TankBud

Twinspot goby

Signigobius biocellatus

Also known as Signal Goby, Two-Spot Goby, Crabeye Goby, Four-Wheel Drive Goby

SaltwaterFish

Twinspot goby (Signigobius biocellatus)
Chika Watanabe from Los Altos, USA · CC BY 2.0

Care at a glance

Temperature
73–81°F
23–27°C
pH
8.1–8.4
Adult size
3.9 in
10 cm
Minimum tank
30 gal
115 L
Temperament
Peaceful
Social behavior
Social
Tankmates
With caution
Swim level
Bottom
Difficulty
Difficult
Breeding
Hard
Rarity
Common
Reef safe
Reef safe
Family
Gobiidae
Origin
Found in the western Pacific from Indonesia and the Philippines to Papua New Guinea and northern Australia, on silty sand near coastal reefs.

Overview

This is a difficult fish that needs a mature 115 litre or larger tank with a deep fine sand bed and a strong population of tiny sand life, ideally fed by a refugium. Keep it at 23 to 27 C and pH 8.1 to 8.4. It is reef safe but spits sand, so keep corals off the bottom. Offer live and enriched frozen brine, mysis, and black worms often, as many specimens slowly starve in tanks that cannot supply enough small prey.

In the wild

The twinspot goby lives in monogamous pairs on open silty sand near coastal reefs. It feeds by scooping mouthfuls of sand, filtering out tiny animals, and letting the sand fall from its gills. Two large eyespots on the dorsal fins make its back end look like the face of a larger animal. It builds and hides in burrows under rocks.

Good to know

Signigobius biocellatus is the only species in its genus, in the goby family Gobiidae. The paired eyespots are thought to bluff predators by mimicking the face of a crab or larger fish. Pairs may fan their fins in a jerky display that looks like a small crab scuttling over the sand.

Did you know

The bold spots on its back give the fish its other common name, the four-wheel drive goby, from the way a pair trundles across the sand together.

Common questions

What size tank does a Twinspot goby need?

A Twinspot goby needs at least 30 gal (115 L). It spends most of its time in the bottom.

What temperature and pH does a Twinspot goby need?

A Twinspot goby is comfortable at 73–81°F (23–27°C) with a pH of 8.1–8.4.

How big does a Twinspot goby get?

An adult Twinspot goby reaches about 3.9 in (10 cm).

Related species