TankBud

Cobalt blue goby

Stiphodon semoni

Also known as Blue Cobalt Goby, Cobalt blue dwarf goby

FreshwaterFish

Cobalt blue goby (Stiphodon semoni)
The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature
68–79°F
20–26°C
pH
6.5–7.5
Adult size
1.8 in
4.5 cm
Minimum tank
13 gal
50 L
Temperament
Mostly peaceful
Social behavior
Social
Swim level
Bottom
Diet
Omnivore
Difficulty
Difficult
Breeding
No record
Rarity
Rare
Family
Gobiidae
Origin
Sumatra, New Guinea

Overview

The cobalt blue goby is a small bottom-dwelling grazer for a mature stream tank with strong flow. It is a tricky fish, best left to experienced keepers.

Did you know

In the wild the cobalt blue goby climbs waterfalls and fights its way up rushing streams, gripping wet rock as it goes. That climbing ability is how it reaches the upstream habitats where it lives.

Caring for the cobalt blue goby

Give cobalt blue gobies at least 13 gal (50 L) in a mature, algae-rich tank, not a new setup. Copy the fast streams they come from with strong water movement and high oxygen. Add lots of smooth rock and wood covered in algae and biofilm for grazing. Clean, cool to moderate water suits it best, at 68 to 79°F (20 to 26°C) and a pH of 6.5 to 7.5.

Cobalt blue gobies are bottom grazers that spend the day rasping biofilm and algae off surfaces. They will struggle without enough natural growth. Supplement it with algae wafers and small frozen foods like daphnia.

Keep them in mostly peaceful company, though males can squabble over grazing spots. Males carry the bright cobalt color the species is named for.

Good to know

Stiphodon semoni is a small member of the family Gobiidae. Like many of its relatives, it has fused pelvic fins that form a suction disc. The disc lets it hold tight to rock in heavy current.

In the wild

The cobalt blue goby lives in fast, clear, well-oxygenated streams in Sumatra and New Guinea. It clings to rock in the current.

Weekly picks

Tank mates

The cobalt blue goby is a mostly peaceful, social species that keeps to the bottom. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a cobalt blue goby need?

A cobalt blue goby needs at least 13 gal (50 L). It spends most of its time in the bottom.

What temperature and pH does a cobalt blue goby need?

A cobalt blue goby is comfortable at 68–79°F (20–26°C) with a pH of 6.5–7.5.

What does a cobalt blue goby eat?

A cobalt blue goby grazes biofilm and algae off surfaces in a mature tank. Supplement that natural growth with algae wafers and small frozen foods like daphnia.

How big does a cobalt blue goby get?

An adult cobalt blue goby reaches about 1.8 in (4.5 cm).

How can you tell a male cobalt blue goby from a female?

Males carry the bright cobalt color that gives the species its name.

Related species