ZOOLOGY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site coral Large star coral, Montastrea cavernosa. Image credit: USGS The calcareous skeleton or fused skeletons of various cnidarians or the skeleton together with the animals (polyps) that secrete it. Coral-making organisms belong to the class Anthozoa, which also includes the sea anemones. Most corals join together in colonies and secrete external limestone skeletons, forming reefs. Branches and successive layers are formed by budding and by the addition of new members produced sexually which swim freely before attaching themselves and secreting their skeletons. Older members of the colony gradually die, leaving their skeletons behind. Vegetation, such as coraline algae, cements the discarded skeletons, forming coral reefs, of which there are three types: fringing reefs along the shore, barrier reefs offshore, and atolls. Related category    • ZOOLOGY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP