Convict Surgeonfish
Acanthurus triostegus
Convict Surgeonfish (Acanthurus triostegus) is a small reef-dwelling surgeonfish with bold vertical bars and a sharp tail spine. It grazes on algae in shallow tropical waters and is commonly seen in schools over coral and rocky reefs.
Identification points
- White body with 6-7 dark vertical bars running from back to belly
- Small, oval surgeonfish body with a pointed snout and narrow mouth
- Single sharp yellowish caudal spine on each side of the tail base
Habitat
Shallow tropical reef flats, lagoon edges, seaward reef slopes, and surge-swept rocky or coral areas; often in very shallow water over algal turf and rubble.
Bait notes
Not a common targeted game fish; when taken as food it may be caught incidentally on very small pieces of shrimp, clam, or algae on light tackle. Small flies or tiny soft plastics can provoke curiosity, but it rarely strikes typical sport baits.
Behavior
Primarily a daytime grazer that moves in schools and picks filamentous algae and detritus from hard substrates. It is alert, fast-moving, and uses its caudal spine defensively when crowded or handled.
Caution
Sharp caudal scalpel can cut hands; avoid grabbing near the tail. Like many reef-associated fishes, local consumption advisories may apply in some islands due to ciguatera risk, so check local guidance before eating.
Fishing notes
Best approached with stealth in shallow clear water; use ultra-light gear and small hooks if targeting for observation or incidental catch. Fish around reef flats and surge zones at low tide, but handle carefully and release promptly.