Bivalves are molluscs whose shells consist of two hinged valves that open and close around the animal. Most bivalves are filter feeders, drawing in water through a siphon into the gills, and then expelled through another siphon. This process provides the bivalve with both food particles and oxygen. Some bivalves live entirely embedded in substrate, with only the siphons protruding.

Ark Shells (Order Arcida)

Clams (Order Cardiida)

Mussels (Order Mytilida)

Oysters and Allies (Order Ostreida)

Scallops and Allies (Order Pectinida)