---
title: Dusky Frillgoby (Bathygobius fuscus)
scientific_name: Bathygobius fuscus
common_name: Dusky Frillgoby
taxon: Gobies
conservation_status: LC - Least Concern
published: 2024-11-20T19:22:57.585Z
updated: 2026-08-17T15:46:05.977Z
tags: Dusky Frillgoby, Bathygobius fuscus, Gobies, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/gobies/dusky-frillgoby
---

# Dusky Frillgoby (*Bathygobius fuscus*)

## Quick facts

- **Group:** Gobies (*Gobiidae*)
- **Size:** 12 cm
- **Depth:** 1-6 m
- **Diet:** Omnivore
- **Activity:** Diurnal
- **Rarity:** Common
- **Habitat:** Tide pools, rocky intertidal, rubble and shallow reef
- **Reproduction:** Egg layer
- **Conservation status:** LC - Least Concern

## How to recognise it

- pale yellow-brown with large irregular dark blotches
- rows of small pale blue spots, one to a scale
- yellow outer edge to the dorsal and tail fins
- in tide pools and the shallowest rocky ground, often out of the water's reach at low tide
- up to 12 cm

This fish can jump from one tide pool to the next without being able to see where it is going, and it does not do it by luck.

The experiments that showed how are old and famous. A frillfin goby trapped in a pool at low tide will leap accurately into the neighboring pool, one it cannot see from the water it is in. Take a fish that has never been over that stretch of rock and it will not jump at all. The animal learns the layout at high tide, when the whole shelf is submerged and it can swim over the pools and register where the depressions are, and it keeps that map for weeks. At low tide it jumps from memory.

That is a decent piece of spatial learning for a twelve-centimeter fish, and it exists because the intertidal is brutal: a pool can overheat, go salty, or run out of oxygen in an afternoon, and the fish that can leave has an option the fish that cannot does not.

It lives in exactly that band, in tide pools and shallow rocky ground, and it eats close to everything: detritus, crustaceans, algae, small fish.

## Also known as

- **English:** dusky frill-goby, Brown Frillfin, dusky frillfin goby
- **Arabic:** قوبيون مهدب قاتم, قوبيون بني, قوبيون شائع
- **French:** Gobie moucheté
- **Portuguese:** Góbio-de-estuário-do-Mar-Vermelho
- **Japanese:** クモハゼ, Kumohaze
- **Chinese:** 深鰕虎, 深鰕虎魚, 褐深鰕虎
- **KO:** 무늬망둑
- **MAH:** Jibalan
- **MAL:** Mannunni, മന്നുണ്ണി

## Scientific synonyms

- *Bathygobius fuscus fuscus* Ruppell, 1830
- *Bathygobius samberanoensis* (Bleeker, 1867)
- *Bathygobius sambiranoensis* (Bleeker, 1867)
- *Bathygobius vergeri* (Bleeker, 1867)
- *Gobius darnleyensis* Alleyne & MacLeay, 1877
- *Gobius fuscus* Rüppell, 1830
- *Gobius fuscus fuscus* Rüppell, 1830
- *Gobius marginalis* De Vis, 1884
- *Gobius nebulopunctatus* Valenciennes, 1837
- *Gobius nigripinnis* Alleyne & MacLeay, 1877
- *Gobius obscurus* Peters, 1855
- *Gobius punctillatus* Rüppell, 1830
- *Gobius samberanensis* Bleeker, 1867
- *Gobius samberanoensis* Bleeker, 1867
- *Gobius sambiranoensis* Bleeker, 1867
- *Gobius vergeri* Bleeker, 1867
- *Stenogobius vergeri* (Bleeker, 1867)

## Range

Comoros, Indian Ocean, Kenya, Madagascar, Mozambique, Red Sea, Republic of Mauritius, Seychelles

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/gobies/dusky-frillgoby)*
*Updated: August 17, 2026*