---
title: Red Sea Surgeonfish (Acanthurus gahhm)
scientific_name: Acanthurus gahhm
common_name: Red Sea Surgeonfish
taxon: Surgeonfishes
conservation_status: LC - Least Concern
published: 2024-11-01T10:25:10.934Z
updated: 2026-08-17T17:16:58.577Z
tags: Red Sea Surgeonfish, Acanthurus gahhm, Surgeonfishes, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/surgeonfishes/red-sea-surgeonfish
---

# Red Sea Surgeonfish (*Acanthurus gahhm*)

## Quick facts

- **Group:** Surgeonfishes (*Acanthuridae*)
- **Size:** 50 cm
- **Depth:** 1-40 m
- **Diet:** Omnivore
- **Activity:** Diurnal
- **Rarity:** Common
- **Habitat:** Reef, lagoons and adjacent sand
- **Reproduction:** Broadcast spawner
- **Hazard:** Dangerous
- **Endemic:** Endemic to the Red Sea
- **Conservation status:** LC - Least Concern

## How to recognise it

- black to very dark brown body with a white ring around the tail base
- yellow line around the eye and yellow tips to the pectoral fins
- oval flattened body, moving on its pectoral fins rather than its tail
- a fixed blade lying in a groove on each side of the tail base
- up to 50 cm

The name is literal. On each side of the tail base a surgeonfish carries a blade, and this is not a spine that happens to be sharp: it is hinged, it folds down into a groove where it sits flush with the body, and the fish flicks it out sideways and drives it home with a sweep of the tail. The edge is sharp enough to open a diver's hand to the bone, and the injuries that happen are almost all to people who grabbed one.

That is the entire danger. It does not attack anything, it is not venomous in this genus, and the blade exists for arguments with other surgeonfish over grazing ground.

This one is the big black surgeonfish of the Red Sea, half a meter long, and it lives here and in the Gulf of Aden and nowhere else. Reports from further east are almost always a different species being misnamed.

It is a grazer that also takes zooplankton and small animals, it moves with its pectoral fins like the rest of the family, and it works reef, lagoon and sand alike, sometimes alone and sometimes in loose groups.

The name gahhm is not Latin. It is the Arabic name for the fish on this coast, written down by Forsskal and made into a scientific name in 1789.

## Also known as

- **English:** Black Surgeonfish, dusky surgeonfish

## Scientific synonyms

- *Acanthurus gahm* (Forsskål, 1775)
- *Chaetodon nigrofuscus gahhm* Forsskål, 1775

## Range

Federal Republic of Somalia, Mozambique, Seychelles

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/surgeonfishes/red-sea-surgeonfish)*
*Updated: August 17, 2026*