Classes into which the phylum is divided

Question

What are the main classes into which the phylum is divided? What are some examples of each and in which form (polyp or medusae) are they found?

Answer 1

Coelenterates are classified into three main classes: scyphozoans, hydrozoans and anthozoans. In hydrozoans, the polypoid form predominates and illustrations are hydras, by-the-wind-sailors and Obelia. In scyphozoans the major phase is the medusoid and the best known illustration is the common jellyfish (or Aurelia). In anthozoans there is just the polypoid form and corals and sea anemones and are notable in this class or category.