Starfish belongs to the phylum echinodermata who have developed tube feet for locomotion. The tube feet generally protrude out through special radial areas called ambulacra. They are extended and retracted by variations in hydraulic pressure of fluid in them and by contractions of their muscles. Cuttle fish belongs to the phylum mollusca and it swims. Crayfish belongs to the phylum arthropoda in which locomotion occurs by jointed appendages. Jelly fish belongs to the phylum cnidaria and it swims.