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
Swim level: Bottom
Difficulty: Difficult
Breeding: Hard
Rarity: Common
Reef safe: Reef safe
Origin: Found in the western Pacific from Indonesia and the Philippines to Papua New Guinea and northern Australia, on silty sand near coastal reefs.
Family: Gobiidae

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.