These animals have a soft, unsegmented body, with a hard, calcareous shell to protect the soft body. They have a muscular foot to help in locomotion and also to act as a weapon in some cases.

Examples: snails, slugs, oysters, mussels, clams, squids, and octopuses.

Main Characteristics

  • Unsegmented soft-bodied animals terrestrial or aquatic
  • Exoskeleton in the form of a shell. When present shell is usually univalved or bivalved; internal shell present in some.
  • Sexes separate or united.
  • Have a muscular foot for locomotion.

Examples: Apply snail (Pila), Freshwater mussel (Unio), Cuttlefish (Sepia), Slugs, Octopus.