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
Diet
Carnivore
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

The twinspot goby is a peaceful sand sifter for the bottom of a mature saltwater tank. It is a fish for experienced keepers.

Did you know

The twinspot goby's bold spots give it another common name, the four-wheel drive goby. The name comes from the way a pair trundles across the sand together.

Caring for the twinspot goby

Give the twinspot goby a mature tank of 30 gal (115 L) or more with a deep bed of fine sand. The sand needs a strong population of tiny sand life, ideally fed by a refugium. The goby scoops up mouthfuls of sand, filters out the tiny animals and lets the sand fall from its gills.

Keep the water at 73 to 81°F (23 to 27°C) with a pH of 8.1 to 8.4. Offer live and enriched frozen brine shrimp, mysis and black worms, and feed often. Many twinspot gobies slowly starve in tanks that cannot supply enough small prey.

It is peaceful and does fine alone or in a group, but choose its tank mates with caution. It is reef safe, though it spits sand, so keep corals off the bottom. Breeding it is hard.

Good to know

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

In the wild

Twinspot gobies come from the western Pacific, from Indonesia and the Philippines to Papua New Guinea and northern Australia. They live in monogamous pairs on open, silty sand near coastal reefs. Each fish builds burrows under rocks and hides in them.

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.

What does a twinspot goby eat?

A twinspot goby eats live and enriched frozen brine shrimp, mysis and black worms. It also filters tiny animals out of mouthfuls of sand, so it needs a mature sand bed full of small prey.

How big does a twinspot goby get?

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

Related species