The adults have a bulging protuberance on the front of the head, in larger males this may extend beyond the mouth.

There is a pair of bony plates on either side of the caudal peduncle and each has a forward projecting point.

There is an irregular pattern of pale and black spots below the spiny part of the dorsal fin.

In the Western Indian Ocean it ranges from the eastern coast of Africa between Somalia and KwaZulu-Natal, Madagascar, the Comoros, the Seychelles and the Mascarenes.

[7] This species is often solitary but may be found in small groups on coral reefs where they feed on zooplankton and algae.