CARDIIDAE posterior cardinal tooth D · anterior and posterior lateral teeth, typically present in...

CARDIIDAE

Cockles

Diagnostic characters: Shell equivalve, inflated,oval to subtrigonal or subquadrate, often with a

posterior ridge or angulation; sometimes very com-pressed anteroposteriorly, and heart-shaped whenviewed from the anterior side. Umbones prosogyrate toorthogyrate, prominent, approximate. External sculp-ture mostly radial, often more or less differing on poste-rior slope. Periostracum usually weak to inconspicuous,rarely well developed. Ligament external, a short andprominent arched band behind the umbones. Hingecharacteristic,with teeth curving outwards rather thanbeing set on a flat hinge plate; 2 cardinal teeth, andanterior and posterior lateral teeth, typically present ineach valve; cardinal teeth cruciform in arrangement,when valves interlock. Two subequal adductor musclescars.Pallial line without a sinus. Internal margins withcrenulations, generally corresponding with the outersculpture. Gills of eulamellibranchiate type, folded, withdorsoventrally slanting axis. Foot strong and long, sickle-shaped.Mantle widely open ventrally, smooth or papillate,sometimes with marginal eyes.Siphons naked, short andseparate, papillate on top.Habitat, biology, and fisheries: Shallow burrowers in sandy to muddybottoms, most common in littoral and shallow subtidal waters. The geniculatefoot can be used for jumping to escape predators. Sexes generally separate.Development with a free-swimming larval stage. In the tropical West Pacific,cockles are mainly collected for their shells, which are used as decorative itemsin local shellcraft. They are also eaten by coastal people and occasionallyappear in local markets.

Similar families occurring in the areaThe characteristic features of the hinge easily distinguish members of theCardiidae from other radially ribbed eulamellibranchiate bivalves such as theCarditidae.

Key to species of interest to fisheries occurring in the area1a. Shell strongly compressed anteroposteriorly; inflation about twice the length (Fig. 1)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Corculum cardissa1b. Shell not strongly compressed anteroposteriorly; inflation nearly equal to or smaller than

length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 2

2a. Shell thin and fragile; outer sculpture feeble, of low radial ribblets with fine tufts ofperiostracum arising from radial grooves on top (Fig. 2) . . . . . . . . . . . . . . Fulvia papyracea

2b. Shell relatively thick and solid; outer sculpture of strong radial ribs with different characters . . . . . → 3

3a. Posterior slope markedly set off from the rest of the shell by a strong radial angulation;posterior margin meeting ventral margin at an angle of 90° or less . . . . . . . . . . . . . . . . → 4

3b. Posterior slope not markedly set off from the rest of the shell; posterior margin meetingventral margin roundly or at an obtuse angle . . . . . . . . . . . . . . . . . . . . . . . . . . . → 6

posterior cardinal toothanterior

cardinal tooth

anteriorlateral tooth

pallial linemarginalcrenulations

posterior lateraltooth

ligament

interior of left valve


Carditidae

rightvalve

inflation

length

Fig. 1 Corculum cardissa (dorsal view) Fig. 2 Fulvia papyracea (exterior)

250 Bivalves

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4a. Umbonoventral angulation forming a prominent keel; interstices of radial ribs trans-versely grooved (Fig. 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fragum hemicardium

4b. Umbonoventral angulation not forming a prominent keel; interstices of radial ribs smooth . . . . . → 5

5a. Scales of radial ribs widely spaced and bright red (Fig. 4) . . . . . . . . . . . . . . Fragum unedo5b. Scales of radial ribs close set and whitish (Fig. 5) . . . . . . . . . . . . . . . . . . Fragum fragum

6a. Shell height about equal or smaller than length; cardinal teeth similar in size (Fig. 6a) . . . . . → 76b. Shell height greater than length; cardinal teeth distinctly unequal in size (Fig. 6b) . . . . . . . → 9

7a. Anterior and posterior sections of hinge almost the same size; outer surface with minutepustules, at least in the interstices of ribs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 8

7b. Anterior section of hinge shorter than posterior; outer surface devoid of minute pustules(Fig. 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Plagiocardium pseudolatum

8a. Shell subequilateral, about as long as high; at least 26 radial ribs, with a series of erectlamellate spines forming a prominent, continuous palisade near shell margin (Fig. 8). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vepricardium asiaticum

