— —
290 HOUBRICK
lier workers did not understand the anatom- numerouswhorls ofthevisceral masswithout
ical differences between the two subfarilies damaging the thin mantle tissue, especially
thought to comprise Potamididae (Potamid- around the palliai gonoducts. Extracted snails
inae H. & A. Adams, 1854, and Batillaninae were kept alive in aquaha and finger bowls.
Thiele, 1929).Genus-leveltaxafromeachpot- No adult males of Terebraliapalustrisor Tele-
amidid subfamily were frequently mixed with scopium telescopium were found.
one another and with other cerithiid taxa in It is very difficult to remove these snails
varying combinations that included nomina of from their strong shells successfully without
extinct higher taxa. The resultant entangled injuring and destroying tissues; moreover,
higherclassification is misleading and engen- damaged or injured snails secrete great
ders frustrating searches for taxa in the older quantities of mucus, which hinders dissection
literature. and fixation. Thus, it was not possible to pre-
Terebralia and Telescopium species are pare and examine numerous individuals in
large prosobranchs that occur in great num- the short time spent in the field, but sufficient
bers and frequently dominate the surface of material was examined for comparative dis-
the muddy substrates of mangrove forests. It sections. Animals were relaxed in 7.5%
istherefore surprising that so little is known of MgClg solution for anatomical study and dis-
theiranatomy, reproductive biology or life his- section under a Wild M-8 dissecting micro-
tories. Although a number of ecological stud- scope. A solution of methylene blue/basic-
ies on migratory movements and vertical dis- fuchsin was used to enhance anatomical
tribution in the mangrove habitat have been features. Tissues were fixed in Bouin's solu-
published, there has been no attempt com- tion in seawater or in 10% seawater formalin
prehensively to integrate these observations andwere sectioned with a razorblade. Whole
and other anecdotal information. So little is animals were too large for histological sec-
known about the soft anatomy and reproduc- tioning, but selected organs and tissues were
tive biology of these large potamidids that it embedded in paraffin, sectioned at 7 ixm, and
has been impossible to establish a good data stained with Harris' hematoxylin and eosin
base for character analysis; thus, the phylog- or Mallory's triple stain for histological exam-
eny and systematic standing of these taxa in ination. Photomicrographs of sections were
relation both to other potamidids and to other made with a Zeiss Photomicroscope III. Tis-
cerithioidean families has been unclear. It is sueswerecritical pointdried andthese, along
the goal herein to rectify this situation. with radulae and spermatophores, were ex-
amined with a Zeiss Novascan-30 scanning
electron microscope. Voucher specimens
MATERIALS AND METHODS havebeendeposited inthe USNM. Preserved
museum specimens of species from other
geographic regions were also used for study,
All three living species of Terebralia were but most were too poorly fixed for careful dis-
studied in thefield and in the laboratory. Pop- section.
ulations of Terebraliasulcatawere studied for The discussion of anatomical characters
ten days in the New Territories of Hong Kong of each genus and the final discussion of pot-
and at the University of Hong Kong. Work on amidid anatomy should be understood with
Terebralia semistriata and Terebralia palus- reference to my paper on cerithioidean phy-
tris was conducted for five days at Magnetic logeny (Houbrick, 1988).—
Island andTownsville, Queensland, Australia. Abbreviations: AMNH—American Museum
The anatomy of both Terebralia palustris, the of Natural History; AMS The Australian Mu-
type species of Terebralia, and of Terebralia seum, Sydney; ANSP—Academy of Natural
sbuylcaatbariiesfddeessccrriipbteidoninofsoTmeerebdretaaliila, sfeomlilsotwreid- sSceiuemnce(sNaotfurPahlilaHdiesltoprhyi)a;; BCMNNHHM——BFriietlisdh MMuu--
ata. Observations and dissections of live seum of Natural History; DMNH—Delaware
Telescopium telescopium, the type of the ge- Museum of Natural History; FSM—Florida
nus by tautonomy, were conducted at Mag- State Museum, Gainesville; MCZ—Museum
netic Island, Queensland, Australia. Living of Comparative Zoology; MNHNP—Museum
USNM—
ardeumlotvsepdecfirommentsheiorfsahllelolfstbhyescerasckpiencgietshewmerien NUantiitoendalSdt'aHtiesstoirNeatNiaotnuarlellMe,usPeaurims;; WAM
a large vise. Animals were extracted from Western Australian Museum; ZMA Zoo-
theirshells, andcarewastakentoremovethe logisch Museum, Amsterdam.
