Littorinidae LITTORINIDAE

Periwinkles

Diagnostic characters: Shell ovate-conical, usually strong and without

an umbilicus. Outer surface smoothish orwith spiral or nodular sculpture. Perios-tracum absent. Aperture rounded, por-celaneous, without a siphonal canal.Columella smooth or with a tooth-like swel-ling. Operculum thin and corneous, withrelatively few spiral coils and eitherovate with a lateral nucleus or roundedwith a subcentral nucleus. Head with ashort snout and conical tentacles bearingeyes on small swellings at their outerbases. Foot rather strong, the 2 sides ofwhich can move independently.Habitat, biology, and fisheries: Widelydistributed littoral animals, occurring intropical, temperate to cold climates, in theintertidal zone and the splash area wellabove high tide levels. Species living highup the shore can survive desiccation, andhave reduced gills and a vascularized mantle cavity acting as a primitive lung. Very common on rockyshores, or in tidal marshes and mangroves. Herbivores, feeding on algae which are grazed with a powerfulradula. Sexes separate, fertilization internal. Eggs generally laid in small corneous capsules and hatchingas free-swimming planktonic larvae, or brooded in the mantle cavity of the female. Littorinidae are easilycollected on the shore by coastal inhabitants, for subsistence or for local shellcraft.

Similar families occurring in the areaPlanaxidae: shape of shell very similar toLittorinidae, but readily distinguished by theshort, but distinct, anterior siphonal canalof the aperture.Trochidae: shell nacreous inside; opercu-lum rounded, with many coils and a subcen-tral nucleus.

Key to species of interest to fisheries occurring in the area1a. Operculum ovate, with a few spiral coils and a lateral nucleus (Fig. 1a); columella

completely smooth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 21b. Operculum rounded, with a moderate number of spiral coils and a central nucleus (Fig.

1b); columella with a more or less developed tooth-like swelling . . . . . . . . . . . . . . . . . → 3

ventral viewpaucispiraloperculum

ventral view

siphonalcanal

Planaxidaeventral view

interiornacreous

multispiraloperculum

Trochidae

a) Littoraria b) Tectarius

Fig. 1 operculum (exterior)

Littorinidae 431

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2a. Outer surface with 2 spiral rows of nodules; blue-grey in colour, with whitish nodulesand brown columella (Fig. 2) . . . . . . . . . . . . . . . . . . . . . . . . Nodilittorina pyramidalis

2b. Outer surface without nodulose sculpture; pale brown in colour, with dense pattern ofoblique, irregular dark stripes (Fig. 3) . . . . . . . . . . . . . . . . . . . . . . . . Littoraria scabra

3a. Shell relatively large (up to 6.5 cm in length); shoulder of whorls prominent, with a rowof keeled spines (Fig. 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tectarius pagodus

3b. Shell relatively small (up to 4 cm in length); shoulder not prominent, without a row ofcarinate spines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 4

4a. Suture deep; outer colour plain dull grey or greenish grey (Fig. 5) . . . . . . . Tectarius grandinatus4b. Suture shallow; outer colour cream to pinkish orange, with a dark spiral band under the

suture (Fig. 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tectarius coronatus

List of species of interest to fisheries occurring in the areaThe symbol� is given when species accounts are included.

� Littoraria scabra (Linnaeus, 1758)

� Nodilittorina pyramidalis (Quoy and Gaimard, 1833)

� Tectarius coronatus Valenciennes, 1832� Tectarius grandinatus (Gmelin, 1791)� Tectarius pagodus (Linnaeus, 1758)

ReferencesBandel,K. and D. Kadolsky. 1982. Western Atlantic species of Nodilittorina (Gastropoda: Prosobranchia): Comparative

morphology and its functional, ecological, phylogenetic and taxonomic implications. Veliger, 25(1):1-42.Reid, D.G. 1986. The littorinid molluscs of mangrove forests in the Indo-Pacific region. The genus Littoraria. London,

British Museum (Natural History), 228 p.Rosewater, J. 1970. The family Littorinidae in the Indo-Pacific. Part I. The subfamily Littorininae. Indo-Pac. Moll.,

2(11):417-506.Rosewater, J. 1972. The family Littorinidae in the Indo-Pacific. Part II. The subfamilies Tectariinae and Echininae.

