Surgeonfishes
Doctorfish
Acanthurus chirurgus
Species Overview
Blue-gray to dark brown surgeonfish able to pale or darken; 10-12 thin dark vertical bars on the sides; often a broad pale area at the tail base; caudal spine sheath dark; tail only slightly emarginate.
- Size
- Typically 15-30 cm (6-12 in) per ReefGuide; common length 35 cm TL; maximum recorded 39 cm TL (15 in), weight 5.1 kg (FishBase).
- Habitat
- Shallow rocky or coral reef bottoms; also forages in inshore seagrass beds.
- Diet
- Algae and organic detritus grazed from sand and rock, swallowing sand that helps grind food in a gizzard-like stomach (FishBase; Florida Museum).
- Range
- Caribbean, Bahamas, Florida, Bermuda, Gulf of Mexico and Brazil (ReefGuide); western Atlantic from Massachusetts to Sao Paulo, Brazil, and eastern Atlantic at Senegal and Ascension Island (FishBase).
Life stages
No separate life-stage photos on ReefGuide; juveniles about 5 cm when they settle inshore (Florida Museum). Pale phase over sand, dark phase on reefs.
Ecological role
Herbivorous grazer; prey for large predatory fishes such as tunas.
Explore reef conservation
Learn about Caribbean reef habitats, invasive lionfish and the work of the Caribbean Reef Fish Foundation.
TL means total length; SL excludes the tail fin; FL measures to the tail fork. These measurements are not interchangeable.