Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii (ray-finned fishes)
Order: Perciformes (Perch-likes)
Family: Acanthuridae (Surgeonfishes, tangs, unicornfishes)

Genus/species: Acanthurus triostegus

Convict surgeonfish 8156826256_a90f659c94_o

GENERAL CHARACTERISTICS: The Convict Tang is a very common surgeonfish.  It is oval in profile and laterally compressed, gray with 4 vertical stripes (1 stripe on head across the yellow eye; 1 on caudal peduncle). The erectile spine on each side of caudal peduncle which folds down into a groove.  This scalpel like spine causes a nasty cut if the fish is treated roughly by a predator or a human. 

Common length : 17.0 cm (6.7 inches).

DISTRIBUTION/HABITAT:  A. triostegus is found in lagoons and seaward reefs in areas of hard substrates from sea level to 90 m (300 feet) in the Indo-Pacific.

Typically occurs in shallows to 5 m (16 feet).

DIET IN THE WILD: It is a herbivore which uses its serrated teeth along creating saw-like motion to remove filamentous algae from the substrate.


REPRODUCTION: The Convict Tang spawns at dusk with females broadcasting eggs into open water where the males fertilize them.  Larvae drift ~75 days. Post-larvae settle in intertidal areas of benches and reef flats.

PREDATORS: Eggs and sperm are preyed upon by eagle rays, which are often present during spawning.

CONSERVATION: IUCN, Least concern.

REMARKS: This black-barred fish’s common name presumably alludes to the coloration of many prison uniforms of the previous century.



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