coelenterate Alternative name for members of the phylum Cnidaria – aquatic animals which include the jellyfish, sea anemone, coral, and hydroids. Characterized by a digestive cavity that forms the main body, they may have been the first animal group to reach the tissue level of organization. Coelenterates are radially symmetrical, jelly-like, and have a nerve net and one body opening. Reproduction is sexual and asexual; regeneration also occurs. There are c.9,000 species.

coe·len·ter·ate / siˈlentəˌrāt; -rət/ • n. Zool. an aquatic invertebrate animal of the phylum Cnidaria (formerly Coelenterata), which includes jellyfishes, corals, and sea anemones. They are distinguished by having a tube- or cup-shaped body. Also called cnidarian.

coelenterate An invertebrate animal with a radially symmetrical body, a body wall consisting of two cell layers, and a body cavity (gastrovascular cavity) that communicates with the outside via a single opening, the mouth. Coelenterates include hydras, jellyfish, sea anemones, and corals (see Cnidaria) and also the comb jellies (see Ctenophora).

Coelenterata The name formerly given to a phylum comprising both Cnidaria and Ctenophora. Today, when these two groups are universally separated in different phyla, the term ‘Coelenterata’ is sometimes used as a synonym for Cnidaria alone.

Coelenterata Name formerly applied to a phylum comprising both Cnidaria and Ctenophora. Today, when these two groups are universally separated in different phyla, the term ‘Coelenterata’ is sometimes used as a synonym for Cnidaria alone.