GEORGETTE DOUWMA / SCIENCE PHOTO LIBRARY GEORGETTE DOUWMA / SCIENCE PHOTO LIBRARY
Blacktongue unicornfish (Naso hexacanthus) being cleaned on a reef. This tropical fish is found in coral reefs in the Pacific and Indian Oceans, and is capable of dramatic colour changes. Photographed in the Maldives.
Model release not required. Property release not available.