Octocorallia
Alcyonacea
Helioporacea
PennatulaceaHexacorallia
Actiniaria
Antipatharia
Corallimorpharia
Scleractinia
Zoantharia
Corals are marine invertebrates in the class Anthozoa of phylum Cnidaria. They typically live in compact colonies of many identical individual polyps. The group includes the important reef builders that inhabit tropical oceans and secrete calc ... Show More