8b. Shell inequilateral, longer than high; from 22 to 24 radial ribs, with small granules or aseries of short spines, but not forming a prominent palisade near shell margin (Fig. 9). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vepricardium sinense

9a. Shell strongly inequilateral in outline, flared out posteroventrally; ribs of posteromedialarea triangular and asymmetrical in cross-section (Fig. 10) . . . . . . . Trachycardium angulatum

9b. Shell not much inequilateral in outline; ribs of posteromedial area rounded to quadratein cross-section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 10

grooved interstices

Fig. 3 Fragum hemicardium (exterior)

red scales

Fig. 4 Fragum unedo (exterior)

white scales

Fig. 5 Fragum fragum (exterior)

a) Vepricardium b) Trachycardium

Fig. 6 interior of left valve Fig. 7 Plagiocardium pseudolatum (exterior)

Fig. 8 Vepricardium asiaticum(exterior)

triangularribs

Fig. 9 Vepricardium sinense(exterior)

Fig. 10 Trachycardium angulatum(exterior)

Cardiidae 251

10a. At least 38 radial ribs; ribs of posteromedial area quadrate in cross-section; internalmargins deep purple (Fig. 11) . . . . . . . . . . . . . . . . . . . . . . . . . Trachycardium orbita

10b. At most 32 radial ribs; ribs of posteromedial area not quadrate in cross-section; internalmargins whitish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 11

11a. Radial ribs relatively low, those of posterior slope feeble and smoothish (Fig. 12). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trachycardium subrugosum

11b. Radial ribs relatively high, those of posterior slope well marked and spinose (Fig. 13). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trachycardium rugosum

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

� Corculum cardissa (Linnaeus, 1758)

� Fragum fragum (Linnaeus, 1758)� Fragum hemicardium (Linnaeus, 1758)� Fragum unedo (Linnaeus, 1758)

� Fulvia papyracea (Bruguière, 1789)

� Plagiocardium pseudolatum (Voskuil and Onverwagt, 1991)

� Trachycardium angulatum (Lamarck, 1819)� Trachycardium orbita (Sowerby, 1833)� Trachycardium rugosum (Lamarck, 1819)� Trachycardium subrugosum (Sowerby, 1840)

� Vepricardium asiaticum (Bruguière, 1789)� Vepricardium sinense (Sowerby, 1841)

ReferencesBartsch, P. 1947. The little hearts (Corculum) of the Pacific and Indian Oceans. Pac. Sci., 1:221-226.Keen, A.M. 1980. The pelecypod family Cardiidae: a taxonomic summary. Tulane Stud. Geol. Paleont., 16(1):1-40.Lambiotte, M. 1979. Note sur Cardium burnupi G.B. Sowerby, 1897. Inf. Soc. belg. Malac. 7(2):49-50.Voskuil, R.P.A. and W.J.H. Onverwagt. 1991a. Studies on Cardiidae. 3. The recent species of Maoricardium Marwick,

1944 (Mollusca, Bivalvia), with description of a new species. Basteria, 55:25-33.Voskuil, R.P.A. and W.J.H. Onverwagt. 1991b. Studies on Cardiidae. 4. The taxonomy of the genus Trachycardium (Part 1)

with description of three new species. (Mollusca: Bivalvia). Vita marina, 41(2):56-72.Wilson, B.R. and S.E. Stevenson. 1977. Cardiidae (Mollusca, Bivalvia) of Western Australia. West. Aust. Mus. spec.

Publ., (9):1-114.

Fig. 11 Trachycardium orbita(exterior)

Fig. 12 Trachycardium subrugosum(exterior)

Fig. 13 Trachycardium rugosum(exterior)

252 Bivalves

Fragum fragum (Linnaeus, 1758)

Frequent synonyms / misidentifications: Cardium imbricatum Born, 1778;Corculum fragum (Linnaeus,1758); Fragum flavum Röding, 1798 / None.FAO names: En - White strawberry cockle; Fr - Bucarde à collier.

