The corals appear like mushroom. Fungia species are solitary and lie free on the substrate. They are known to be able to move about on a reef. Other important mushroom corals are Heliofungia actinimorphis, Herpolitha Umax and Polyphyllia talpina.
Brain corals are large boulder -shaped corals with appearance of brain. Some brain coral species are Lobophyllia sp., Symphyllia sp. etc.
Octo coral has a hard skeleton arranged in upright elongated flat curved plates. It contains an iron pigment and internally is coloured blue. The external colour is light grey.
The group of animals and plants found in a reef is known as the reef community.
Reef builders comprise organisms which contribute to the building of a reef. Their lime-stone skeletons are the major component of the calcareous matter which forms a coral reef. Another reef builder is the calcareous red algae which help in binding coral skeleton and strengthen them against erosion. In addition, some green algae help in consolidating reef sediments.
Reef dwellers do not help in reef formation but take part in energy transfer in a reef community's food webs. They may be either resident species which remain in the reef throughout their life or may be visiting species which spend only part of their lives in the reef, often for breeding purpose or for searching specific food available in the reef.
Common Coelenterate Reef
These coral dwellers are jelly fish and sea-anemone. The jelly fishes do not stay around coral reefs all the time but during certain season they appear in large number. Some are capable of inflicting very severe stings which can cause shock to swimmers who are allergic.
Crustacean Dwellers in Coral reefs
The crustacean dwellers include a variety of crabs, lobsters and shrimps. The mollusks include the Top Shell, Turban Shell, Sacred Chunk, Cowries, Black Lip Pearl Oyster, Giant Clam etc.
Star Fishes in Coral reefs
The echinoderms include common star fish and brittle stars. These are the popular star fishes. These star fishes are residing here.