Mention the important characters of the phylum Echinodermata and give examples
The important characters of phylum Echinodermata are: - (i) The term Echinodermate means "spiny skin," and it refers to a group of animals represented by common forms such as starfish and sea urchins. (ii) The skin forms a hard, spiny protective skeletal covering. (iii) They are sluggish marine forms. (iv) They usually show pentamerous radial symmetry. (v) The radial symmetry is superficial and the body in fact can be divided only into two halves. (vi) They have a coelom as well as a water vascular system. Locomotion takes place through the use of numerous hollow tube feet. (viii) Excretion occurs by means of diffusion through the body. (ix) Fertilization occurs in the open sea. (x) The development includes free swimming diploneural larva. (xi) Example: - Asterias, Sea Urchin and Sea cucumber.
