Goldie River Rainbowfish

Melanotaenia goldiei

Rainbowfish
Reviewed by Guidarium Editorial DeskUpdated May 6, 2026

The Goldie River Rainbowfish is a vibrant, highly active schooling fish native to the clear rainforest streams and backwaters of southern New Guinea. As rapid swimmers, they require significant open swimming space. They are voracious mid-water and surface feeders that will readily eat insects and standard aquarium foods. While peaceful, their exuberant energy can intimidate shy tank mates.

Goldie River Rainbowfish At a Glance

Adult Size11.5 cm
Body ShapeFusiform
Growth RateModerate
TemperamentPeaceful
Water TypeFreshwater Only
Flow PreferenceModerate
Waste OutputLow
StockingGroup of 5+

Goldie River Rainbowfish Tank Requirements

Minimum Volume130 L
Minimum Length90 cm
FlowModerate
Water TypeFreshwater Only
Must-Haves in the Tank
Plants - Densely covered
Stocking calculator

Will Goldie River Rainbowfish fit in your tank?

Care guides tell you what Goldie River Rainbowfish needs, the next question is whether your tank can safely provide it. Test Goldie River Rainbowfish against your tank size, maintenance needs, and the fish you already keep before you buy.

Goldie River Rainbowfish
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Goldie River Rainbowfish Water Parameters

Temperature2428°C
pH78
Hardness816 dGH

Goldie River Rainbowfish Temperament & Compatibility

Aggression LevelPeaceful
2/10
Where They Swim
Surface
Mid-level
Bottom
Stocking Guidelines
Keep at Least5 fish
Max per TankNo limit
Can Live Alone?No — needs a group
Behavior Traits
Hyperactive / Fast SwimmerJumper (Lid Required)Aggressive Eater (Starves shy fish)Fry Predator

Goldie River Rainbowfish Varieties

Each variety inherits the species defaults above. Only differences are highlighted.

Male

Males develop a pronounced arched back (deep-bodied) as they mature, displaying vibrant coppery-brown hues, darker mid-lateral stripes, and longer, pointed dorsal and anal fins. Males actively and persistently court females.

Differs in 1 trait from base species

Also known as: Show Male, Standard

Behavior Traits
Hyperactive / Fast SwimmerJumper (Lid Required)Aggressive Eater (Starves shy fish)Fry PredatorAggressive to same species/look-alikes

Female

Females are slightly smaller, possess a more streamlined body shape, and display more subdued, silvery-coppery coloration with rounded fins. It is highly recommended to keep more females than males to disperse breeding harassment.

Differs in 1 trait from base species

Also known as: Unsexed Juvenile

Adult Size10 cm

Goldie River Rainbowfish Care Guide Summary

The Goldie River Rainbowfish, scientifically known as Melanotaenia goldiei, belongs to the Rainbowfish family group. Adults reach a maximum size of approximately 11.5 cm and have a fusiform body shape with a moderate growth rate. Classified as peaceful, this species primarily occupies the surface and mid-level zones of the aquarium and produces a low level of biological waste.

To thrive, the Goldie River Rainbowfish requires a freshwater only aquarium with a minimum volume of 130 litres and a tank length of at least 90 cm. Water temperature should be maintained between 24°C and 28°C, with a pH range of 78 and a general hardness of 816 dGH. A moderate water flow is preferred.

The Goldie River Rainbowfish is a rewarding species to keep, provided its core environmental needs are met. This species is available in 2 varieties: Male and Female. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.

Goldie River Rainbowfish Habitat Setup

When setting up an aquarium for the Goldie River Rainbowfish, a moderate water flow best suits their natural preferences. Because this species occupies the surface and mid-level zones, the aquarium layout should prioritise adequate surface area with floating cover to make them feel secure near the waterline and open swimming space in the centre of the tank for free movement. Useful additions include dense planting to provide cover, break sightlines, and reduce stress. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.

Goldie River Rainbowfish Compatibility Notes

Classified as peaceful, the Goldie River Rainbowfish is a social species that requires the company of its own kind to thrive. When choosing tankmates, shy or slow-feeding tankmates may be outcompeted at feeding time and their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the surface and mid-level zones can help reduce competition and territorial overlap.

Who Goldie River Rainbowfish Is Actually For

Goldie River Rainbowfish is best for a fishkeeper who wants a species that can settle into a calmer community setup and can provide a keeper who can commit to a proper group of at least 5. It makes the most sense for a hobbyist who will actually build around its needs, especially plants.

The most common mistake is buying Goldie River Rainbowfish for looks first and only later discovering how its adult size, behavior, or bioload changes the whole tank plan. Another frequent problem is underestimating its social needs. A token pair or trio often behaves very differently from a real group.

Goldie River Rainbowfish Recommended Tank Sizes

Standard aquarium sizes that meet the minimum volume and length requirements for Goldie River Rainbowfish.

Show 9 more tank sizes

Goldie River Rainbowfish Feeding & Diet Considerations

The Goldie River Rainbowfish will eat fry, so breeding efforts in the same tank are unlikely to succeed and is an aggressive eater that may prevent timid tankmates from getting enough food, so target feeding or simultaneous feeding at opposite ends of the tank can help.

Frequently Asked Questions About Goldie River Rainbowfish

How big does Goldie River Rainbowfish get?

Goldie River Rainbowfish (Melanotaenia goldiei) typically reaches a maximum adult size of approximately 11.5 cm. They have a fusiform body shape and a moderate growth rate.

What tank size does Goldie River Rainbowfish need?

A minimum aquarium volume of 130 litres and a tank length of at least 90 cm are recommended for Goldie River Rainbowfish. This ensures enough swimming space and helps maintain stable water conditions.

What water parameters does Goldie River Rainbowfish need?

Goldie River Rainbowfish thrives in freshwater only conditions with a temperature range of 24–28°C, a pH between 7 and 8, and a general hardness of 8–16 dGH. A moderate water flow is preferred.

Is Goldie River Rainbowfish peaceful or aggressive?

Goldie River Rainbowfish is classified as peaceful with an aggression score of 2 out of 10. They are generally well-suited to peaceful community tanks.

Can Goldie River Rainbowfish live alone?

No, Goldie River Rainbowfish should be kept in groups of at least 5 to reduce stress and encourage natural behaviour.

Does Goldie River Rainbowfish have any special tank requirements?

Yes. Goldie River Rainbowfish benefits from plants - densely covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.

Does Goldie River Rainbowfish need a lid on the tank?

Yes. Goldie River Rainbowfish is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 6, 2026
Last updated
May 6, 2026
Issues or corrections?
Contact the editorial team

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