---
title: Plain Rockskipper (Istiblennius unicolor)
scientific_name: Istiblennius unicolor
common_name: Plain Rockskipper
taxon: Combtooth blenny
conservation_status: LC - Least Concern
published: 2024-11-19T12:14:47.462Z
updated: 2026-08-14T11:36:01.899Z
tags: Plain Rockskipper, Istiblennius unicolor, Combtooth blenny, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/combtooth-blenny/plain-rockskipper
---

# Plain Rockskipper (*Istiblennius unicolor*)

## Quick facts

- **Group:** Combtooth blenny (*Blenniidae*)
- **Size:** up to 14 cm
- **Depth:** 0-8 m
- **Diet:** Herbivore
- **Activity:** Diurnal
- **Rarity:** Common
- **Habitat:** Shallow reef flats, rubble and rock with algal turf
- **Reproduction:** Egg layer, Gonochoric
- **Endemic:** Endemic to the Red Sea
- **Conservation status:** LC - Least Concern

## How to recognise it

- stout blenny with a blunt vertical face and high-set eyes
- mottled gray-brown with darker bars, branched tentacles over the eyes
- perches on rock propped on its pelvic fins
- length up to 14 cm

A stout blunt-faced blenny perched on a rock in the shallows, propped up on its pelvic fins like a small gargoyle, with branched tentacles over each eye.

It is a lawnmower. The mouth is set underneath the head and filled with rows of fine comb-like teeth - not for biting but for scraping, dragged across rock to strip the algal film off it. A grazing blenny works in a series of quick downward pecks, and a rock it has cleaned shows the marks.

The eyes move independently and sit high enough to watch the whole hemisphere above the fish, which is what an animal that cannot swim fast needs. Escape is not speed, it is being one hop from a hole.

Fourteen centimeters (5.5 in). Common on any shallow flat, and one of the few reef fish a snorkeler can watch for ten minutes without it going anywhere.

## Also known as

- **English:** Pallid Rockskipper, olive blenny

## Scientific synonyms

- *Halmablennius unicolor* (Rüppell, 1838)
- *Salarias unicolor* Rüppell, 1838

## Range

Eritrea, Mozambique

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/combtooth-blenny/plain-rockskipper)*
*Updated: August 14, 2026*