REVIEW OF TEREBRALIA AND TELESCOPIUM 291
SYSTEMATICS paniloidea. A numberof Italian Tertiaryfossils
POTAMIDIDAE H. & A. ADAMS, 1854 lacking apertures were allocated to Tele-
TELESCOPIUM MONTFORT, 1810 scopium by Sacco (1895), who noted that
they differed sufficiently from Recent Tele-
Telescopium Montfort, 1810:438 (Type spe- scopiumtowarrantestablishmentofasubge-
cies, by od: Telescopium indicatorMont- nus, Telescopioidea Sacco, 1895, to accom-
fort, 1810 [= Trochus telescopium Linné, modate them. Sacco (1895) noted that they
1758, type species by tautonomy]). more closely resembled living Campanile
Tryon, 1882:250; Cossmann, 1906:124- symbolicum than they did Telescopium; ex-
125; Wenz, 1940:743. amination of these taxa confirms that they
Diagnosis: Shell very large, thick, conical, should be regarded as members ofthe Cam-
with numerous flat-sided whorls sculptured panilidae. Authors such as Adams & Adams
with spiral grooves; shell basewith concentric (1858:291) frequently included Campanile
cords and deep channel around columellar symbolicum Iredale, 1917 (cited as Cerithium
pillar. Aperture narrowly ovate, tangential laeve Quoy & Gaimard, 1834) in the genus
Telescopium.
(perpendicular) to shell axis with twisted,
channeled columella, and outer lip curved to- Fragmentary fossils of species of Campa-
ward centrally placed, short siphonal canal. nile(Campanilidae)andtheextinctpotamidid,
Operculum corneous, circular and multispiral Vicarya Archiac & Haime, 1854, are com-
with central nucleus. Lateral tooth with broad monly assigned to Telescopium by authors.
lateral lamella. Snout very long with small Shuto (1978:116, pi. 15, fig. 4) referred Pot-
buccal mass and very small taenioglossate amidesjogjacartense (Martin, 1914) to Tele-
radula. Rachidian tooth ovoid with broad cen- scopium, but judging from his illustrations of
tral cusp. Mantle with siphonal light-sensory the specimen, it is doubtful that it should be
organ (palliai eye). Ovipositor on right side of included in the genus.
foot in females. Palliai gonoducts completely Although many reports of fossil Tele-
open, highly complex. Zygoneurous nervous scopium in the literature are erroneous and
system. Eggcapsulesdeposited ingelatinous based on fragments of other taxa, numerous
strings. fossils of Telescopiumfrom Cenozoic depos-
its in East Africa, Indonesia and the Philip-
Remarks: Telescopium was thought to date pines are either conchologically conspecific
fromtheLateCretaceous(Turonian) byCoss- with Recent Telescopium telescopium, or
mann (1906:123), but most of the fossils at- very closely related to it.
tributed to this genus are campanilids. The Allan (1950:86) included Telescopium in
earliest species that appears to belong to the family Telescopiidae, a name he substi-
Telescopiumasnow understood isa Miocene tuted for Potamididae without giving any rea-
fossil, Telescopium pseudobeliscus (Grate- sons or comment, but there is no justification
loupe, 1832). Recent Telescopiumis a mono- for this name change, and Telescopiidae
typic genus. The genus appears never to must be considered a synonym of Potamid-
have been species-rich, but some fossil spe- idae. In the older literature, Telescopium is
cies have been described. sometimes cited as asubgenusof Potámides
Telescopium telescopium and Campanile Brongniart, 1810 (see Tryon, 1882:250-251)
symbolicum Iredale, 1917, have convergent or as a synonym of Pyrazus Montfort, 1810
shell morphologies and were placed in the (see Adams & Adams, 1858:291), which is a
samegroupin someoftheoldermonographic batillahid.