Diagnostic characters: Shell solid, inequilateral, trapezoidal in outline, with rounded anterior andalmost straight, high posterior margins. Posterior slope markedly set off from the rest of the shell by asharp radial angulation. Anterodorsal margin longer than posterodorsal margin. Posterior and ventralmargins meeting at an angle distinctly less than 90°. About 32 low and flat radial ribs (27 to 37) at eachvalve, with close-set transverse scales that become coarser on the anterior part of shell. Interstices ofribs narrow and smooth. Hinge stout, strongly bent under the umbones. Cardinal teeth of right valveconnected dorsally. Posterior lateral teeth much closer to cardinals than anterior laterals. Internal marginscrenulated, the posterior one with sharp points.Colour: outside white, often with pale pink to fawn blotchestowards the umbones, scales on ribs light yellow. Interior white, usually with some pale orange to pinkradial flares in the umbonal cavity.Size: Maximum shell height 4 cm, commonly to 3 cm.Habitat, biology, and fisheries: In littoral and sublittoral sand to a depth of 20 m. Frequently occurring indense populations in shallow subtidal bottoms. Commonly collected in many areas, mainly for decorativepurposes.Distribution: Widespreadin the Indo-West Pacific,from East Africa, includingMadagascar and the RedSea to eastern Polynesia;north to southern Japan andsouth to Queensland.

interior of left valve exterior of right valve

Cardiidae 253

Fragum hemicardium (Linnaeus, 1758)

Frequent synonyms / misidentifications: Corculum hemicardium (Linnaeus, 1758); Lunulicardiahemicardia (Linnaeus, 1758); L. tumorifera (Lamarck, 1819) / None.FAO names: En - Pacific half cockle; Fr - Bucarde demi-coeur.

Diagnostic characters: Shell solid, inequilateral, trapezoidal in outline, with sharply rounded anteriorand feebly convex, high posterior margins. Posterior slope markedly set off from the rest of the shell bya sharp and prominent radial keel. Anterodorsal margin longer and more sloping than posterodorsalmargin. Posterior and ventral margins meeting at an acute angle. About 23 flattened radial ribs (18 to27) at each valve, those on medial part of the shell usually bearing a row of rounded nodules. Intersticesof ribs narrow and pitted or with transverse bars. Hinge stout, strongly bent and thickened under theumbones. Cardinal teeth of right valve connected dorsally. Posterior lateral teeth closer to cardinals thananterior laterals. Internal margins with wide crenulations. Colour: outside white, sometimes with a palepink or fawn hue under the thin, straw-coloured periostracum. Interior white.Size: Maximum shell height 5.5 cm, commonly to 4 cm.Habitat, biology, and fisheries: In littoral and shallow sublittoral sandy bottoms. Sometimes abundant inintertidal sand flats of sheltered bays. Of potential interest for a commercial exploitation in northwesternAustralia.Distribution: Widespreadin the Indo-West Pacific,f rom East Af r ica toPolynesia; nor th to thePhilippines and southernChina, and south toQueens land and NewCaledonia.


254 Bivalves

Fragum unedo (Linnaeus, 1758)

Frequent synonyms / misidentifications: Corculum unedo (Linnaeus, 1758) / None.FAO names: En - Pacific strawberry cockle; Fr - Bucarde fraise.

Diagnostic characters: Shell solid, inequilateral, subquadrate in outline, with rounded anterior andalmost straight posterior margins. Posterior slope set off from the rest of the shell by a rounded radialangulation. Anterodorsal and posterodorsal margins approximately equal in length. Posterior andventral margins meeting almost at right angle. About 27 broad, low and flat radial ribs (23 to 31) at eachvalve, with distantly spaced transverse scales that become coarser and more numerous on the anteriorpart of shell. Interstices of ribs narrow and smooth. Hinge stout, strongly bent under the umbones.Cardinal teeth of right valve connected dorsally. Posterior lateral teeth slightly closer to cardinals thananterior laterals. Internal margins crenulated, the posterior one with sharp points. Colour: outside of shellwhite or cream, with bright pink to dark red scales. Interior white.Size: Maximum shell height 6.5 cm, commonly to 4 cm.Habitat, biology, and fisheries: Shallow burrower of sandy bottoms, frequently occurring in densepopulations. Most common in clean sand in shallow water. Littoral and sublittoral to a depth of 50 m.Exploitation at subsistence level in many areas. Appears in local markets in the central Philippines. Theshell is commonly used in the shellcraft industry for decorative items. Of potential interest in WesternAustralia.Distribution: Central andeastern Indian Ocean towes ter n Pac i f ic , f romMauritius Island and SriLanka to eastern Melanesia,north to southern Japan andsouth to Queensland.


exterior of right valve

Cardiidae 255

Trachycardium rugosum (Lamark, 1819)

Frequent synonyms / misidentifications: Acrosterigma rugosa (Lamarck, 1819); Cardium flavum“Linnaeus, 1758" (Dubious name); ? C. pectiniforme Born, 1780; Vasticardium nigropunctatum Habe andKosuge, 1966 / Trachycardium dupuchense (Reeve, 1845); T. marerubrum Voskuil and Onverwagt, 1991.FAO names: En - Pacific yellow cockle; Fr - Bucarde rugueuse.

