Neon rainbowfish

Melanotaenia praecox

Also known as Neon Dwarf Rainbow, Dwarf neon praecox rainbowfish

FreshwaterFish

Neon rainbowfish (Melanotaenia praecox) — Imperial Tropicals · Used with permission

Care at a glance

Temperature: 73–82°F; 23–28°C
pH: 6.5–7.5
Adult size: 3.1 in; 8 cm
Minimum tank: 20 gal; 76 L

Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Medium
Breeding: Egg depositor · Hard
Rarity: Rare
Family: Melanotaeniidae
Origin: New Guinea

Overview

The neon rainbowfish is a small, peaceful schooling fish for the middle of a planted community tank. It is best with a little experience.

Did you know

The neon rainbowfish's species name, praecox, means early. It nods to how young and small this fish matures and begins to spawn, compared with its larger relatives.

Caring for the neon rainbowfish

Neon rainbowfish do best in a group of six or more, in a tank of 20 gal (76 L) or larger. Plant the sides well and leave open water for them to cruise. A fine substrate and some driftwood suit them.

Keep the water clean and gently moving, at 73 to 82°F (23 to 28°C) and a pH of 6.5 to 7.5. Feed varied meals of fine flake or small pellet, with frozen bloodworms, daphnia and brine shrimp. Their glow builds with a settled group and good food.

Neon rainbowfish are peaceful and make easy companions for other calm community fish of similar size. Males show the brightest blue body and red fins, while females have yellowish fins and a plainer body.

They spawn continuously, laying a few eggs a day onto fine plants and mops over weeks without tending them. The tiny fry need small first foods and patient care, so breeding them is hard.

Good to know

Melanotaenia praecox belongs to the family Melanotaeniidae and is a true dwarf among rainbowfish. Its blue and red coloring is what many keepers picture when they think of a dwarf rainbowfish. It is also called the neon dwarf rainbow.

In the wild

The neon rainbowfish comes from the Mamberamo River basin, in the north of western New Guinea. It lives in clear, flowing streams and tributaries among plants and wood. The water there is warm and runs neutral to slightly acidic.

Weekly picks

Tank mates

The neon 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 neon rainbowfish need?

A neon rainbowfish needs at least 20 gal (76 L). It spends most of its time in the middle.

What temperature and pH does a neon rainbowfish need?

A neon rainbowfish is comfortable at 73–82°F (23–28°C) with a pH of 6.5–7.5.

What does a neon rainbowfish eat?

A neon rainbowfish eats varied meals of fine flake or small pellet. Add frozen bloodworms, daphnia and brine shrimp.

How big does a neon rainbowfish get?

An adult neon rainbowfish reaches about 3.1 in (8 cm).

Does a neon rainbowfish need a group?

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

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

Males have the brightest blue body and red fins. Females have yellowish fins and a plainer body.

How does a neon rainbowfish breed?

Neon rainbowfish lay a few eggs a day onto fine plants and mops over weeks, and they do not tend them. The tiny fry need small first foods and patient care, so breeding them is hard.