Coral Reefs, What They Are and How They Work

Coral is basically a plant with a mouth on one end and a stomach on the other, and yeah that's basically it. As more and more of these coral gather, they form colonies and eventually reefs. Corals eat very small animals floating by stinging them with their barbed mouths, or tentacles, but that is not their only source of food. Corals also get their food from zooxanthellae (which are what actually give the coral their color, since coral are translucent), which are tiny single celled algae which share a symbiotic relationship with the coral. The algae perform photosynthesis and give food to the coral and the coral in turn give the algae nutrients. Coral reefs get their structure from the hard bases of each coral, called the calicle which is a kind of limestone skeleton that provides structure for the coral.