Indo-Pac. Moll., 2(12):507-528.

whitishnodules

Fig. 2 Nodilittorina pyramidalis(ventral view)

Fig. 3 Littoraria scabra(ventral view)

keeledshoulders

Fig. 4 Tectarius pagodus(ventral view)

deep sutures

Fig. 5 Tectarius grandinatus(ventral view)

shallow sutures

Fig. 6 Tectarius coronatus(ventral view)

432 Gastropods

Littoraria scabra (Linnaeus, 1758)

Frequent synonyms / misidentifications: Littorina scabra (Linnaeus, 1758); Littorinopsis scabra (Lin-naeus, 1758) / Littorina angulifera Lamarck, 1822.FAO names: En - Rough periwinkle; Fr - Littorine rugueuse.

Diagnostic characters: Shell thin but solid, with a tall, conical spire and low sculpture. Spire whorlsconvex, with a narrowly channeled, incised suture, numerous, fine, low and flattened spiral cords anda raised, rounded cord determining a well-marked angle at periphery. Outer lip of aperture thin andsmooth. Columella smooth, straightish anteriorly and meeting the basal end of shell at an acute angle.Operculum ovate, with a few spiral coils and lateral nucleus. Colour: outside of shell whitish to palebrown, with dense pattern of dark brown and black dashes mostly on spiral cords, generally more orless aligned into oblique axial stripes. Peripheral cord usually with conspicuous white gaps betweenthe dashes. Aperture pale yellow to whitish, with the outer dark pattern showing through. Columellawhite, sometimes stained brown or purple.Size: Maximum shell length 4.4 cm, commonly to 3 cm.Habitat, biology, and fisheries: Abundant on trees and roots, at the seaward edge of mangrove areas,or sometimes on driftwood on sandy shores where mangroves are absent. Rare on sheltered rocks.Collected locally for food, notably in Viet Nam, the Gulf of Thailand and Indonesia.Distribution: Widespread inthe Indo-West Pacific, fromEast Africa, including Mada-gascar and the Red Sea, toeastern Polynesia; north tosouthern Japan and Hawaii,and south to souther nQueensland and New Cale-donia.

ventral view

(after Dance, 1993)

dorsal view

Littorinidae 433

Tectarius grandinatus (Gmelin, 1791)

Frequent synonyms / misidentifications: Tectarius bullatus (Martyn, 1784) (Invalid name); T. coronarius(Lamarck, 1816) / None.FAO names: En - Hailstorm prickly-winkle; Fr - Littorine grêlée.

Diagnostic characters: Shell thick, with high conical shape and strong sculpture. Spire whorls convex,with deeply channeled suture, 4 spiral rows of rounded spines and a few, narrow spiral threads betweenthem. Spines generally not regularly aligned axially. Base of body whorl somewhat flattened, with nodulosespiral cords. Outer lip of the rounded aperture strongly thickened and grooved inside, tapering to athinner, crenulated outer edge. Inner lip with a thin glaze posteriorly and a tooth-like swelling anteriorly.Operculum rounded, with a moderate number of coils and a central, darker nucleus. Colour: outsideof shell generally yellowish white, often more or less coated by a thin, easily pealed off, greyish brownperiostracum. Aperture whitish, stained with brown on the posterior glaze of inner lip.Size: Maximum shell length 4 cm, commonly to 3 cm.Habitat, biology, and fisheries: On coral reef flats, near high tide levels, on jagged pieces of raised reef.Collected in Polynesia for food and to make decorative items.Distribution: Restr icted tothe tropical Southwest Pa-cific, from Tonga and Cook is-lands to French Polynesia.

ventral view dorsal view(after Salvat and Rives, 1975)

434 Gastropods

Nodilittorina pyramidalis (Quoy and Gaimard, 1833)

Frequent synonyms / misidentifications: Littorina monilifera Eydoux and Souleyet, 1852; L. pyramidalis Quoy andGaimard, 1833; Trochus nodulosus Gmelin, 1791 (not of Solander, 1766); Turbo trochiformis Dillwyn, 1817 (not ofBrocchi, 1814) / None.

En - Pyramidal prickly-winkle; Fr - Littorine pyramidale.Maximum shell length 2.5 cm, commonly to 2 cm. On shore rocks. Upper intertidal zone and splasharea of the supralittoral zone. Locally collected for food and for shell trade, especially in Viet Namand the Gulf of Thailand. Indo-West Pacific, from the west coast of India to eastern Polynesia; northto Japan and south to southern New South Wales and Norfolk Island; also occurring in Pitcairn andEaster islands (subspecies pascua).

