Sunset Clams of the Psammobiidae Family

Two Sunset Clam Shells from the Psammobiidae Family can be found in this website:

Phylogeny: Sunset Clams of the Psammobiidae Family are bivalve mollusks in the Cardiida order. Shells in this order are limited to marine environments. Order Cardiida consists of two superfamilies – Cardioidea and Tellinoidea. The Psammobiidae Family is one of five families in the Tellinoidea superfamily. The Psammobiidae Family is medium-sized, with no subfamilies, twelve genera, and one hundred fifty-three species. Shells in this family are also commonly called Psammobiids.

Description: Sunset Clams derive their name from the often colorful, radial, rays on the shell’s exterior that project from the beak. The shells are thin and have an elongated oval or trapezoidal outline. They are fairly flattened in profile. The beaks are relatively centered and have one to three cardinal teeth. In some species there is a narrow gap between valves. Most species in the family are equivalve (both valves equal in size and shape). Generally, Sunset Clams have a smooth exterior or weak commarginal lines, though some have radiating ribs. The interior is porcelaneous. Many Sunset Clams are covered, at least partially, by a periostracum.  These mollusks have long siphons and a strong foot to facilitate burrowing. Sunset Clams are small to large-sized, with the larger species reaching  14 cm  (5.5 inches) in height.

Habitat and Distribution: Sunset Clams live buried in soft substrates. They are found from the intertidal zone to depths of 150 m (490 feet). Sunset Clams are found worldwide in tropical to temperate seas. Ten ten species of the Psammobiidae Family are found in Mexican waters.

Natural History: Sunset Clams may be suspension feeders or deposit feeders, using their siphons to suck up plankton and detritus that drifts by or that is laying on the surface of the substrate. In turn, they are preyed upon by crabs, predatory mollusks, rays, sea stars and shorebirds. These shells are gonochoric and reproduce through broadcast spawning. Sunset Clams are edible and some Asian species are considered delicacies.