MacCulloch’s Rainbowfish

Description

MacCulloch’s Rainbowfish (Melanotaenia maccullochi)

MacCulloch’s Rainbowfish (Melanotaenia maccullochi) is a small, peaceful rainbowfish native to northern Australia. Considerably smaller than many of the better-known Melanotaenia species, they are an excellent choice for aquarists who love the active behaviour and colourful displays of rainbowfish but don’t have room for some of their larger relatives.

Their colouration can vary between populations and strains, but the combination of horizontal body markings, attractive finnage and flashes of colour displayed by mature males makes them particularly attractive when kept as a good-sized shoal.

MacCulloch’s Rainbowfish Set Up

We recommend a well-planted aquarium with plenty of open swimming space. Plants around the back and sides of the aquarium provide security while leaving the centre and upper areas clear for the group to swim and display.

Although relatively small, these are active shoaling fish and aquarium length is important. Good filtration and well-oxygenated water are recommended, although excessive current isn’t necessary.

A secure lid is also advisable. Like many rainbowfish, they are active swimmers and are perfectly capable of jumping from an uncovered aquarium.

Behaviour

MacCulloch’s Rainbowfish are peaceful, active and highly social fish that should always be kept in a group. We recommend at least six, although a larger shoal will usually result in more confident fish and much more interesting behaviour.

Males regularly display to both females and rival males by intensifying their colouration and extending their fins. These displays can look surprisingly dramatic but are normally just that – displays rather than serious aggression.

A mixed group containing several males can actually be particularly attractive, as the presence of rivals encourages males to show their best colouration. Providing plenty of females helps spread the attention of displaying males throughout the group.

They spend much of their time swimming through the middle and upper levels of the aquarium and make an excellent choice for planted community aquariums where an active shoal is wanted.

Tank Mates

MacCulloch’s Rainbowfish are excellent community fish and can be kept alongside other peaceful species with similar water requirements.

Suitable companions include smaller rainbowfish, peaceful barbs, rasboras, larger tetras, Corydoras and many peaceful loaches. Their relatively small adult size also makes them easier to incorporate into a community than larger rainbowfish species.

Very aggressive or considerably larger fish should be avoided, as should particularly slow or timid species that may be intimidated by the constant activity of the shoal.

Feeding

MacCulloch’s Rainbowfish are omnivorous and readily accept most aquarium foods. A quality flake or appropriately sized pellet can form the staple diet, supplemented with live and frozen foods such as brineshrimp, daphnia, mosquito larvae and small bloodworm.

Offering a varied diet helps maintain good condition and encourages mature males to display their strongest colouration.

Why We Recommend MacCulloch’s Rainbowfish

We particularly like MacCulloch’s Rainbowfish because they provide much of what makes larger rainbowfish so enjoyable in a considerably smaller package.

A good-sized group is constantly active without being troublesome, while displaying males provide plenty of colour and interesting social behaviour. They are particularly effective in planted aquariums where their movement contrasts beautifully against dense vegetation.

For someone looking for a peaceful shoaling fish that’s a little less commonplace than tetras or rasboras, they are an excellent option.

Frequently Asked Questions

How many MacCulloch’s Rainbowfish should I keep?

We recommend a minimum group of six, although eight or more is even better where aquarium space allows. Rainbowfish are highly social and generally become more confident and display more naturally when kept in a good-sized group.

How big do Melanotaenia maccullochi grow?

They are one of the smaller Melanotaenia species, generally reaching around 5–7cm when fully grown. This makes them considerably easier to accommodate than many rainbowfish that can exceed 10cm.

Are MacCulloch’s Rainbowfish aggressive?

No. They are peaceful community fish. Males frequently display and chase one another for short periods, particularly when females are present, but this is normal social behaviour and shouldn’t be confused with serious aggression.

Do MacCulloch’s Rainbowfish need to be kept in a shoal?

Yes. We wouldn’t recommend keeping them individually or as a pair. Their social interactions are an important part of their natural behaviour and a proper group will generally be considerably more confident.

Are MacCulloch’s Rainbowfish suitable for planted aquariums?

Absolutely. They look fantastic in planted aquariums and don’t generally cause problems for healthy plants. We recommend combining dense planting around the edges with plenty of open swimming space.

Can MacCulloch’s Rainbowfish jump?

Yes. Rainbowfish are capable jumpers, particularly if startled, so we strongly recommend keeping them in an aquarium with a secure lid.

If you have any questions about keeping the MacCulloch’s Rainbowfish, please contact us and a member of our team will be able to advise you.

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