Large-ribbed Cardita Shell, Cardites crassicostatus

Large-ribbed Cardita, Cardites crassicostatus. Shell collected by the deepwater shrimp trawlers off the southwest coast of Baja California Sur, April 2010. Size: 6.5 cm (2.6 inches) x 6.5 cm (2.6  inches).

The Large-ribbed Cardita, Cardites crassicostatus (G.B. Sowerby I, 1825), is a bivalve mollusk that is a member of the Carditidae Family of Little Hearts. They are also known as the Thick-ribbed Cardita. The shell has a a rounded rectangular profile and is plump and equivalve (both valves equal in size and shape). The exterior displays a dozen or more wide radial ribs, which terminate in a squared-off scalloping at the margin. The exterior of the shell is orange with white and brown blotches and the interior is white. The Large-ribbed Cardita Shell reach a maximum of 6.8 cm (2.7 inches) in length and 6.8 cm (2.7 inches) in height.

Large-ribbed Cardita are found in sand and gravel from the intertidal zone to depths up to 55 m (180 feet). They found from Bahia Willard, Baja California to Cabo San Lucas, Baja California Sur within the Sea of Cortez and south to Peru including the Galapagos Islands; they have not been documented to occur along the west coast of Baja however the shell photographed above was collection along the extreme southwest coast of Baja documented their presence in this area.

Synonyms include Cardita cuvieri, Cardita michilini, Cardita sulcosa, Cardium locinoides, and Venericardia crassicostata.