literature. The shells of many extinct Campa-
nile species also resemble Telescopium, but Telescopium telescopium (Linné)
recent studies have shown that the campa- (Figs. 1-6)
nilid group constitutes a superfamily of its
own (Houbrick, 1989). TelescopioideaSacco, Trochus telescopium Linné, 1758:760 (Holo-
1895:56 (Type species, by o.d.: Cerithium type: Linnaean Collection, London; Type
charpentieriBasterot, 1825) and Campanilop- locality herein selected: Ambon); Linné,
s/'sChavan, 1948 (Typespecies, byo.d.: Cer- 1767:1231; Dodge, 1958:204-205.
ithium ceres Orbigny, 1847) were proposed Cerithium telescopium Bruguiére, 1792:483;
as subgenera of Telescopium, but both Kiener, 1841:88-89, pi. 28, fig. 4; Kobelt,
should be excluded from it tDecause their re- 1898:57, plate 12, fig. 1.
spective type species are members of Cam- Telescopium indicator Montfort, 1810:438,
292 HOUBRICK
figure (in part; Type notfound; Montfort's authors and a Pyrazus species. The figure
figure, a Pyrazus species, here selected references for Telescopium fuscum Schuma-
to represent lectotype). cherarethe sameas Linné'sfor Trochustele-
Telescopium fuscum Schumacher, 1817;233 scopium. Telescopium mauritisi Butot, 1954,
(Type not found; Schumacher's figure isbasedonaworn geronticspecimenof Tele-
reference to Buonanni, 1709, here se- scopium telescopium (see discussion below).
lected to represent lectotype); Boettger,
1890:167. Description
Potámides (Telescopium) telescopium K.
M1a8r9t7in:,1801-818841:;145,Kon3i2n8g,sb3e4r8g;er,Mart1e9n1s5,: tSrhoeclhlo:idS,herlela(cFhiign.g1)13v0erymmlargine,lseonlgitdh,,c5o0nicmalm-
in width, and comprising 12 to 16 flat-sided
446; Lischke, 1914:259; Oostingh, 1923:
75; Benthem Jutting, 1929:86; Rensch, whorls with an apical angle of 30-36 de-
grees. Protoconch unknown. Early whorls
1934:339.
sculptured with beaded spiral cord at suture
Telescopium telescopium K. Martin, 1899:
and with two smooth spiral cords (Fig. 1H).
212208., 1p3i.7;3R3,egtfiegrs.en5A0l9t,ena5,091a9;411:91139-:1944;, Adult whorls sculptured with three large flat
spiral cords and one narrow one, and with
Wissema, 1947:46; Butot, 1954:10; Ben-
them Jutting, 1956:439-441, figs. 100, Smpiicrraolscocpoircd,s csoloamberatli,meaxsialdisstarpiapeea(rFiing.g 1Iw,iJt)h.
