Considered the most diverse of the marine ecosystems, the coral reef is comparable in terms of wealth to its terrestrial equivalent : the tropical forest. Like it, it constitutes a center of exchange, cohabitation, alimentation and reproduction for thousands of animal or plant species. The corals which build it are marine animals belonging to the Cnidarians, these soft-bodied animals with stinging parts such as the gorgonians, jellyfish and sea anemones.