TankBud

Ornate rainbowfish

Rhadinocentrus ornatus

Also known as Soft-spined rainbowfish, Ornate rainbow

FreshwaterFish

Ornate rainbowfish (Rhadinocentrus ornatus)
Dirk Godlinski · CC BY-SA 3.0

Care at a glance

Temperature
64–82°F
18–28°C
pH
5.5–7.0
Adult size
2.4 in
6 cm
Minimum tank
20 gal
75 L
Temperament
Mostly peaceful
Social behavior
Schooling
Swim level
Middle
Difficulty
Medium
Breeding
Medium
Rarity
Rare
Family
Melanotaeniidae
Origin
Native to coastal southeastern Queensland and northern New South Wales, Australia, in tannin-stained wallum streams, tranquil pools and creeks over sandy substrate.

Overview

The ornate rainbowfish is a small schooling rainbowfish for a soft, acidic planted tank. It is a fair choice once you have kept a few easier fish.

Did you know

Different wallum creeks hold their own distinct color strains of ornate rainbowfish. Hobbyists label their fish by location and keep the forms separate to preserve the natural variety.

Caring for the ornate rainbowfish

Keep a group of at least six ornate rainbowfish in a tank of 20 gal (75 L) or larger. A planted tank with driftwood, botanicals for tannins, fine-leaved plants and gentle flow suits them.

Keep the water at 64 to 82°F (18 to 28°C), with a soft, acidic pH of 5.5 to 7.0. Soft water below pH 6.5 keeps them healthiest and most colorful. They benefit from a slight seasonal temperature drop in winter, which mimics their home range.

Feed small flake, micro pellets and frozen foods such as daphnia, cyclops and brine shrimp. Ornate rainbowfish are mostly peaceful but small, so pair them with other calm, similarly sized fish rather than boisterous tank mates. Breeding them is of medium difficulty.

Good to know

Rhadinocentrus ornatus is the only species in its genus and a member of the rainbowfish family Melanotaeniidae. Its other common name, soft-spined rainbowfish, refers to the flexible fin spines that separate it from related genera. Many wild populations are isolated in separate creek systems. These isolated groups have produced color forms from blue and green to red-flushed fish.

In the wild

Ornate rainbowfish are native to coastal southeastern Queensland and northern New South Wales, in Australia. They live in tannin-stained wallum streams, tranquil pools and creeks over sand. The water is soft, acidic and often tea colored, and it runs past dense marginal plants.

Weekly picks

Tank mates

The ornate rainbowfish is a mostly 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 an ornate rainbowfish need?

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

What temperature and pH does an ornate rainbowfish need?

An ornate rainbowfish is comfortable at 64–82°F (18–28°C) with a pH of 5.5–7.0.

What does an ornate rainbowfish eat?

An ornate rainbowfish eats small flake and micro pellets. Add frozen foods such as daphnia, cyclops and brine shrimp.

How big does an ornate rainbowfish get?

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

Does an ornate rainbowfish need a group?

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

Related species