Diagnostic characters: Shell moderately thick, oblong-ovate and higher than long, slightly inequilateral withposterior part tending to be slightly expanded. About 30 prominent, rounded and rugose radial ribs (27 to32) at each valve. Interstices of ribs relatively deep and flat, with fine concentric striations.Radial ribs bearingtransverse scales on sides and top on the anterior half of shell, becoming smooth on top and finely crenate onsides behind the midline; ribs of posterior slope narrower and distinctly spinose. Periostracum thin andclosely appressed to the shell, slightly fibrous, mostly persisting on periphery and in rib interstices. Hinge rathershort and stout, arched. Cardinal teeth strongly unequal, anterior right and posterior left teeth reduced. Anteriorand posterior lateral teeth approximately equidistant from cardinals. Internal margins strongly crenulated.Colour: outside of shell whitish, periostracum straw colour to olive-brown, sometimes with a scatteringof black spots. Interior completely white, or more or less stained yellow.Size: Maximum shell height 6.5 cm, commonly to 5 cm.Habitat, biology, and fisheries: In coral sand and muddy-sand flats of sheltered areas, often forming largebeds. Intertidal and shallow sublittoral waters to depths of about 20 m. Artisanally collected for food inIndo-China and the Philippines. The shell is used in local shellcraft.Distribution: Widespread in the Indo-West Pacific, from East and Southeast Africa to eastern Indonesia;north to Japan and south to Queensland.Remarks: There has beenmuch confusion concerningthis species, which is oftenmisidenti f ied with othermembers of the genus.Al though recently andfrequently used, the Linnaeanname Cardium flavum isindeterminable and thereforeconsidered invalid. Due to apending revision of the group,C. rugosum Lamarck is usedhere as the first definite namecorrect ly appl ied to thisspecies.


256 Bivalves

Corculum cardissa (Linnaeus, 1758)

Frequent synonyms / misidentifications: Corculum aselae Bartsch, 1947; C. dionaeum (Sowerby, 1829); C. kiraiShikama, 1964; C. laevigatum Bartsch, 1947; C. obesum Bartsch, 1947; C. unimaculatum (Broderip and Sowerby, 1833)/ None.

En - True heart cockle; Fr - Bucarde coeur.Maximum shell height 8 cm, commonly to 5 cm. In sandy bottoms, with the flattish posterior surface ofshell lying horizontally just beneath the surface. Sometimes in dense colonies and often associated tocoral reefs. Littoral and shallow sublittoral waters to a depth of 20 m.Artisanally collected in some areas,commonly in Thailand. Mainly used as an ornamental shell. Widespread in the Indo-West Pacific, fromMauritius Island, the Red Sea and the Persian Gulf, but probably not on the East African coast, to easternPolynesia; north to Japan and south to northern Queensland and New Caledonia. The small formoccurring in the tropical western Pacific islands is often considered a distinct species under the nameCorculum dionaeum (Sowerby, 1829).

Fulvia papyracea (Bruguière, 1789)

Frequent synonyms / misidentifications:Cardium natalense Krauss, 1848;C.papyraceum Chemnitz, 1782 (Invalid name);Laevicardium papyraceum (Bruguière, 1789) / Fulvia aperta (Bruguière, 1789).

En - Paper cockle; Fr - Bucarde papier.Maximum shell length 6 cm, commonly to 5 cm. In muddy of sheltered bays and estuaries, from lowtide level to shallow sublittoral waters. Collected for food and marketed in Thailand and Viet Nam.Apparently widely distributed in the Indo-West Pacific, the distribution of this species is imperfectlyknown because of frequent confusion with other species of the genus. Reported from East Africa,including South Africa and the Red Sea, to southern Japan, the Philippines, and eastern Indonesia.

anterior view of entire shell dorsal view of entire shell

interior of leftvalve

exterior of rightvalve


exterior of right valve(after Kilburn and Rippey, 1982)

?

?

