The black-spot surgeonfish (Acanthurus bariene) is a reef fish from the Indo-Pacific, recognizable by its brown coloration and the dark spot near the gill opening. Like other surgeonfish, it has a sharp spine on each side of the base of its tail, which it uses for defense.

The black-spot surgeonfish has a relatively deep, laterally compressed body that is generally brown, with a rounded black spot above the gill opening and a dark blue line along the bases of the dorsal and anal fins. A dark brown marking also surrounds the spine on each side of the caudal peduncle, at the base of the tail. The edge of the eye and certain areas of the head may have orange markings.

The black-spot surgeonfish can reach a maximum length of about 20 inches.

The black-spot surgeonfish inhabits tropical waters of the western Indo-Pacific, from Mozambique and the Maldives to the western Pacific, including tropical regions of the Indian Ocean and Southeast Asia.

The black-spot surgeonfish is found in the Seychelles, Mauritius, Sri Lanka, the Andaman and Nicobar Islands, the Philippines, Indonesia, Micronesia, Palau, New Caledonia, and Fiji.

The black-spot surgeonfish inhabits clear waters around coral reefs, particularly along outer slopes and reef walls facing the open ocean. Adults generally live at depths of 50 to 100 feet or more and are observed alone or in pairs.

Juveniles, by contrast, inhabit shallow, sheltered reefs, often among soft corals near the surface.

The black-spot surgeonfish feeds mainly on the film of algae covering rocks and reef surfaces. By grazing on these algae, it finds an abundant food source on rocky bottoms and helps maintain the balance of reef life.

The black-spot surgeonfish is an egg-laying fish with separate sexes. The female releases her eggs into the water, where they are fertilized by the males. The eggs then drift in open water as they develop.

In large males, the forehead becomes very prominent and may extend beyond the tip of the mouth, making this a remarkable feature of the species.

The black-spot surgeonfish is listed as many other marine species within The IUCN Red List of threatened species. The black-spot surgeonfish appears in the IUCN Red List since 2012 within the category Least Concern !