Biological and ecological information

Species diversity  Corals are invertebrate organism having calcareous skeleton as their hard structure like a bone which is the support of coral tissues. Coral’s shape is similar to a small cylinder with a set of tentacles at the end of cylinder; the tentacles are used to catch plankton in water column as a food. Another coral’s food source is obtained from the nutrients produced by many single-cell algae, called zooxanthellae that live within coral tissues (Figure ). Corals and the algae are lived together as a symbiotic relationship where the algae benefit from a place to live and obtain the carbon dioxide derived and other wastes from the respiration system of corals for the photosynthesis process.

    

Figure 2  Zooxanthellae

Source: http://coralreef.noaa.gov/aboutcorals/coral101/symbioticalgae/resources/zoox_santos.jpg

When considering the surface of coral skeleton, the small pores of 1-3 millimeters wide that the coral polyps are embed inside, can be noticed and the pore size is varied by each species. The shape of these pores may be circle, oval, square or long, where the individual or many polyps can be placed. A stone or plate or branch of corals which are composed of many coral polyps that connected altogether is called “coral colony” (Figure ). The coral colony is resulted from the extension of polyps or cloning reproduction, while some colony formed by an individual coral is called “solitary” such as mushroom coral (Figure).

    

Figure  Coral colony

Figure  Mushroom coral