a starfish of the phylum Echinodermata measuring as much as 50 cm across. A. planci is found on coral reefs in the tropical regions of the Pacific and Indian oceans. Its body is covered with numerous sharp needles reaching 3 cm in length. Stings are extremely painful and cause severe poisoning in humans. The starfish feeds on polyps and madrepores. In the 1960’s massive numbers of the starfish appeared in many regions and caused the complete destruction of corals on extensive areas of reefs (for example, on Guam, in some areas of the Great Barrier Reef of Australia, and on the Fiji Islands). The principal control measure is the destruction of the starfish with injections of Formalin, which are administered by teams of divers.