TankBud

Unicorn tetra

Erythrocharax altipinnis

FreshwaterFish

Care at a glance

Temperature
75–82°F
24–28°C
pH
5.0–6.8
Adult size
1.3 in
3.3 cm
Minimum tank
14 gal
54 L
Temperament
Peaceful
Social behavior
Schooling
Swim level
Middle
Difficulty
Medium
Breeding
Egg scatterer
Rarity
Rare
Family
Characidae
Origin
Rio Curuá, Serra do Cachimbo, Brazil

Overview

The unicorn tetra is a tiny, peaceful schooling fish for a soft, gently stained planted tank. It looks best in a big group and is a step up from the easiest tetras.

Did you know

The unicorn tetra, from a single plateau river, was different enough that scientists built an entirely new genus around it in 2013. That shows how isolated and distinct the Serra do Cachimbo streams are.

Caring for the unicorn tetra

Keep unicorn tetras in a group of at least ten, in a well planted, calm tank of 14 gal (54 L) or more. Driftwood, leaf litter, a dark substrate and dim light suit them, with the water gently stained.

Give them soft, acidic water with low hardness, at 75 to 82°F (24 to 28°C) and a pH of 5.0 to 6.8. Feed very small foods such as fine flake, crushed micro pellets, cyclops, microworm and baby brine shrimp.

Unicorn tetras are peaceful and swim in the middle of the tank. Keep them only with small, calm companions, such as other nano tetras, pygmy corydoras and small rasboras. Larger fish will eat or outcompete them. The green-eye tetra shares their home stream, so the two make a natural single-river display.

Males extend tall dorsal fin rays, the horn behind the unicorn trade name, and the species name altipinnis refers to them. Unicorn tetras scatter their eggs, but their breeding in the aquarium is not documented.

Good to know

The unicorn tetra is a miniature characin of the family Characidae. Its genus name, Erythrocharax, means red charax, for the bright red adipose and tail fins of living fish.

In the wild

Erythrocharax altipinnis comes from the clear rio Curuá, a tributary of the rio Iriri in the upper Rio Xingu basin. The river drains the Serra do Cachimbo in Pará, Brazil, and its waters are warm, soft and acidic.

Weekly picks

Tank mates

The unicorn tetra is a peaceful, schooling species that keeps to the middle. 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 unicorn tetra need?

A unicorn tetra needs at least 14 gal (54 L). It spends most of its time in the middle.

What temperature and pH does a unicorn tetra need?

A unicorn tetra is comfortable at 75–82°F (24–28°C) with a pH of 5.0–6.8.

What does a unicorn tetra eat?

A unicorn tetra eats very small foods, such as fine flake, crushed micro pellets, cyclops, microworm and baby brine shrimp.

How big does a unicorn tetra get?

An adult unicorn tetra reaches about 1.3 in (3.3 cm).

Does a unicorn tetra need a group?

Yes. A unicorn tetra is a schooling species and should be kept in a group, not singly.

How can you tell a male unicorn tetra from a female?

Males extend tall rays from the dorsal fin, which form the horn behind the unicorn name.

How does a unicorn tetra breed?

Unicorn tetras scatter their eggs. Their breeding in the aquarium has not been documented.

Related species