108; 1959:105-106; Cernohorsky, 1972:
age or erosion. Suture weakly defined. Body
61, pi. 13, fig. 6; Brandt, 1974:196, pi. 15, whorl carínate in juveniles but expanded and
Telefsigc.op6i1.um mauritsi Butot, 1974:7-12, pis. cborrodasd ainndadduletesp. Schhealnlneblasaerowuintdh ccoolnucmeenltlrairc
T1,ypfiegs.l3o,ca4l;it2y,: fiPgsu.lo2, 3Pa(nHaoiltoatny,pe:SZuMnAd;a pillar. Aperture small, narrow, nearly tangen-
Strait, Indonesia); Benthem Jutting, tial (perpendicular) to shell axis, with well-
1959:105. rounded outer and basal margins. Outer lip
thin, concave; basal lip hook-like, curved to-
wardssiphonalcanal. Columellaconvex, hav-
Synonymic Remarks. Specimens of this dis-
ing callus with thick, channeled, twisted fold
tCionlclteicvte,iosnpeicniLeosndococnuranidn ibnotthhet"hMeuLsienunmaeUaln- extending into shell aperture and up columel-
ricae" of the Uppsala Collection (Dodge, laraxisfor length ofshell (Fig. 1L). Shell color
1958:204-205). According to Dodge (1958), uniform dark reddish-brown to black, with
who presented a lengthy commentary on the whitish to light brown columellar callus.
types and Linnaean figure references for this Operculum (Fig. 1M,N)corneous,small,cir-
cular, multispiral (9-17 whorls), with central
species, no question has ever been raised as
nucleus, transparent and fringed at margins.
to the identity of Telescopium telescopium,
and its synonymy is "unimpeachable." He be- External Anatomy: Animal black-gray with
lieved that the specimen in the Linnaean col- dirty-white sole. Snout large, long (Fig. 3B,
lection in London should be accepted as sn), having pair of short broad cephalic ten-
Linné's probable type specimen, and con- tacles, each with tiny black eye at peduncular
I
cur. Although Bruguière (1792) cited Cerith- base. Tentacles sharply constricted at tips.
ium telescopium without attributing author- Snout dorso-ventrally compressed, lined with
ship to Linné, he did not intend to describe it many deep transverse wrinkles (Fig. 2B,C),
under his own authorship, for he clearly very supple, extensible for considerable dis-
statedthat he merelywastransferring Linné's tance. Snout tip (Fig. 2B) with thick, whitish,
specimen (species) from Trochus to Cerith- fleshy pad having vertical slit-like mouth (Fig.
ium (Bruguière, 1792:484). Mostof Montfort's 2C). Foot large with whitish sole having many
(1810) figure references for Telescopium in- branching, transverse furrows (Fig. 2D). Left
dicatoragree with Linné's type specimen and lateral and ventrolateral sides of foot each
figure references for Trochus telescopium, with deep, rounded groove (Fig. 3, llg, vg);
but Montfort's (1810: figure, p. 438) own fig- groove strongly developed on left side. Ante-
ure of Telescopium indicator definitely does hor mucous gland opening a narrow, deep,
not represent Telescopium, but appearsto be slit (Fig. 2D; 3B, amg) extending halfway
a Pyrazus species; thus, his concept of Tele- around sides of sole and heavily ciliated
scopium indicator appears to be a mixture within (Fig. 2E). Grooveemerging fromexhal-
based upon the Telescopium figures of other ant siphon long, deep, highly ciliated in both
REVIEW OF TEREBRALIA AND TELESCOPIUM 293
3-
FIG. 1. Telescopium telescopium, shells and operculum. A-D, apertural, dorsal, side and anteriorviews of
aandtuelrtisohrelvliferwosmofCabiardnls,yQeuroedeends,lagnedr,onAtuisctrsahleilal;f9r8o.m9Hxal4m7a.h3emram,(MoUlSuNcMca7s9;5120331).xE-51G,mamper(tuUrSalN,Mdo8r3s7a1l0a7n)d.
H,juvenileshellfrom Cebu, Philippines;40.5 x 20 mm (USNM419345). I-K, apertural, dorsal andanterior
viewsofuneroded,cleanedshellshowingsculpturaldetails,from BatangasBay, Luzon, Philippines;86.5 x
37.7 mm (USNM 846507). L, shell sectioned through axis showing columellarpillarwith weak interiorplait.
M, N, attached (M) and free (N) sides of operculum; 11.9 mm diameter.
