Colours

Distinguishing features

A medium sized, dark brown fish with yellowish dorsal and anal fins, which appears almost black underwater when viewed from a distance. The crescent shaped tail and the white tail ring are distinctive. Distinguish from other Acanthurus species by the white caudal knives, the blue tail with spots, the irregular yellow blotch behind and adjacent to the eye, and the yellow stripe in front of the eye.

Size

Depth range

Synonyms

Distribution

Distribution and habitat preferences

Areas of turf algae and coral rubble on reef flats and slopes.

Found in most reef habitats around the island, although most abundant on exposed reef fronts and nearby flats.

Behaviour

The Pencil surgeonfish is a roving herbivore, moving around the reef in schools and feeding on the fine turf algae. The surgeonfish are a very long lived group of fishes - after settlement to the reef, juveniles grow quickly and reach 80% of their maximum size in about 3 years, and then grow very slowly thereafter. Many of them live from 30-50years. They spawn in groups during the warmer months, when fast running tidal currents coincide with dawn and dusk.

Web resources

Danger

References