Classification |
Corals and other polyps belong to the phylum
Cnidaria, which composes a large invertebrate group containing stone
corals, sea anemones, jellyfishes and their relatives. All cnidarians have
the following characteristics in common: they are radially symmetrical,
they lack a head, they posses nematocysts, and they usually have a crown
of tentacles around their mouths. About 9000 living species of cnidarians
are known.
All reefbuilding and non-reefbuilding(soft-corals) corals belong to the class Anthozoa, of which there are about 6000 species. Corals comprise about 2500 species. Within the class anthozoa are different sub classes with different characteristics: the Octocarallia (characterized by having eight side-branching tentacles, this sub class is exclusively made up of soft corals that are mostly colonial), the Zoantharia(these polyps have tentacles in a multiple of six, and this sub class contains the stone corals, that may be either colonial or solitary). |