,sexes, running down right side of foot (Fig. separating inhalant siphon area from rest of
eg) in nnales, ending at edge of sole; In mantle edge; ventral half of mantle edge
fennales, ending,at oval, sooty-colored, warty smooth. Edgeofinteriorofrightsideofmantle
ovipositor (Fig. ovp) near sole margin. with thin glandular line of unknown function.
Ovary pale yellow; testis orange. Mantle dirty Inhalant siphon thick, and interior edge with
white. Dorsal half of nnantle ,edge with small, one or two orange-pigmented spots, each
weak,wart-likepapillae (Fig. mp) andwith surrounding black, pit-like light-sensitive or-
median cleft (Fig. 3B, mc) about 5 cm deep, gan (eye) containing lens.
294 HOUBRICK
w w
^A
ovp
^
REVIEW OF TEREBRALIA AND TELESCOPIUM 295
FIG. 3. Telescopiumtelescopium. anatomicalfeatures.A, rightsideoffemaleshowingelongatesnout, large
foot, ciliatedgrooveandovipositoronsideoffoot. B, anteriorviewofhead-footshowing mantleedge, head,
snoutand sole; noteopeningofanteriormucousgland (amg) alongedgeofsole. C, central nervoussystem
showing relationshipof ganglia and long supraesophageal connective (sec); visceral ganglion and visceral
loop not shown. D, individual ctenidial filaments from anterior (left) to posterior (right) mantle cavity, amg,
opening to anterior pedal mucous gland; eg, ciliated groove; cm, columellar muscle; cpc, cerebral-pedal
connective; d, dialyneury; exh, exhalant siphon; leg, left cerebral ganglion; llg, left lateral groove; Ipl, left
pleuralganglion; m, mouth;mc, manticavityopeningorinhalantsiphon; mp, mantlepapillae;op,operculum;
ovp, ovipositor; pn, palliai nerve; rcg, right cerebral ganglion; rpg, right pedal ganglion; rpl, right pleural
ganglion; s, sole; sbc, subesophageal connective; sbg, subesophageal ganglion; sec, supraesophageal
connective; sn, snout; spg, supraesophageal ganglion; st, statocyst; t, tentacle; vg, ventral groove; z,
zygoneury.
2F, ct). Hypobranchial gland white, narrow, Alimentary System: Snout tip with thick,
about one-half length of rectum, and secret- fleshy, ovate pad surrounding vertical slit-like
ing great sheets of mucus over ctenidium mouth. Pair of hook-like extensions (Fig. 2C)
and rectum. Rectum very large, wide, with in- at top edge of oral tube. Pair of small jaws in
terior epithelium forming deep transverse sides of oral tube. Radula (Fig. 4A-D) very
ridges and complex folds, producing large small, fragile, short, about 5 mm long, com-
surface area. Anus located well behind front prising 80 rows of teeth, and about 3.3 per-
of ctenidium. Palliai gonoducts open, com- cent of shell length. Rachidian tooth (Fig.
prising two major laminae, and parallel with 4B,C) oval, taller than broad with convex an-
rectum. terior end and long, dagger-like basal plate;
296 HOUBRICK
FIG. 4. Telescopiumtelescopium. scanning electron micrographsofradula. A, mid-sectionofradularribbon
with marginals spread open; bar = 200 ^.m. B, detail of lateral and rachidian teeth; bar = 80 [xm. C, half
row of radula showing elongate basal plate of rach.idian tooth; bar = 90 ixm. D, detail of marginal teeth
showing flange on outer marginal tooth; bar = 40 E, half row; bar = 100 \im.
