Question

List the various systems and characteristics of the major coelomate animal group, Echinoderms (starfish group). List the systems: skin/skin structures, skeleton, movement/type, digestive, respiratory, excretory, circulatory, habitat, mode of existence.

Answer 1

Skin	Echinoderms have ,Spiny skin. The skin contains spines, tube feet and pedicellariae. Pedicellariae help in capturing prey, cleaning.
Skeleton	It consist of endoskeleton made of calcareous Ossicles.
Movement	For movement there is presence of tube feet at end of network of water canal system. They contain sucker that helps in movement.
Digestive System	Digestive system is complete but simple. It has mouth, stomach, Intestine and anus.
Respiration	Respiration usually occurs through body surface as gases diffuses through it.
Excretion	Excretory system is absent. Excretion occurs through skin through diffusion.
Circulation	Water canal system present for circulation, which extends to tube feet on 5 arms.
Habitat	Exclusively Marine
Mode of existence	Solitary, Benthic(Living at bottom), Pentaradial symmetry