GENERAL HISTOLOGY

Detailed explanation-1: -Sea stars, commonly called, “starfish, ” are not fish. Sea stars live underwater, but that is where their resemblance to fish ends. They do not have gills, scales, or fins. Sea stars live only in saltwater. Sea water, instead of blood, is actually used to pump nutrients through their bodies via a ‘water vascular system.

Detailed explanation-2: -Crabs, lobsters, shrimps, and wood lice are among the best-known crustaceans, but the group also includes an enormous variety of other forms without popular names.