Coral Reefs

The polyp is the basic body form of the Anthozoans and a coral polyp is comprised of a small cylindrical body with a central gastro vascular cavity divided into partitions by septae. The body is topped with a ring of tentacles which are used to capture food from the surrounding waters. The tentacles encircle a small opening which acts as both a mouth and an anus.

Anthozoans are further divided into two main groups, the Octocorallia (or Alcyonaria) and the Hexacorallia (or Zoantharia). Octocoral polyps have eight tentacles and body partitions, or multiples thereof, and are all colonial. Perhaps the best known members of this sub-class are the sea fans and soft corals. Hexacoral polyps have six tentacles and body partitions, or multiples thereof. Many coral species in this group have developed the ability to live in colonies, with often thousands or millions of tiny polyps making up one coral colony, although some species are solitary.