Bivalves: Bivalvia

Bivalves are found worldwide in freshwater and ocean habitats.

All bivalves need fresh or sea water to breathe, reproduce, and feed. Ocean-dwelling species are found from the seashore to deep-sea habitats. However, the Australian Enigmonia lives on mangrove leaves or seawalls beyond high tide and gets its moisture from sea spray. Most species live on the bottom or burrow into mud and sand. Others attach themselves to rocks, wood, and other solid objects. A few burrow into rock and wood or live on the bodies of other animals.

Most bivalves eat bits of plants and animals floating in the water. A few species collect food from the bottom. Others absorb nutrients directly into their bodies or capture small crustaceans and worms by grabbing them with a special intake siphon.