Description
Shell sculpture tends to be primarily concentric, but radial and divaricating ornamentation (see Gafrarium), and rarely spines (Pitar lupanaria for example) occur on some. One small subfamily, Samarangiinae, is created for a unique and rare clam found in coral reefs with an outer covering of cemented sand or mud that texturally camouflages it while enhancing the thickness of the shell. Several Venerid clams have overall shell shapes that are adapted to their environment. Tivela species, for example, have the triangular outline of the surf clams in other bivalve families, and occur often in surf zones. Some Dosinia species are almost disc-like in shape and reminiscent of Lucinid bivalves; both types of circular bivalves tend to burrow relatively deeply into the sediment. Further reclassification is to be expected as the results of current research in molecular systematics on the group appear in the literature.
Venerids have rounded or oval solid shells with the umbones (projections) inturned towards the anterior end. There are three or four cardinal teeth on each valve. The siphons are short and united, except at the tip, and are not very long. The foot is large.
Read more about this topic: Veneridae
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