Ensis siliqua

(Linné, 1758)

Description (shell):
Shell thin and brittle, elongate; dorsal and ventral margins parallel, practically straight, anterior and posterior margins obliquely truncate, with rounded corners. Sculpture of fine concentric lines, following the growth increments (E. siliqua-drawing). Left valve with two projecting, peg-like cardinal teeth and two elongate, posterior laterals, situated one above the other; right valve with a single cardinal and a single, elongate posterior lateral. Adductor scars and pallial line clear; anterior adductor scar elongate, dorsal, extending to behind ligament; posterior scar small and round, separated from pallial sinus (Interior E. siliqua & E. minor).

Up to 200 mm long.

White or cream, with pale purple, pink, or reddish streaks; periostracum glossy, light olive or yellow-brown, grey-green along posterior dorsal region. Inner surfaces white, often tinted blue or purplish.

The animal is of a pale drab colour, with a yellowish, tongue-shaped foot. Except at the fore-end for the passage of the foot, and a minute opening on the lower surface, the mantle-edges are united throughout. The siphons are exceedingly short, united, and their openings are fringed. At the base of these filaments there are grooves in which are situated pigment spots highly sensitive to light. A shadow cast over the bottom is sufficient to cause the sudden disapperance in the sand (E. siliqua-animal).

Burrowing in sand, from the lower shore into the shallow sublittoral.

Distributed from Norway to the Mediterranean and north-west Africa (Distr. E. siliqua).