cutting edge with spoon-shaped central cusp cal mass very small, at snout tip. Small,
flanked on both sides by three or four small paired, tubular salivary glands (Fig. 5A, sgd)
denticles. Lateral tooth (Fig. 4B) longer than beginning well anterior to nerve ring, each
broad, having long, wide, rectangular basal looping and folding along sides of buccal
plate, pointed posteriorly, and with slightly mass, and opening into anterior dorsal oral
flaring outer side; cutting edge with large cavity. Anterior esophagus (Fig. 5A, eso) a
spatulate central cusp, two inner denticles simple tube having dorsal food groove, twist-
andthree outerdenticles. Marginal teeth (Fig. ing at nerve ring, and becoming slightly wider
4C,D) with long narrow shafts and hook-like behind it. Mid-esophagus (Fig. 5B) long, mod-
tips having long, pointed central cusps. Inner erately wide, with large dorsal, ventrally lo-
marginal tooth with four inner denticles and cated food groove (Fig. 5B, df), but not de-
three outer denticles, outer marginal tooth veloped into esophageal gland. Posterior
lacking outer denticles, but with wide flange esophagus very long, becoming narrower
(Fig. 4D) along outerside of tooth shaft. Buc- posteriorly, entering right lateral side of pos-
REVIEW OF TEREBRAUA AND TELESCOPIUM 297
bm
vf
25mm
ovg
4mm
FIG. 5. Telescopium telescopium, anatomical features. A, representation of dorsal lateral view of buccal
mass, dorsal epithelium partlyopened to expose radula. B, cross-section through mid-esophagus showing
dorsalfoodgrooveandcartilage-liketissueliningbothsidesofesophagealcavity. C,cameralucidadrawing
ofcentral part of palliai oviduct. D, schematic drawing of palliai oviduct, ant, antehor partof palliai oviduct;
ag, albumengland;bm, buccalmass;c,cartilaginoustissue;eg,capsulegland;df,dorsalfoodchannel;eso,
esophagus; It, lateral lamina; ml, medial lamina; osb, opening to spermatophore bursa; osr, opening to
seminal receptacle;ov, coelomicoviduct;ovg, oviductalgroove; prd, parallel ridges; r, radula;sb, spermato-
phore bursa; sgl, outer sperm gutter; sg2, inner sperm gutter; sgd, salivary gland; sr, seminal receptacle;
vf, ventral food channel.
terior part of ston^iach. Stomach very large, mantle cavity to level of pericardium. Crystal-
elongate, about one and one-half whorls and line style very long, club-shaped at gastric
comprised of three chambers: posterior sort- shield.
ing area with large ridge-like central pad and
broad sorting area comprised of many small, Reproductive System: Female palliai oviduct
transverse, epithelial folds; deep, transverse (Fig. 5C,D) long, comprising two complex,
channelwithcentrallylocatedcuticulargastric major laminae; lateral lamina (Fig. 5C,D, II),
shield havingdenticulatemargin; anteriorpor- fused on one side to mantle wall, and medial
tion of stomach long, tubular, consisting of free lamina (Fig. 5D, ml). Medial lamina edge
very long style sac and opening to intestine. trifúrcate, comprising three parallel minor
Style sac very long, adjacent to intestine, but laminae and two ciliated sperm gutters (Fig.
separate from it, reaching anteriorly as far as 5C,D sg1, sg2). Inner sperm gutter (Fig.
298 HOUBRICK
5C,D, sg2) extending for two-thirds of lamina with that of any other species except Campa-
length, and entering duct leading to posterior nilesymbolicum Iredale, 1917, with which it is
seminal receptacle (Fig. 5D. sr); outer gutter convergent. The adult shell is normally 90-
(Fig. 5C,D, sgl) extending for more than two- 100 mm long, but Brandt (1974:196) has re-
thirds of length of medial lamina, entering into corded a very large specimen reaching 130
mm
spermatophore bursa (Fig. 5D. sb) in poste- in length. Telescopium telescopium is
rior third of lamina. Lateral lamina (Fig. 5C,D, one of the few gastropods with an aperture
II) bifurcate at free edge, with one lamina ad- tangential (perpendicular) to the shell axis.
jacent to oviductal groove and other lamina The anterior canal is nearly centrally located
compnsing broad, twisted parallel ridges (Fig. and weakly reflected dorsally (Fig. 1D,G,H).
