Crustaceans

A class of arthropod, a group of animals that have external skeletons or shells, segmented bodies, and jointed appendages. Lobsters, crabs, prawns, langoustines, crayfish, and shrimp are examples of commonly used crustaceans. All crustaceans share the same basic anatomy, made up of roughly two parts: the cephalothorax and the abdomen. The cephalothorax is the equivalent of the human head and trunk, composed of major organs and appendages, while the rear portion, or abdomen, is considered the tail, and is mostly composed of muscles for swimming.