Tectarius coronatus Valenciennes, 1832

Frequent synonyms / misidentifications: ? Tectarius rugosus (Wood, 1828) / Tectarius papillosus (Lamarck, 1822) (=Tectarius tectumperspicum (Linnaeus, 1758).

En - Coronate prickly-winkle; Fr - Littorine couronnée.Maximum shell length 4 cm, commonly to 3 cm. On shore rocks and limestone cliffs. High in theintertidal zone, well above high levels of neap tide. Sometimes used as food, but mainly collectedfor its decorative shell. Restricted to the tropical West Pacific, from the Philippines to centralIndonesia.

ventral view

(after Kira, 1962)

ventral view dorsal view

(after Dance, 1993)

Littorinidae 435

Tectarius pagodus (Linnaeus, 1758)

Frequent synonyms / misidentifications: Tectarius bicolor (Lamarck, 1822) / None.

En - Pagoda prickly-winkle; Fr - Littorine pagode.Maximum shell length 6.5 cm, commonly to 5 cm. Rocky shores and limestone cliffs. Upper intertidaland supralittoral zones. Locally collected for food and shell trade. Easternmost part of the IndianOcean and the tropical West Pacific, from the Andaman Sea and Cocos (Keeling) Islands toMelanesia; north to the Philippines and south to southern Papua New Guinea..

ventral view

(after Dance, 1974)

436 Gastropods

Cerithiidae CERITHIIDAE

Ceriths

Diagnostic characters: Shell elongate,thick and solid, sharply conical with a

high, many-whorled spire and small aper-ture. Sculpture variable, usually spiral ornodulose, and with axial ribs or varices. Um-bilicus generally absent. Periostracum obso-lete. Aperture with a distinct, anteriorsiphonal canal which may be drawn out, up-turned and often laterally twisted. Outer lipsomewhat expanded, usually notched pos-teriorly. Inner lip smooth or twisted. Opercu-lum ovate, corneous, with a few spiral coilsand an eccentric nucleus. Head with a largesnout and long, cylindrical tentacles bearingeyes on swellings of their outer bases. Footbroad and short, angular anteriorly. Fleshysiphon weakly developed.Habitat, biology, and fisheries: Mainly tropi-cal to warm temperate, shallow water animalsliving on sandy to muddy bottoms of marineand estuarine environments, though smallspecies may abound under rocks or on marinevegetation. Gregarious herbivores, grazing onsmall algae, bacteria and organic debris. Spe-cies are often specialized to different sizes offood particles, and may be locally extremelyabundant, where the habitat is favourable.Sexes separate, fertilization internal; sperm transferred during mating in spermatophores which disinte-grate at the entrance to the mantle cavity of the female. Eggs released on substrate in gelatinous masses,hatching as planktonic larvae or directly as crawling juveniles, depending on the species. As ceriths areoften abundant and easily accessible in coastal areas, they are commonlycollected locally, both for food and for shellcraft. Species living in mangrovesfrequently appear in the local markets mixed with Potamididae.

Similar families occurring in the areaPotamididae: shell very similar to Cerithiidae, but recognizable by therounded operculum with many spiral coils.

Key to species of interest to fisheries occurring in the area1a. Inner lip with a median oblique

fold extending internally alongthe entire axis of shell (Fig. 1) . . . . . → 2

1b. Inner lip without a medianoblique fold . . . . . . . . . . . . . . . → 5

2a. Sculpture mainly spiral (Fig.2). . . . . . . . . . . . Rhinoclavis sinensis

2b. Sculpture mainly axial . . . . . . . . . → 3

multispiral operculum

Potamididae

siphonalcanal

ventral view

paucispiraloperculum

high,conicalspire

innerlip

outerlip

obliquemedian

fold

Fig. 1 detail of aperture Fig. 2 Rhinoclavis sinensis(ventral view)

Cerithiidae 437

3a. Sculpture prominent, with 3 rows of rounded spines on each whorl (Fig. 3) . . . Rhinoclavis aspera3b. Sculpture relatively low, without spines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 4

4a. Shell shape slender (length-width ratio about 4:1), with flat-sided whorls; outer colouroften with spiral bands or blotches of tan to brown, more developed in the lower half ofwhorls (Fig. 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rhinoclavis fasciata

