Washington Clam Shell, Saxidomus nutalli

Washington Clam Shell, Saxidomus nutalli. Shell collected off the beach in the greater San Diego area, San Diego, California, March 2018. Size: 12.4 cm (4.9 inches) x 8.8 cm (3.5 inches). Collection, photograph and identification courtesy of Bob Hillis, Ivins, Utah.

The Washington Clam Shell, Saxidomus nutalli (Conrad, 1837), is bivalve mollusk that is a member of the Veneridae Family of Venus Clams. The shell is sturdy shell with an oval profile that is moderately inflated with prominent beaks. The exterior of the shell is sculpted with fine, but sharply defined, concentric ridges. The exterior is covered with brown periostracum and when removed is light grayish to brown color, often with a rusty wash; the interior is whitish, sometimes with a purple wash. The Washington Clam shells reach a maximum of 15.6 cm (6.1 inches) in length and 11.1 (4.4 inches) in height.

Washington Clams are found buried in sand or mud substrate, usually in protected waters, intertidally to depths up to 10 m (35 feet). They range from Northern California to Punta Eugenia, Baja California Sur. They are not known residents of the Sea of Cortez.

Synonyms include Saxidomus arata, Saxidomus aratus, Saxidomus squalidus, and Tapes gracilis.