TankBud

Pygmy rainbowfish

Melanotaenia pygmaea

Also known as Prince Regent rainbowfish

FreshwaterFish

Pygmy rainbowfish (Melanotaenia pygmaea)
Andrewbogott · CC BY-SA 4.0

Care at a glance

Temperature
73–84°F
23–29°C
pH
6.5–7.8
Adult size
2.4 in
6 cm
Minimum tank
20 gal
75 L
Temperament
Peaceful
Social behavior
Schooling
Swim level
Middle
Difficulty
Medium
Breeding
Egg scatterer · Medium
Rarity
Rare
Family
Melanotaeniidae
Origin
Prince Regent River, Kimberley, Western Australia

Overview

The pygmy rainbowfish is a true small-tank rainbowfish, a peaceful schooler for a planted aquarium. It needs a little more experience than the easiest community fish.

Did you know

The pygmy rainbowfish's home on the Prince Regent River is so remote that the area remains roadless wilderness. It lies within a protected reserve, reached mainly by boat or aircraft.

Caring for the pygmy rainbowfish

Keep pygmy rainbowfish in a school of eight or more, in a tank of 20 gal (75 L) or larger. A group of ten fits comfortably in that size and makes a complete little display. Give them plants, driftwood and open swimming lanes, all scaled to their small size.

They like soft to moderately hard water around neutral, at a pH of 6.5 to 7.8. Hold the temperature at 73 to 84°F (23 to 29°C). Bright morning light brings out the blue. Offer fine foods such as crushed flake and small granules, plus frozen or live daphnia, cyclops and baby brine shrimp.

Pygmy rainbowfish are peaceful and best kept with gentle, small tank mates rather than larger or boisterous fish. Breeding them is of medium difficulty. They scatter adhesive eggs among fine plants or mops, and the very small fry need patient rearing on tiny foods.

Good to know

Melanotaenia pygmaea is a member of the family Melanotaeniidae, described by Gerald Allen in 1978. It is the smallest species in its genus. It is silvery blue, with a dark, brightly edged band along the side. Some keepers call it the Prince Regent rainbowfish.

In the wild

The pygmy rainbowfish lives in the Prince Regent River and nearby streams, in the remote gorge country of the Kimberley in Western Australia.

Weekly picks

Tank mates

The pygmy 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 pygmy rainbowfish need?

A pygmy rainbowfish needs at least 20 gal (75 L). It spends most of its time in the middle.

What temperature and pH does a pygmy rainbowfish need?

A pygmy rainbowfish is comfortable at 73–84°F (23–29°C) with a pH of 6.5–7.8.

What does a pygmy rainbowfish eat?

A pygmy rainbowfish eats fine foods such as crushed flake and small granules. It also takes frozen or live daphnia, cyclops and baby brine shrimp.

How big does a pygmy rainbowfish get?

An adult pygmy rainbowfish reaches about 2.4 in (6 cm).

Does a pygmy rainbowfish need a group?

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

How does a pygmy rainbowfish breed?

Pygmy rainbowfish scatter adhesive eggs among fine plants or mops. The very small fry need patient rearing on tiny foods, and breeding is of medium difficulty.

Related species