The crown-of-thorns starfish, Acanthaster planci, is a large, multiple-armed starfish that usually preys upon hard, or stony, coral polyps. The crown-of-thorns starfish receives its name from venomous thorn-like spines that cover its upper surface, resembling the biblical crown of thorns. It is one of the largest starfish in the world. A. planci has a very wide Indo-Pacific distribution. It is perhaps most common in Australia, but can occur at tropical and subtropical latitudes from the Red Sea