Acanthaster planci prey on coral polyps. It digests its food by climbing onto its prey and extruding its stomach over the coral colony, releasing digestive enzymes to then absorb the liquified tissue. They feed solitarily at night and maintain a constant distance between themselves and other Acanthaster planci. Individual starfish feed on up to 13 square miles of coral per year. During times of food shortage, these animals can live on energy reserves for over six months at a time. However, a proliferation of this species can be detrimental to the survival of coral reefs. In recent years Acanthaster planci have reduced the colorful attraction of the Great Barrier Reef with its ravenous appetite (Johnson, 1996; "Cnidarians", 2000; Perrins and Middleton, 1985; Schmid, 1998; "Great Barrier Reef", 2000)