<p><span class="taxon"><em>Acanthaster planci</em></span> 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. <span class="taxon"><em>Acanthaster planci</em></span> 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).</p>