Cerastoderma edule

(Linné, 1758)

Description (shell):
Shell broadly oval. About 24 broad ribs, and closely spaced concentric ridges; ridges on ribs may be developed as flattened, scale-like spines. Growth stages distinct. Each valve with two small cardinal teeth; right valve with two anterior and two posterior laterals. Adductor scars and pallial line distinct; in larger specimens the posterior adductor and areas around it, may be tinted chestnut or light purple. External sculpture visible as grooves extending from ventral margin, fading rapidly beyond pallial line (C. edule-drawing 2).

Up to 50 mm long.

Cream, light yellowish, or pale brown; periostracum yellowish or greenish. Inner surfaces dull white, brown, thin (C. edule-drawing).

The animal has a white body, but the mantle is pale yellow, its edges with a short white fringe. The short siphons are separate throughout, with white filaments along their sides. The white or yellow foot is proportionately small, though long, and ends in a thin flat point (C. edule-animal).

In sandy mud, sand or fine gravel, from mid-tidal level to just below ELWS. Tolerant of salinities as low as 10ä and often abundant in sheltered bays and estuaries.

Common in the North Sea (Distr. C. edule). Distributed from north-east Norway to West Africa.