Bivalves are a group of marine and freshwater animals known for their two-part shells, which are hinged together. Common examples of bivalves include clams, oysters, and mussels. They live in various environments, from sandy beaches to deep ocean floors, and play important roles in their ecosystems by filtering water and providing habitat for other creatures. These animals are primarily filter feeders, meaning they obtain their food by filtering plankton and other small particles from the water. Bivalves are also significant to humans, as they are a popular source of food and are harvested for their shells, which can be used in jewelry and decoration.