Cardiidae 257

Plagiocardium pseudolatum (Voskuil and Onverwagt, 1991)

Frequent synonyms / misidentifications: Cardium latum of Authors (not of Born, 1780); Maoricardium pseudolatumVoskuil and Onverwagt, 1991 / Plagiocardium setosum (Redfield, 1846).

En - Broad cockle; Fr - Bucarde large.Maximum shell length 7.5 cm, commonly to 4.5 cm. In littoral and shallow sublittoral sandy bottoms.Collected for food and used in the local shellcraft industry in the central Philippines. Central andeastern Indian Ocean to tropical western Pacific, from India and Sri Lanka, including Réunion andMauritius islands and the Persian Gulf, to Solomon Islands; north to southern Japan and south tonorthern Queensland.

Trachycardium angulatum (Lamarck, 1819)

Frequent synonyms / misidentifications: Acrosterigma angulata (Lamarck, 1819); Trachycardium alternatum(Sowerby, 1840); Vasticardium alternatum (Sowerby, 1840) / None.

En - Angulate cockle; Fr - Bucarde anguleuse.Maximum shell height 9.5 cm, commonly to 7 cm. In sandy bottoms. Littoral and shallow sublittoralwaters to a depth of 20 m. Collected for food in the Philippines; the shell is used as raw material inlocal shellcraft. Western Indian Ocean, in East and Southeast Africa, Madagascar, the Seychellesand Mauritius Island, and western tropical Pacific, from Indonesia to Solomon Islands; north tosouthern Japan and south to Queensland and New Caledonia.


(after Voskuil and Onverwagt, 1991)



258 Bivalves

Trachycardium orbita (Sowerby, 1833)

Frequent synonyms / misidentifications: Cardium orbita Sowerby, 1833; C. philippinense “Deshayes” Shirley, 1912;Trachycardium hawaiensis Dall, Bartsch, and Rehder, 1938; Vasticardium orbita (Sowerby, 1833) / None.

En - Orbit cockle; Fr - Bucarde à ornières.Maximum shell height 9.3 cm, commonly to 7 cm. In sandy bottoms, from low tide levels to shallowsublittoral depths. Collected for food in Polynesia. Widespread in tropical West Pacific islands, fromthe Philippines to Hawaii and eastern Polynesia.

Trachycardium subrugosum (Sowerby, 1840)

Frequent synonyms / misidentifications: Acrosterigma subrugosa (Sowerby, 1840) / Trachycardium rugosum(Lamarck, 1819).

En - Wrinkled cockle; Fr - Bucarde ridée.Maximum shell height 6 cm, commonly to 5 cm. In sandy bottoms. Intertidal and sublittoral watersto a depth of 20 m. Locally collected and marketed. Eastern Indian Ocean to the tropical westernPacific, from Nicobar Islands to Melanesia; north to southern Japan and south to New Caledonia.





Cardiidae 259

Vepricardium asiaticum (Bruguière, 1789)

Frequent synonyms / misidentifications: Cardium asiaticum Bruguière, 1789; Trachycardium asiaticum (Bruguière,1789); ? Vepricardium coronatum (Spengler, 1799); Vepricardium fimbriatum (Wood, 1815) / Vepricardium burnupi(Sowerby, 1897).

En - Asiatic cockle; Fr - Bucarde asiatique.Maximum shell length 5 cm, commonly to 4 cm. In muddy-sand bottoms, from lower parts of theintertidal zone to depths of about 100 m. Locally abundant. Collected for food in the Gulf of Thailand.Widespread in the Indo-West Pacific, from East Africa, including Madagascar and the Persian Gulf,to the Philippines; north to Taiwan Province of China and south to Indonesia.

Vepricardium sinense (Sowerby, 1841)

Frequent synonyms / misidentifications: Cardium sinense (Sowerby, 1841) / None.

En - Chinese cockle; Fr - Bucarde chinoise.Maximum shell length 4.5 cm, commonly to 3.5 cm. In muddy-sand bottoms, from shallow subtidalwater to a depth of about 45 m. Locally abundant. Collected for food in the Gulf of Thailand andsouthern Viet Nam. Restricted to the tropical western Pacific, from eastern Thailand to thePhilippines; north to Taiwan Province of China and south to Indonesia. Perhaps also occurring inthe eastern Indian Ocean.





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260 Bivalves

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CARDIIDAE posterior cardinal tooth D · anterior and posterior lateral teeth, typically present in...

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