Crown-of-thorns starfish outbreak coral reef slope

The crown-of-thorns starfish is a corallivore, which means that it feeds on live coral tissue. After climbing on a coral colony, it extrudes its stomach and spreads it over the surface of the corals. The stomach secretes digestive enzymes that liquefy the coral tissue which is then absorbed. After this process, the coral colony is left devoid of living tissue and only the white skeletons of the colony remain. On the skeletons, the starfish leave behind observable feeding scars which mark the paths of their destruction. Without the living tissue, the skeletons become more vulnerable and brittle, and are often colonized by non-reef building organism such as algae.
 
Under certain conditions periodic population explosions of crown-of-thorns starfish can occur on reefs, generating alarm due to the extensive damage they can unleash to the corals and the reef ecosystem.
 
Scientific Name: Acanthaster planci