List any four salient features of phylum colelenterata.

Explanation

1. Coelenterates are all aquatic, most of them are marine and a few are fresh water forms.
2. Members are multicellular and the cells are compactly arranged to form definite tissues.
3. Coelenterates exhibit radial symmetry.
4. These organisms have two germ layers viz outer ectoderm and inner endoderm, and thus they are diploblastic. Between these two cellular germ layers, is a thick non-cellular gelatinous mesoglea.
5. Two distinct types of individuals are seen in poly or hydra like (hydroid) type and the medusoid type.
6. Some forms exhibit polymorphism (eg : Obelia).
7. Digestion is both extracellular and intracellular.
8. Reproduction takes place by both sexual and asexual methods.