Shell large, solid, equivalve, inequilateral. Outline almost rectangular, longer than high. Beaks at the anterior 1/3, pointing towards the front. Coarse sculpture of numerous radial and concentric striae which become nodulose at the point of intersection; radial ribs slightly more prominient than concentric ones. Lunule narrowly heart shaped. Pallial sinus heel-shaped. Internal margin smooth.
extremely variable in color and pattern. Exterior generally cream, variously rayed, banded or blotched with brown. Interior white to pinkish-white; within the pallial line flushed with pale yellow.
common size :
shell 25-57 mm in length. Commercial size ca 40 mm.
Similar to the native Tapes decussatus (Linnaeus, 1758) from which it is distinguished by the much more pronounced decussate sculpture, the more angulated shell both posteriorly and anteriorly and the almost fused siphons.
BIOLOGY / ECOLOGY
Studies carried out in Thau/France and Venice (Italy) lagoons revealed that the best growth period is during phytoplankton bloom (spring and autumn) at temperatures between 10 and 20°C and the reproduction period extends from May to October (Maitre-Alain, 1983, 1985).
brackish waters species. Burrows in sand or muddy-gravel bottoms below the mid tide level to a few meters deep, usually in quiet waters. From the intertidal zone to 4 m deep.