Introduction of Echinodermata

The word echinodermata is derived from two Greek words echinos which means hedgehog and derama which means skin. These are animals which are mostly marine living on the shore but mostly on the bottom of the sea.

These are animals whose body can be divided into five parts arranged around a central axis but its larva is divided into two equal parts.These are animals which consists of calcareos exoskeleton. These animals have separate sexual organs and no copulation takes place .The gonads discharge their gametes to outside and fertilization takes place in the sea water.

                                             Echinodermata are widely distributed and contains 5300 species.The phylum is divided into two sub phyla namely Pelmatozoa and Eleutherozoa. The Pelmatozoa has only one living class called Crinoidea while Eleutherozoa has four living class namely Holothuroidea, Echinoidea, Asteroidea and Ophiuroidea