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
Difficulty
Difficult
Breeding
No record
Rarity
Rare
Family
Gobiidae
Origin
Sumatra, New Guinea

Overview

This is a tricky fish that depends on a mature, algae-rich tank, so it is not one for a new setup. It is a bottom grazer that spends its day rasping biofilm and algae off surfaces, and it will struggle if there is not enough natural growth, so supplement with algae wafers and small frozen foods like daphnia. Keep it in mostly peaceful company, though males can squabble over grazing spots. Give it at least 50 liters with strong flow and clean water at pH 6.5 to 7.5.

In the wild

The cobalt blue goby lives in fast, clear, well-oxygenated streams in Sumatra and New Guinea, clinging to rock in the current. To keep it well you need to copy that flow, so run a tank with strong water movement, high oxygen, and lots of smooth rock and wood covered in algae and biofilm for grazing. Cool to moderate water, around 20 to 26 C, suits it best.

Good to know

Stiphodon semoni is in the family Gobiidae and stays small, around 4.5 cm. Males carry the bright cobalt color the species is named for. Like many of its relatives it has fused pelvic fins that form a suction disc, letting it hold tight to rock in heavy current.

Did you know

In the wild this goby climbs waterfalls and fights its way up rushing streams using its sucker-like pelvic disc to grip wet rock. That climbing ability is how it reaches the upstream habitats where it lives.

Weekly picks

Tank mates

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.

How big does a Cobalt blue goby get?

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

Related species