Spisula elliptica

(Brown, 1827)

Description (shell):
Shell thin, elongate oval, umbones close to midline. Sculpture of fine concentric lines and grooves, growth stages clear. Lunule and escutcheon poorly defined, the former perhaps most distinct. Right valve with two separate, but closely spaced cardinal teeth and paired, elongate anterior and posterior laterals. Left valve with three cardinal teeth: the anterior two forming a single forked structure extending almost to edge of the hinge plate, the third small and indistinct; with single anterior and posterior laterals. Interlocking surfaces of lateral teeth serrated. Chondrophore posterior to cardinal teeth. Adductor scars and pallial line distinct, pallial sinus oval, extending to a point below and beyond midline of posterior lateral teeth (S. elliptica-drawing).

Up to 30 mm long.

Dull white with greenish or greyish brown periostracum. Inner surfaces glossy, white.

The animal has a thick mantle with fringed edges. The siphons are short and united throughout their length, but the exhalent tube is fitted with a tubular valve. The foot is large, tongue shaped and very extensible, used for burrowing and leaping (S. elliptica-animal).

In mixed soft substrata, offshore to about 100 m.

Common in the whole North Sea (Distr. S. elliptica). Distributed northwards to the Barents Sea.