---
title: Brown Coral Blenny (Atrosalarias fuscus)
scientific_name: Atrosalarias fuscus
common_name: Brown Coral Blenny
taxon: Combtooth blenny
conservation_status: LC - Least Concern
published: 2024-11-18T11:59:16.435Z
updated: 2026-08-18T08:09:24.833Z
tags: Brown Coral Blenny, Atrosalarias fuscus, Combtooth blenny, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/combtooth-blenny/brown-coral-blenny
---

# Brown Coral Blenny (*Atrosalarias fuscus*)

## Quick facts

- **Group:** Combtooth blenny (*Blenniidae*)
- **Size:** 14.5 cm
- **Depth:** 2-14 m
- **Diet:** Herbivore
- **Activity:** Diurnal
- **Rarity:** Uncommon
- **Habitat:** Inside branching coral heads on sheltered reef
- **Reproduction:** Egg layer
- **Conservation status:** LC - Least Concern

## How to recognise it

- stout dark brown to almost black body
- juveniles bright yellow, turning dark as they grow
- always among the branches of a coral head, rarely in the open
- up to 14.5 cm

A yellow juvenile and a near-black adult, and everything in between, all inside the same coral head.

This blenny picks a branching coral colony and stays in it. It grazes algae off the dead bases and the surrounding rock, retreats into the branches at any disturbance, and can spend its entire adult life within a couple of meters of where it settled. At fourteen centimeters it is large for a blenny, and a big dark one wedged deep among branches is easy to miss entirely: what you see is a shadow between coral fingers that turns out to have an eye.

The color change with age is real and confuses people. Juveniles are a clean bright yellow, conspicuous against the coral, and as the fish grows the yellow is replaced from the head backward by dark brown until the adult is almost black. Nobody has established what the yellow is for; the usual suggestion is that a small conspicuous fish inside a coral head is advertising that it is not worth chasing into the branches.

It is a fish of sheltered reef in the top dozen meters, and it goes with the coral: no branching colonies, no coral blennies.

## Also known as

- **English:** Black Blenny, Brown Coral Blenny, dusky blenny
- **French:** Blennie coraline d'Érythrée
- **Portuguese:** Blênio-arisco
- **Czech:** slizoun tmavý
- **Russian:** Тёмная атросалария

## Scientific synonyms

- *Astrosalarias fuscus*
- *Astrosalarias fuscus fuscus* (Rüppell, 1838)
- *Atrisalarias fuseus* (Rüppell, 1838)
- *Atrosalarias fuscus fuscus* (Rüppell, 1838)
- *Atrosalarius fuscus*
- *Salarias fuscus* Rüppell, 1838

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/combtooth-blenny/brown-coral-blenny)*
*Updated: August 18, 2026*