4b. Shell shape stocky (length-width ratio about 3:1), with inflated whorls;outer colour generallywhite to yellowish-brown, with pale banding under the suture (Fig. 5) . . . . . . .Rhinoclavis vertagus

5a. Shell medium-sized to large (up to 8 cm in length, or more); anterior end of outer lipexpanded over the siphonal canal in mature specimens . . . . . . . . . . . . . . . . . . . . . → 6

5b. Shell small (not exceeding 5 cm in length); anterior end of outer lip not expanded overthe siphonal canal in mature specimens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 8

6a. Whorls angulate in the middle, with a row of prominent nodules that do not disappeartowards body whorl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 7

6b. Whorls not angulate in the middle, with a row of spines under the suture that disappeartowards body whorl (Fig. 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . Pseudovertagus aluco

7a. Shell large sized (up to 15 cm in length); median tubercles very strong; outer lip flaring(Fig. 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cerithium nodulosum

7b. Shell medium sized (up to 8 cm in length); median nodules moderately strong; outer lipnot flaring (Fig. 8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cerithium echinatum

8a. Shell relatively small (up to 3 cm in length); outer colour pale cream with black blotchingon granules (Fig. 9) . . . . . . . . . . . . . . . . . . . . . . . . . .Clypeomorus batillariaeformis

8b. Shell relatively large (up to 5 cm in length); outer colour purple brown to black (Fig. 10). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Cerithium coralium

3 rowsof spines

Fig. 3 Rhinoclavis aspera(ventral view)

flat-sidedwhorls

Fig. 4 Rhinoclavis fasciata(ventral view)

convexwhorls

Fig. 5 Rhinoclavisvertagus (ventral view)

expandedend of

outer lip

Fig. 6 Pseudovertagusaluco (ventral view)

flaringouter lip

Fig. 7 Cerithiumnodulosum (ventral view)

Fig. 8 Cerithium echinatum(ventral view)

(ventral view)

Fig. 9 Clypeomorusbatillariaeformis

Fig. 10 Cerithiumcoralium (ventral view)

438 Gastropods

List of species of interest to fisheries occurring in the areaThe symbol� is given when species accounts are included.

� Cerithium coralium Kiener, 1841� Cerithium echinatum Lamarck, 1822� Cerithium nodulosum Bruguière, 1792

� Clypeomorus batillariaeformis Habe and Kosuge, 1966

� Pseudovertagus aluco (Linnaeus, 1758)

� Rhinoclavis aspera (Linnaeus, 1758)� Rhinoclavis fasciata (Bruguière, 1792)� Rhinoclavis sinensis (Gmelin, 1791)� Rhinoclavis vertagus (Linnaeus, 1758)

ReferencesHoubrick, R.S. 1978. The family Cerithiidae in the Indo-Pacific. Part 1: The genera Rhinoclavis, Pseudovertagus and

Clavocerithium. Monogr. mar. Moll., 1:1-130.Houbrick, R.S. 1985. Genus Clypeomorus Jousseaume (Cerithiidae: Prosobranchia). Smithson. Contr. Zool.,

(403):131 p.Houbrick, R.S. 1992. Monograph of the genus Cerithium Bruguière in the Indo-Pacific (Cerithiidae: Prosobranchia).

Smithson. Contr. Zool., (510):210 p.

Cerithiidae 439

Cerithium coralium Kiener, 1841

Frequent synonyms / misidentifications: Cerithium granosum Kiener, 1841; Clypeomorus coralium(Kiener, 1841) / Cerithium ruppelli Philippi, 1848.FAO names: En - Coral cerith; Fr - Cérithe corail.Diagnostic characters: Shell moderatelysmall and elongate, length almost 3 times aslong as width. Spire whorls straight sided, withdeeply incised sutures and randomly distributed,low axial varices. Sculpture of the spire com-posed of granulose spiral cords (3 in numberon later whorls) and many, fine spiral threads,crossed by axial ridges. Body whorl wide,weakly constricted at the base, with 5 or 6 beadedspiral cords and numerous fine grooves, but lack-ing axial ribs. A rather strong axial varix presenton dorsal side of body whorl.Outer lip of aperturethickened and somewhat protruding laterally,weakly crenulate on margin, with elongate den-ticles inside. Columella moderately concave,narrowly and thickly calloused, with a tooth-likeridge at posterior end but without a medianoblique fold. Anterior siphonal canal short,broad and only slightly recurved. Colour:outer coloration of shell variable, purple brownto black or dirty grey, sometimes banded withbrown or whitish, and with dark granules. Aper-ture white, sometimes brownish.Size: Maximum shell length 5 cm, commonly to3 cm.Habitat, biology, and fisheries: On midtidal mud flats of estuarine and mangrove areas, commonlyassociated with various Potamididae such as Cerithidea cingulata (Gmelin). May occur in very densepopulations. Often collected for food together with Potamididae, and sold with them in the local markets.An important species off the Coromandel coast of India.Distribution: Indo-WestPacific, from the west coast ofIndia and Sri Lanka to easternMelanesia; north to Japan andsouth to New South Wales andNew Caledonia.

