The Moorish Idol has a very long, white, sickle-shaped dorsal fin, two broad black bars on the body, and a yellow saddle across the snout.
It uses its long snout to feed on coralline algae and sponges in cracks and crevices.
The Moorish Idol grows to 24cm in length.
It is sometimes seen as a single individual, but often forms pairs and occasionally larger schools.
This species has a widespread Indo-Pacific distribution in tropical and some temperate waters.
In Australia it is known from the central Western Australian coast, around the tropical north and south to southern New South Wales . It can be found from the shallows to depths in excess of 180m.
The genus name " Zanclus " comes from the Greek word for "sickle" and refers to the sickle-shaped dorsal fin. The species name " cornutus " is from the Latin word for "horn", and presumably refers to the bumps over the eyes of adults.
The Moorish Idol is the only species in the family Zanclidae.