David Fleetham / Three Sleek unicornfish (Naso hexacanthus) at a cleaning station with a endemic Saddle wrasse, (Thalassoma duperrey) Hawaii.

David Fleetham / Sleek unicornfish (Naso hexacanthus) which has turned a darker than normal colour to help an endemic Hawaiian cleaner wrasse, (Labroides phthirophagus) spot parasites, Hawaii.