Phylum – Coelenterata or Cnidaria

Phylum – Coelenterata or Cnidaria

All coelenterates are aquatic animals, they are mostly marine in habitat. The body symmetry is radial. The body wall is of two layers of cells namely the outer ectoderm and the inner endoderm, which is separated from each other by a non-cellular jelly-like substance called mesoglea. Due to the presence of two layers in the body wall, they are said to be diploblastic animals. Many coelenterates exhibit polymorphism. In this phylum, organisms may exist in two different body forms namely, a polyp and a medusa. The tentacles bear stinging cells called nematocysts (cnidoblasts). Due to the presence of cnidocil, they are also called as Cnidaria. They reproduce both asexually and sexually.