1. Cnidaria - hydras; polyps; jellyfishes; sea anemones; corals Coelenterata, phylum Cnidaria, phylum Coelenterata Metazoa, subkingdom Metazoa - multicellular animals having cells differentiated into tissues and organs and usually a digestive cavity and nervous system Cnidarian, coelenterate - radially symmetrical animals having saclike

2. Phylum Coelenterata (Cnidaria) is a diploblastic metazoa with tissue grade of construction having nematocyst and a single gastrovascular cavity.

3. The Coelenterates or cnidaria are distinguished from sponges in being “tissue animals” (Metazoa) that have distinct digestive cavity

4. 28 The biofilm microscopic observed results indicated that biofacies were quite rich in the biofilm, including all kinds of bacteria, fungus rubber group, protozoa, metazoa and so on.