This symbiotic relationship is so important that coral will die without light. The structures created by classification can vary in size up to several hundred tons. The shape of the coral is determined by the species of coral that created them. Individual coral resemble sea anemones. Tentacles containing stinging capsules called nematocysts are used to capture small plankton or small organisms.
Coral have both asexual and sexual reproductive strategies.
Asexually, coral can break apart in clonel fragments traveling short distances. Sexually, coral produce larvae from the gametes produced by the coral. These two sexual strategies have been very important for the historical survival of coral. Corals have survived over 200 million years. Adaptations such as the calcification and symbiotic relationships developed early are particularly important for this survival.