Pacific Northwest Molluscs
Last modified on July 24, 2003.
Molluscs are soft bodied animals lacking backbones. Hence they
are invertebrates. Their soft body is covered by a mantle which in most species,
secretes a calcareous shell. All have a strong, muscular foot used for locomotion,
digging, or predation. Most are aquatic, such as the bivalves (clams, mussels,
scallops, etc), and cephalopods (squid, cuttlefish, nautilus, and octopi). The
gastropods (snails, sea slugs, and slugs) are also largely aquatic, but many forms
are also terrestrial.
Freshwater Mussel (clam):