Madracis pharensis (Crusty Pencil Coral) is a species of cnidarians in the family Pocilloporidae. Crusty Pencil Coral formmarine reefs. Individuals can grow to 330 µm.
Definition: A sheet of saline water separated from the open sea by sand or shingle banks. The sheet of water between an offshore reef, especially of coral and mainland. The sheet of water within a ring or horseshoe shaped atoll.
Definition: A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)