what type of protection does a bivalves have?
Bivalvia is a class of mollusks that all have two shells. It includes the clams, oysters, scallops and mussels. There are over 20,000 species of bivalves around the world, and probably thousands not yet discovered.Nearly all of them live in salt water, but a few groups have evolved to live in freshwater.Bivalves have two shells that they can close together tightly for protection, with their whole body inside.here are over 20,000 species of bivalves around the world, and probably thousands not yet discovered. Nearly all of them live in salt water, but a few groups have evolved to live in freshwater. Bivalves have two shells that they can close together tightly for protection, with their whole body inside.