5D, prd) with which tnfurcate edges of medial Sculptural elementsoccuronyoungerindivid-
lamina interdigitate. Glandular parts of bases uals (Fig. 1H-J), but are usually eroded in
of both laminae formed of paired row of nu- older shells (Fig. 1A-C). The columellar plait
merous thick, transverse ridges, bordering is strong at the aperture but becomes weaker
deep oviductal groove (Fig. 5C,D, ovg). Albu- internally (Fig. IL).
men gland (Fig. 5D, ag) in posterior portion of Telescopium mauritsi Butot, 1954, de-
oviduct. Capsule gland (Fig. 5D, eg) in thick- scribed from the Sunda Straits, Indonesia, as
ened base of anterior third of oviductal a new Recent species with smoother sculp-
groove. Male palliai oviduct unknown. Eus- ture, was latershown by Brandt (1974:196) to
permatozoa classified in structural group 2 be merely a gerontic, fully adult form of Tele-
(Healy, 1983:65,73). Paraspermatozoa with scopium telescopium, with its spiral sculpture
head region and tail tuft; assigned to struc- partly eroded, and covered with something
tural group 1 (Healy, 1986:187). that Brandt (1974:196) called "a secondary
Nervous System: Central nervous system layer of unknown substance." Budiman
(Fig. 3C) epiathroid. Cerebral ganglia (leg, (1988:240) also demonstrated that the two
rcg) with short commissure and with pleural taxa are indeed synonymous and joined by a
ganglia (rpl, Ipl) closelyjoined. Short connec- completeseriesofintermediateforms. Hefur-
tives (cpc) between cerebral and pedal gan- thershowedthatthe secondarycoating ofthe
glia: pedal-pleural connectives thin, adjacent smooth form is not part of tfie shell, but a
to pedal-cerebral connectives. Pedal ganglia deposit of an organo-metallic complex (Fe,
(rpg) each with three nerves and with stato- Mn), which is a common feature of epifaunal
cyst (st). Zygoneury (z) between subesoph- mollusks in this habitat.
ageal (sbg) and right pleural ganglia (rpl).
Very long connective (sec) between right Anatomy: The ventral and lateral grooves
pleural and supraesophageal ganglia (spg). (Fig. 3A,B, vg, llg) ofthe foot are unusual and
Dialyneury (d) between supraesophageal not seen in other potamidids. The slit-like
nerve and left palliai nerve (pn). Labial nerves opening to the anterior mucous gland is un-
very long, matching snout length. Long vis- usual inextendingfromtheedgeofthepropo-
ceral loop extending backtovisceral ganglion dium along both sides of the sole, for half its
at posterior end of mantle floor. distance (Figs. 2D, 3B, amg,). Both sexes
have a ciliated groove (Fig. eg) leading
Remarks from the exhalant siphon down the right side
ofthe foot tothe edge ofthe sole, whereas in
It is remarkablethat no contemporary stud- other potamidids and cerithioideans, the
ies have been made on the anatomy and life groove is seen only in females. Budiman
history of this large, common prosobranch. (1988:244) suggested that males use this
Aside from a few notes by Prashad (1925) on groove to transport and introduce sperm into
the mantlecavityand ctenidium, theonlypub- the female aperture. However, if spermato-
lished anatomical account of substance is an phores are present, as they are in all other
earlypaperby Berkeley& Hoffman (1834) de- known cerithioideans, this function is difficult
scribing the gross anatomy, but with several to visualize. The groove in males might
major errors. The nervous system was well merely remove mucus and debris from the
described and figured by Bouvier (1887:145- mantle cavity, transporting it in a mucous
146, pi. 8, fig. 32). ,string to the foot margin. The ovipositor (Fig.
Shell: The shell of Telescopium telescopium ovp) is near the edge of the foot and, in
is one of the most distinctive of all living section, is seen to comprise a glandular pad
prosobranchs, and Is not likelyto beconfused (Fig. 2A, ovp) thatdoes notmarktheentrance