---
title: Dusky Gregory (Stegastes nigricans)
scientific_name: Stegastes nigricans
common_name: Dusky Gregory
taxon: Pomacentridae
conservation_status: LC - Least Concern
published: 2024-11-14T14:55:30.160Z
updated: 2026-08-15T13:54:13.608Z
tags: Dusky Gregory, Stegastes nigricans, Pomacentridae, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/pomacentridae/dusky-gregory
---

# Dusky Gregory (*Stegastes nigricans*)

## Quick facts

- **Group:** Pomacentridae (*Pomacentridae*)
- **Size:** up to 14 cm
- **Depth:** 1-12 m
- **Diet:** Herbivore
- **Activity:** Diurnal
- **Rarity:** Common
- **Habitat:** Shallow reef flats and dead coral, in defended territories
- **Reproduction:** Egg layer, Gonochoric
- **Hazard:** Dangerous
- **Conservation status:** LC - Least Concern

## How to recognise it

- dusky brown-gray body, darker toward the tail, with a pale-edged dark spot at the rear of the dorsal fin
- always over a patch of long algal turf that stands out from the reef around it
- attacks anything entering the patch, including divers
- length up to 14 cm

A drab brown fish that runs a farm and will fight a diver over it.

The patch of long, untidy algal turf on a reef flat is not neglect - it is cultivated. This damselfish weeds it: it bites out the algal species it does not want and spits them over the boundary, and what is left is a near-monoculture of one or two soft red algae that grow nowhere else on the reef because nothing else lets them. Remove the fish and the crop is grazed away within days by everything that has been waiting.

Defending it is a full-time job. The fish drives off parrotfish and surgeonfish many times its size, chases urchins out, and will charge and bite a diver who kneels in the wrong place. Fourteen centimeters (5.5 in) of very serious intent.

The farms also shelter other animals - small shrimps, gobies and worms live inside them under the fish's protection, which makes each one a little island of a different community on the reef. It is one of the clearest cases of an animal engineering its own habitat.

## Also known as

- **English:** black damselfish, Dusky Gregory, dusky farmerfish
- **French:** Poisson-fermier à tache noire, Grégoire Noir, Négrillon
- **Italian:** Damigella scura
- **German:** Schwarzer Georg
- **Spanish:** Chopita negra
- **Portuguese:** Donzela-escura
- **Czech:** sapín bojovný
- **Japanese:** クロソラスズメダイ, Kurosorasuzumedai
- **Chinese:** 厚殼仔, 黑眶鋸雀鯛, 黑眶锯雀鲷
- **CA:** Damisel·la de Lacépède
- **TAH:** 'atoti

## Scientific synonyms

- *Abudefduf tamaii* Aoyagi, 1941
- *Abudefduf tsamaii* Aoyagi, 1941
- *Eupomacentrus nigricans* (Lacepède, 1802)
- *Holocentrus nigricans* Lacepède, 1802
- *Parapomacentrus nigricans* (Lacepède, 1802)
- *Pomacentrus nigricans* (Lacepède, 1802)
- *Pomacentrus scolopseus* Quoy & Gaimard, 1825
- *Pomacentrus scolopsis* Günther, 1862
- *Pomacentrus subniger* De Vis, 1885
- *Pomacentrus taeniops* Cuvier, 1830
- *Segastes nigricans* (Lacepède, 1802)

## Range

Comoros, Djibouti, Eritrea, Federal Republic of Somalia, Indian Ocean, Kenya, Madagascar, Mozambique, Red Sea, Republic of Mauritius, Seychelles

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/pomacentridae/dusky-gregory)*
*Updated: August 15, 2026*