TankBud

Red rainbowfish

Glossolepis incisus

Also known as Irian Red Rainbow

FreshwaterFish

Red rainbowfish (Glossolepis incisus)
Hectonichus · CC BY-SA 3.0

Care at a glance

Temperature
72–77°F
22–25°C
pH
7.0–8.5
Adult size
5.5 in
14 cm
Minimum tank
34 gal
130 L
Temperament
Peaceful
Social behavior
Schooling
Swim level
Middle
Difficulty
Easy
Breeding
Egg depositor · Hard
Rarity
Common
Family
Melanotaeniidae
Origin
New Guinea

Overview

The red rainbowfish is a peaceful, active schooling fish for a long community tank. It is easy to keep.

Did you know

Young male red rainbowfish look plain and silvery, and their red only comes in as they mature. That catches buyers off guard at the shop. Their deepest color shows during morning sparring, when rival males face off and briefly turn an almost glowing red.

Caring for the red rainbowfish

Keep red rainbowfish in a group of at least six, in a tank of 34 gal (130 L) or larger. They are active midwater swimmers that need horizontal space more than height. Give them a long open swimming lane, with planting toward the back and sides.

Keep the temperature at 72 to 77°F (22 to 25°C) and the pH at 7.0 to 8.5. Feed a varied diet of quality flake or small pellets. Frozen foods such as brine shrimp and bloodworms bring out the red.

Red rainbowfish are peaceful, and they pair well with other sturdy, similarly sized community fish. A group lets the males display to each other and color up properly, while a lone male often stays dull. Mature males turn a deep brick-red and develop a high-backed body, while females stay silvery and slimmer.

They are egg scatterers that lay sticky eggs among fine plants over a long spawning period. Breeding them is hard.

Good to know

Glossolepis incisus belongs to the family Melanotaeniidae and is one of the larger rainbows in the hobby. Keepers also know it as the Irian red rainbow.

In the wild

Red rainbowfish have a limited natural range in the Sentani system, in Lake Sentani and nearby waters of New Guinea. Lake Sentani is a warm freshwater lake, with plants along the margins and open water out from shore. Its water is neutral to alkaline and clear.

Weekly picks

Tank mates

The red rainbowfish 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 red rainbowfish need?

A red rainbowfish needs at least 34 gal (130 L). It spends most of its time in the middle.

What temperature and pH does a red rainbowfish need?

A red rainbowfish is comfortable at 72–77°F (22–25°C) with a pH of 7.0–8.5.

What does a red rainbowfish eat?

A red rainbowfish eats a varied diet of quality flake or small pellets. Frozen foods such as brine shrimp and bloodworms bring out its red.

How big does a red rainbowfish get?

An adult red rainbowfish reaches about 5.5 in (14 cm).

Does a red rainbowfish need a group?

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

How can you tell a male red rainbowfish from a female?

Mature males turn a deep brick-red and develop a high-backed body. Females stay silvery and slimmer.

How does a red rainbowfish breed?

Red rainbowfish lay sticky eggs among fine plants over a long spawning period. Breeding them is hard.

Related species