Pascal Kobeh / Close-up of the head of Bullethead parrotfish (Chlorurus sordidus) sleeping at night in its mucus cocoon, Great Barrier Reef, Australia. Coral sea.

Pascal Kobeh / Close-up of the head of a Bullethead parrotfish (Chlorurus sordidus) sleeping at night, Great Barrier Reef, Australia. Coral sea.

David Fleetham / Bullethead parrotfish (Scarus / Chlorurus sordidus) biting into coral heads, Hawaii. They extract the organic matter and expel the remains.

David Fleetham / Male Bullethead parrotfish (Chlorurus spilurus), terminal phase, resting on a reef, Hawaii, Pacific Ocean.

David Fleetham / Bullethead parrotfish (Chlorurus spilurus) male, in terminal phase, over reef. Pacific Ocean, Hawaii.