(1) Prawn belongs to the phylum arthropoda. Prawn is a common name for small aquatic crustaceans with an exoskeleton and ten legs (i.e. a member of the order decapoda), some of which can be eaten. Crustaceans form a large, diverse arthropod taxon which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill, woodlice and barnacles.