Acanthaster planci are red colored echinoderms protected by thorn-like spines. They grow to a diameter up to 40 cm across. They have 12-19 arms extending from their center. These animals do not have a head, and are pentamerically symmetrical about the axis of the mouth. Acanthaster planci have tubed feet, or branched tentacles arranged along each arm that function in gas exchange and food gathering (Schmid, 1998; Perrins and Middleton, 1985; Encyclopedia Britannica, 2000).