Twospot Bristletooth (juvenile)

Ctenochaetus binotatus is a tang fish native to the Indo-Pacific region, excluding the Red Sea, Hawaii and the Marquesan Islands.

Other names: Twospot Surgeonfish.

Description

It has a prominent black spot at the rear base of dorsal and anal fins. Adults have a bluish ring around the eye. Dorsal and anal fins dark brown. Characterized further by orange-brown body color with pale spots on head and breast; side of body with longitudinal pale lines. 
Juveniles have dark brown to black body color with blue spots on head and breast, faint blue lines on body. Caudal fin is brown in adults, yellow in young. Edge of lips smooth. Upper teeth usually with 5 denticulations (not including tip). Anterior gill rakers 23-29.

It can grow to 22 cm in length.

Distribution

Indo-Pacific: East Africa to the Tuamoto Islands, north to southern Japan, south to central New South Wales (Australia) and New Caledonia.

Not known from the Red Sea, Gulf of Oman, the Gulf, the Hawaiian Islands, Marquesas, Rapa, Pitcairn Islands, and Easter Island.

Habitat

It is a reef fish occurring at depths from 10–50 m (33–164 ft). It occasionally makes its way into the aquarium trade.

Inhabits coral and rubble areas of deep lagoon and seaward reefs. Usually solitary, grazing on surface algae. Feeds by scooping film of detritus and unicellular algae (e.g. dinoflagellate Gambierdiscus toxicus) that produce ciguatera toxin making this species a key link in the ciguatera food chain.