Convict Tang

The Convict Tang is a widely distributed surgeonfish (family Acanthuridae) named for the six to seven bold black bars crossing its pale body, resembling a striped prison uniform. Found throughout the Indo-Pacific and into parts of the eastern Pacific, it is one of the most abundant herbivorous reef fish in shallow water. It is a key algae grazer, often forming large schools that sweep across reef flats to feed, a behavior that helps control algae growth and maintain reef health. Known locally in Hawaii as "manini," the species holds cultural significance and remains common and widespread, showing no signs of population decline.

• Body: Oval, deep, and laterally compressed, typical surgeonfish shape
• Color: Pale gray to whitish base
• Markings: Six to seven bold black vertical bars crossing the body from head to tail base
• Tail spine: A small, sharp, scalpel-like spine at the base of the tail, characteristic of all surgeonfish, used defensively
• Size: Grows to about 27 cm The evenly spaced black-and-white barring is diagnostic and easily separates this species from other tangs and surgeonfish, most of which lack this striped pattern.

Convict Tangs are found across a broad range spanning the Indo-Pacific, from East Africa to Hawaii and Central America, one of the most widely distributed surgeonfish. They inhabit shallow reef flats, surge zones, and rocky shorelines, typically at depths of less than 5 meters, though they can be found down to about 90 meters. Water temperatures across their range are generally 22-28°C. Juveniles are especially common in very shallow, wave-exposed tide pools and reef flats, while adults may move to slightly deeper reef edges, both stages favoring areas with abundant turf algae for grazing.

Convict Tangs are highly social and are frequently seen in large, coordinated schools that move across reef flats grazing turf algae from rock and coral surfaces. Schooling is thought to help overwhelm the territorial defenses of damselfish that otherwise guard algae patches, allowing convict tangs to feed efficiently even in contested areas. They are most active during the day, retreating to reef crevices at night for safety. Spawning occurs in groups, typically timed with dusk or specific lunar phases, when large aggregations release eggs and sperm into open water, producing pelagic larvae that can disperse over long distances before settling onto new reef habitat.