Indo-Pacific region, including the Hawaiian Islands and the Great Barrier Reef
Conservation status
Least Concern
Edibility
Edible and eaten locally in parts of its range, but reef surgeonfish can carry ciguatera toxins. Avoid consumption where ciguatera is known or suspected, and follow public-health advisories.
Culinary quality / 5
2
Danger level
Caution
Usual observation depth
1–30 m
Behaviour
Observed alone, in pairs or in small loose groups while grazing. Active during the day, it often patrols a small feeding area and may form larger aggregations during breeding.
Observation zones
Shallow reef, reef flat, lagoon, rocky reef, and hard-bottom areas covered with algae.
Diet
Primarily filamentous turf algae and other benthic algae, supplemented by detritus and associated microorganisms grazed from hard surfaces.
Reproduction
Oviparous
Identification marks
Oval and laterally compressed surgeonfish, grayish-brown, bearing numerous fine longitudinal pale blue to bluish-gray lines, especially visible on the head and flanks. A pale blue ring surrounds the eye, and a sharp retractable spine is present on each side of the caudal peduncle.
Similar species
It can be confused with other brown surgeonfish of the genus Acanthurus. The numerous fine bluish longitudinal lines and the pale blue ring around the eye help identify it. It is clearly distinguishable from the convict surgeonfish (Acanthurus triostegus), with broad dark vertical bars, and the lined surgeonfish (Acanthurus lineatus), with much more contrasting stripes.
Approach rules
Approach slowly and calmly without blocking its grazing path; keep at least 2 m away whenever possible. Do not touch or corner it: the caudal spines can cause cuts. Avoid repeated direct flashes and never feed wildlife.
Protection
Classified as « Least Concern » on the IUCN Red List. It is not listed under CITES. General protection should prioritize the conservation of reef habitats and avoid unnecessary collection or disturbance.