ventral view

(after Houbrick, 1992)

dorsal view

440 Gastropods

Cerithium echinatum Lamarck, 1822

Frequent synonyms / misidentifications: Cerithium mutatum Sowerby, 1834; C. rubus Deshayes, 1843 /None.FAO names: En - Spinose cerith; Fr - Cérithe épineux.Diagnostic characters: Shell medium sized, stout andstrongly sculptured, length only a little more than twiceas long as the width. Spire whorls convex, with a medianspiral cord bearing prominent, spinose nodules, 3 or 4minor, sometimes spinose, nodulose spiral cords andincised spiral grooves between them. Nodes and spinesoften drawn out axially, forming low axial ridges. Apertureovate, with a narrowly channeled posterior end. Outer lipthickened, somewhat protruding laterally, crenulate andspinose at margin, with its anterior end partly expandedover the siphonal canal. Columella slightly concave, witha thick callus, a well-marked lip and a strong ridge nearposterior end, but without a median oblique fold. Ante-rior siphonal canal rather short, tubular and recurveddorsally and to the left. Colour: outside of shell cream,with variable purplish brown spots. Aperture por-celaneous white.Size: Maximum shell length 8 cm, commonly to 6.5 cm.Habitat, biology, and fisheries: On rocky and coral reefareas. Intertidal and shallow sublittoral zones. Often verycommon. Collected by coastal populations in the tropicalWest Pacific for food and shell trade.Distribution: Widespread in the Indo-West Pacific, fromEast Africa, including the Red Sea and Madagascar, toeastern Polynesia and Easter Island; north to Japan, Mid-way and Hawaii, and south to southern Queensland andNew Caledonia.

ventral view

(after Short and Potter, 1987)

Cerithiidae 441

Cerithium nodulosum Bruguière, 1792

Frequent synonyms / misidentifications: Cerithiumm erythraeonense Lamarck, 1822 / None.FAO names: En - Giant knobbed cerith; Fr - Cérithe noduleux.Diagnostic characters: Shell large, solid, elon-gate and heavily sculptured. Spi re whorlsstrongly angulate at periphery, each bearing asingle row of conspicuous tubercles and anumber of weakly nodulose spiral cords. Bodywhorl very large, with strongly prominent mediantubercles on its dorsal side and a very large wartyvarix on left side, above the siphonal canal. Basestrongly excavated, with about 5 coarse nodulosespiral ribs and deep grooves between. Aperturelarge, with a posterior canal determined by a strongspiral ridge near posterior end of inner lip. Outer lipthick, flaring, strongly crenulate and spirallychanneled inside, with an anterior claw-like exten-sion crossing over the siphonal canal. Co-lumella concave, narrowly and thickly calloused,but without a median oblique spiral fold. Anteriorsiphonal canal rather short, constricted and re-curved dorsally and laterally. Colour: outside ofshell often encrusted with calcareous growths, dirtywhite or cream with irregular greyish brown axialspots, streaks and blotches. Aperture porcelane-ous white, sometimes with a few dark blotchesdeeply inside.Size: Maximum shell length 15 cm, commonly to12 cm.Habitat, biology, and fisheries: In sand and rub-ble, on intertidal reef flats, usually near the outeredge of reefs. Commonly collected in the Indo-WestPacific, for food and shell trade.Distribution: Widespread inthe Indo-West Pacific, fromEast Africa to western Polyne-sia; north to southern Japanand south to southernQueensland and New Caledo-nia; the form occurring fromthe Red Sea to the Gulf ofOman is usually distinguishedunder the name Cerithiumerythraeonense.

ventral view

(after Short and Potter, 1987)

