The Crown of Thorns starfish is known for its large size and poisonous spines. It is one of the largest sea stars in the world and usually lives where there are coral reefs. They feed mostly on scleractinia, which are hard corals and marine animals that have built themselves a hard exoskeleton. These sea stars are commonly pictured eating these and turning them into sand dollars. Each starfish has a madreporite, which is a perforated plate. It is a distinguished white spot on the top side of the central disk. It is through here that water is pulled into it’s internal water-vascular system. This water-vascular system helps function with locomotion, feeding, and respiration. Seawater filled ducts run into the stone canal, the ring canal, the radial canals, the lateral canals, and the tube-like suction cup feet.