Bivalve

[Sarah]

A mollusk having a shell consisting of two lateral plates orvalves joined together by an elastic ligament at the hinge, which isusually strengthened by prominences called teeth. The shell is closedby the contraction of two transverse muscles attached to the innersurface, as in the clam, -- or by one, as in the oyster. SeeMollusca.

[Merna]

a type of mollusc , such as an oyster , that has its body inside two connected shells:

[Greta]

An aquatic mollusk that has a compressed body enclosed within a hinged shell, such as oysters, clams, mussels, and scallops.