Dusky Surgeonfish
Acanthurus nigrofuscus
Dusky Surgeonfish (Acanthurus nigrofuscus) is a small reef-dwelling surgeonfish of tropical Indo-Pacific and adjacent waters, now recorded widely in the Red Sea and many oceanic islands. It grazes on algae over shallow coral and rocky reefs and carries a sharp tail spine; it is not a common target fish.

Identification points
- Small oval surgeonfish with a dusky brown to gray body and darker head
- One or more pale bluish lines/markings on the face and body with a subtly mottled look
- Scalpel-like white spine on each side of the tail base, typical of surgeonfishes
Habitat
Shallow coral and rocky reefs, reef flats, lagoon patch reefs, surge zones, and outer reef slopes with abundant turf algae, typically in warm tropical marine water from very shallow edges to around 30 m.
Bait notes
Not a typical bait species and rarely targeted. If fishing for one, small algae-based baits, bread bits, or tiny pieces of shrimp on light hooks may elicit a take, but small green or brown micro-jigs and unbaited algae-looking offerings are more realistic.
Behavior
Primarily diurnal herbivore/detritivore that scrapes and picks filamentous algae from hard substrate. Often occurs singly or in loose groups and stays close to cover; adults can be territorial around feeding areas.
Caution
The caudal spine is sharp and can cut or puncture hands; use care when netting or unhooking. As a reef-associated tropical fish, consumption is generally uncommon and may carry local reef-fish ciguatera risk in some areas.
Fishing notes
Use very light tackle, tiny hooks, and a subtle presentation near reef edges and tide-swept flats where it feeds. Sight-fishing with a drifted bait or small lure works better than casting distance; handle gently and release quickly if caught.