Astarte sulcata

(da Costa, 1778)

Description (shell):
Shell thick and robust, broadly oval, prominent umbones imparting subtriangular outline. Lunule and escutcheon distinct, deep; ligament visible in anterior half of escutcheon. Sculpture of bold concentric ridges, growth stages indiscernible. Left valve with two prominent cardinal teeth below umbones and a third, slender, indistinct and often abraded, extending below ligament. Right valve with very thick anterior cardinal tooth and slender one posteriorly; additionally, slender ridge below escutcheon may be taken for posterior lateral tooth. Adductor scars and pallial line very clear, inner shell margin distinctly crenulate, rarely smooth (A. sulcata-drawing).

Up to 30 mm long.

Usually white (rarely pink) with thick, mid- to dark-brown periostracum, often encrusted and stained black about umbones. Inner surface of shell dull white, often with pink or brown tinge.

Body almost round, flattened from the sides. The lips are large; the mantle is thick, not fringed with tentacles, but part of it forms a short excretory siphon behind. The foot is conical and small, though powerful.

In mud or fine gravels with sand, shells, or mud, offshore.

Distributed from southern Arctic waters to the Mediterranean and north-west Africa (Distr. A. sulcata).