Coral Systematics

The Phylum Cnidaria contains three classes that differ depending on which phase of the life cycle, the polyp or medusa, is expressed. In general, the polyp form is anchored with tentacles pointing upward and the medusa form is free-floating with tentacles pointing downward. Stinging cells, or nematocysts, are characteristic of the Cnidarians. The three classes are:

Last updated on October 17, 1997-jlc.