442 Gastropods

Clypeomorus batillariaeformis Habe and Kosuge, 1966

Frequent synonyms / misidentifications: Cerithium moniliferum Kiener, 1841 (not of Deshayes, 1833) /Cerithium humilis Dunker, 1861; C. morus Lamarck, 1822; C. tuberculatum (Linnaeus, 1758); Clypeo-morus bifasciata (Sowerby, 1855).FAO names: En - Necklace cerith; Fr - Cérithe collier.Diagnostic characters: Shell small, squat,length always less than 3 times as long as width.Surface of early whorls usually strongly eroded.Spire whorls slightly inflated, with moderatelyincised sutures, 3 equally spaced spiral cordsthat are beaded with smooth, rounded to some-what elongate granules, and finer interstitialspiral threads. Anterior cord frequently smallerand with less distinct granules than the 2 othercords. Body whorl with 6 to 8 main spiral beadedcords, and a strong, slightly oblique, axial varixon left part of dorsal side. Beaded sculpture ofshell usually not aligned axially. Outer lip ofaperture rounded, moderately thickened, smoothto weakly crenulate on margin and finely lirateinside. Columella concave, poorly calloused, witha thick ridge at posterior end but without a me-dian oblique fold. Anterior siphonal canal veryshort and narrow, deeply incised directed left-ward at about 45° to shell axis. Colour: outsideof shell with variable coloration, often pale greyor cream with dark brown or black granuleswhich may be drawn out into transverse lines.Aperture whitish on margins of mature speci-mens, spirally banded with black inside.Size: Maximum shell length 3 cm, commonly to 2.5 cm.Habitat, biology, and fisheries: On sandy bottoms of reef flats and estuaries. Intertidal, often in extremelydense populations. Collected in fairly large quantities in the northern Philippines.Distribution: Widespread inthe Indo-West Pacific, fromEast Africa, including the Sey-chelles and Western India, toeastern Polynesia, but not inthe northwestern part of theIndian Ocean, the Red Sea orthe Persian Gulf; nor th tosouthern Japan and south tosouthern Queensland andNew Caledonia.

ventral view(after Wilson, 1993)

dorsal view

Cerithiidae 443

Rhinoclavis fasciata (Bruguière, 1792)

Frequent synonyms / misidentifications: Cerithium bandatum Perry, 1811; C. fasciatum Bruguière,1792; C. procerum Kiener, 1841; Clava fasciata (Bruguière, 1792) / None.FAO names: En - Banded vertagus; Fr - Cérithe fascié.Diagnostic characters: Shell medium sized, solid, fusi-form and elongate, with a slightly stepped spire andslender shape. Shell length about 4 times as long aswidth. Spire whorls flat sided, with incised sutures.Sculpture relatively low, variable, with 2 to 4 well-marked spiral grooves per whorl and flattened, shortaxial ribs at suture, that are prominent on earlier whorlsand less distinct or lacking on later ones. Surface of earlywhorls often with a cancellate appearance. No axialvarices. Aperture obliquely ovate, almost fusiform, with anarrow sharp posterior end. Outer lip smooth, slightlythickened and broadly curved, almost straight posteriorly.Inner lip thickened, with a strong median oblique foldextending internally along the entire axis of shell.Anterior siphonal canal rather long and recurved dor-sally almost at a right angle to the coiling axis of shell.Colour: outside of shell glossy, very variable in colora-tion, mostly white with spiral bands or blotches of tanto brown that are more developed in the lower (anterior)half of whorls. Aperture porcelaneous white.Size: Maximum shell length 9.5 cm, commonly to 8 cm.Habitat, biology, and fisheries: Common in clean sandybottoms of coral reef areas. Subtidal, to a depth of 18 m.Most common to a depth of 10 m, sometimes in very densecolonies. Collected locally for food in the Indo-Pacific, butmainly used for its shell.Distribution: Widespread inthe Indo-West Pacific, fromEast Africa, including Mada-gascar, the Red Sea and thePersian Gulf, to eastern Poly-nesia; north to Japan, Midwayand Hawaii, and south toQueensland and New Caledo-nia.

ventral view

(after Habe, 1964)

444 Gastropods

Rhinoclavis vertagus (Linnaeus, 1758)

