Anthozoans
| Anthozoa Temporal range: 570–0 Ma Late Ediacaran to recent |
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| Coral outcrop on the Great Barrier Reef |
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| Gorgonian with polyps expanded | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: |
Anthozoa Ehrenberg, 1834 |
| Subclasses | |
Anthozoa is a class of marine invertebrates which includes the sea anemones, stony corals, soft corals and gorgonians. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as part of the plankton. The basic unit of the adult is the polyp; this consists of a cylindrical column topped by a disc with a central mouth surrounded by tentacles. Sea anemones are mostly solitary, but the majority of corals are colonial, being formed by the budding of new polyps from an original, founding individual. Colonies are strengthened by calcium carbonate and other materials and take various massive, plate-like, bushy or leafy forms.
Anthozoa is included within the phylum Cnidaria, which also includes the jellyfish, box jellies and parasitic Myxozoa and Polypodiozoa. The two main subclasses of Anthozoa are the Hexacorallia, members of which have six-fold symmetry and includes the stony corals, sea anemones, tube anemones and zoanthids; and the , which have eight-fold symmetry and includes the soft corals and gorgonians (sea pens, sea fans and sea whips), and sea pansies. The smaller subclass, Ceriantharia, consists of the tube-dwelling anemones.
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