Bivalves are a group of marine and freshwater animals known for their two-part shells, which are hinged together. Common examples 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 have a simple body structure, with a soft body protected by their hard shells. Bivalves feed by filtering tiny food particles from the water using their gills. They are also a popular food source for humans and are harvested in many parts of the world for their delicious meat.