Frequent synonyms / misidentifications: Cerithium vertagus (Linnaeus, 1758); Clava vertagus (Lin-naeus, 1758); Vertagus communis Schumacher, 1817 / None.FAO names: En - Common vertagus; Fr - Cérithe vautre.Diagnostic characters: Shell medium sized, solid,fusiform, with a slightly stepped spire and stockyshape. Shell length about 3 times as long aswidth. Spire whorls somewhat inflated, smoothanteriorly and more swollen near the moderatelyincised suture. Sculpture relatively low, with finespiral grooves and strong short axial folds un-der suture, becoming obsolete anteriorly and onbody whorl. Surface of early whorls rugose. Lowaxial varices present on all earlier whorls of spire,weaker on later whorls and frequently absent onbody whorl. Aperture obliquely ovate, almost fusi-form, with a narrow sharp posterior end. Outer lipsmooth, rather thin and broadly curved, almoststraight posteriorly. Inner lip thickened, with astrong median oblique fold extending internallyalong the entire axis of shell. Anterior siphonalcanal rather long and recurved dorsally almost ata right angle to the coiling axis of shell. Colour:outside of shell generally bright white to yel-lowish brown, with pale banding under the su-ture. Aperture porcelaneous white.Size: Maximum shell length 7 cm, commonly to5 cm.Habitat, biology, and fisheries: Abundant onsandy substrates. Intertidal and shallow sublittoralzones to a depth of 13 m. Collected mainly for itsshell, though occasionally eaten, especially in thenorthern Philippines where it appears in the localmarkets.Distribution: Widespread inthe Indo-West Pacific, fromEast Africa, including Mada-gascar and Sri Lanka to Mela-nesia, but apparently not inthe nor thwes ter n IndianOcean, the Red Sea nor thePersian Gulf, north to south-ern Japan and south to south-ern Queensland and NewCaledonia.

ventral view

(after Habe, 1964)

oblique viewof aperture

medianfold

Cerithiidae 445

Pseudovertagus aluco (Linnaeus, 1758)

Frequent synonyms / misidentifications: Cerithium aluco (Linnaeus, 1758); Rhinoclavis aluco (Linnaeus, 1758);Vertagus aluco (Linnaeus, 1758); V. cumingii “A. Adams” of authors / None.

En - Aluco vertagus; Fr - Cérithe aluco.Maximum shell length 10 cm, commonly to 7.5 cm. Seagrass beds and coral rubble. Intertidal andshallow sublittoral zones. Locally collected for food and shell trade. Tropical West Pacific, fromIndonesia to western Polynesia; north to Japan and south to Queensland and New Caledonia.

Rhinoclavis aspera (Linnaeus, 1758)

Frequent synonyms / misidentifications: Cerithium asperum (Linnaeus, 1758); C. lineatum Lamarck, 1822; Clavaaspera (Linnaeus, 1758); Vertagus granulatus (Linnaeus, 1758) / None.

En - Rough vertagus; Fr - Cérithe rêche.Maximum shell length 6 cm, commonly to 5 cm. In sandy areas associated with coral reefs, fromshallow subtidal waters to a depth of about 30 m. One of the most common gastropods in somelagoons of the Indo-West Pacific. Like other ceriths, locally collected by coastal people, whereabundant. Widespread in the Indo-West Pacific, from East Africa, including Madagascar and theRed Sea, to eastern Polynesia; north to Japan, Wake and Hawaii, and south to Queensland andNew Caledonia.

ventral view

(after Short and Potter, 1987)

ventral view

(after Short and Potter, 1987)

446 Gastropods

Rhinoclavis sinensis (Gmelin, 1791)

Frequent synonyms / misidentifications: Cerithium chinensis (Chemnitz, 1882) (Invalid name); C. obeliscusBruguière, 1792; Clypeomorus obeliscus (Bruguière, 1792); Ochetoclava sinensis (Gmelin, 1791); Pseudovertagussinensis (Gmelin, 1791) / None.

En - Obelisk vertagus; Fr - Cérithe obélisque.Maximum shell length 7 cm, commonly to 5 cm. On reef flats and lagoons, in sandy, coral rubblebottoms. Intertidal and sublittoral, to a depth of 23 m. Common, and frequently heavily preyed uponby other gastropods such as ranellids, muricids and naticids, or by crabs. Collected for food and itsshell where abundant. An important species off the Coromandel coast of India. Widespread in theIndo-West Pacific, from East and South Africa, including Madagascar, the Red Sea and the PersianGulf, to eastern Polynesia; north to Japan, Midway and Hawaii, and south to central Queenslandand New Caledonia.

(after Short and Potter, 1987)

ventral view

Cerithiidae 447

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