A smaller, peaceful species of rainbowfish native to Australia and Papua New Guinea. They feature striking silver/yellow bodies with horizontal red, brown, or orange stripes. Unlike larger Melanotaenia species, their smaller size makes them suitable for medium aquariums. They are highly active schooling fish that require open swimming space and display their best colors in the morning.
MacCulloch's Rainbowfish (Dwarf Rainbowfish) At a Glance
MacCulloch's Rainbowfish (Dwarf Rainbowfish) Tank Requirements
Will MacCulloch's Rainbowfish (Dwarf Rainbowfish) fit in your tank?
Care guides tell you what MacCulloch's Rainbowfish (Dwarf Rainbowfish) needs, the next question is whether your tank can safely provide it. Test MacCulloch's Rainbowfish (Dwarf Rainbowfish) against your tank size, maintenance needs, and the fish you already keep before you buy.
Useful setup supplies
We may earn from qualifying purchases
MacCulloch's Rainbowfish (Dwarf Rainbowfish) Water Parameters
Water care products
We may earn from qualifying purchases
MacCulloch's Rainbowfish (Dwarf Rainbowfish) Temperament & Compatibility
MacCulloch's Rainbowfish (Dwarf Rainbowfish) Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard
The standard MacCulloch's Rainbowfish. Best kept in a mixed-sex school where males will spar harmlessly and display their brightest colors to attract females. A tight-fitting lid is required due to their jumping capability.
Same care requirements as the base species
Also known as: Mixed, Unsexed, Wild Type
MacCulloch's Rainbowfish (Dwarf Rainbowfish) Care Guide Summary
The MacCulloch's Rainbowfish (Dwarf Rainbowfish), scientifically known as Melanotaenia maccullochi, belongs to the Rainbowfish family group. Adults reach a maximum size of approximately 7 cm and have a compressed 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 MacCulloch's Rainbowfish (Dwarf Rainbowfish) requires a freshwater only aquarium with a minimum volume of 80 litres and a tank length of at least 80 cm. Water temperature should be maintained between 20°C and 30°C, with a pH range of 5.5–8 and a general hardness of 5–15 dGH. A moderate water flow is preferred.
The MacCulloch's Rainbowfish (Dwarf Rainbowfish) is a rewarding species to keep, provided its core environmental needs are met. The MacCulloch's Rainbowfish (Dwarf Rainbowfish) is typically available in one standard form.
MacCulloch's Rainbowfish (Dwarf Rainbowfish) Habitat Setup
When setting up an aquarium for the MacCulloch's Rainbowfish (Dwarf 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.
MacCulloch's Rainbowfish (Dwarf Rainbowfish) Compatibility Notes
Classified as peaceful, the MacCulloch's Rainbowfish (Dwarf Rainbowfish) is a schooling species that feels most secure in a sizeable group, where natural shoaling behaviour reduces stress and brings out their best colours. When choosing tankmates, 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.
MacCulloch's Rainbowfish (Dwarf Rainbowfish) Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for MacCulloch's Rainbowfish (Dwarf Rainbowfish).
30 Gallon Breeder
40 Gallon Breeder
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
Show 12 more tank sizes
Feeding products
We may earn from qualifying purchases
.webp?2026-04-25T14%3A35%3A38.022Z)
Frequently Asked Questions About MacCulloch's Rainbowfish (Dwarf Rainbowfish)
How big does MacCulloch's Rainbowfish (Dwarf Rainbowfish) get?
MacCulloch's Rainbowfish (Dwarf Rainbowfish) (Melanotaenia maccullochi) typically reaches a maximum adult size of approximately 7 cm. They have a compressed body shape and a moderate growth rate.
What tank size does MacCulloch's Rainbowfish (Dwarf Rainbowfish) need?
A minimum aquarium volume of 80 litres and a tank length of at least 80 cm are recommended for MacCulloch's Rainbowfish (Dwarf Rainbowfish). This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does MacCulloch's Rainbowfish (Dwarf Rainbowfish) need?
MacCulloch's Rainbowfish (Dwarf Rainbowfish) thrives in freshwater only conditions with a temperature range of 20–30°C, a pH between 5.5 and 8, and a general hardness of 5–15 dGH. A moderate water flow is preferred.
Is MacCulloch's Rainbowfish (Dwarf Rainbowfish) peaceful or aggressive?
MacCulloch's Rainbowfish (Dwarf Rainbowfish) is classified as peaceful with an aggression score of 2 out of 10. They are generally well-suited to peaceful community tanks.
How many MacCulloch's Rainbowfish (Dwarf Rainbowfish) should be kept together?
MacCulloch's Rainbowfish (Dwarf Rainbowfish) is a schooling species and should be kept in groups of at least 6. Larger groups help distribute aggression and encourage natural schooling behaviour.
Does MacCulloch's Rainbowfish (Dwarf Rainbowfish) have any special tank requirements?
Yes. MacCulloch's Rainbowfish (Dwarf Rainbowfish) benefits from plants - densely covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does MacCulloch's Rainbowfish (Dwarf Rainbowfish) need a lid on the tank?
Yes. MacCulloch's Rainbowfish (Dwarf 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.
Top Tank Mates for MacCulloch's Rainbowfish (Dwarf Rainbowfish)
These fish are strong compatibility matches for MacCulloch's Rainbowfish (Dwarf Rainbowfish) based on water preferences, temperament, adult size, and tank behavior.
Dainty Cory (Salt and Pepper Cory)
Corydoras habrosus
Ideal Tank MatesZebra Shovelnose (Tigrinus Catfish)
Brachyplatystoma tigrinum
Ideal Tank MatesIncolicana Corydoras
Corydoras incolicana
Ideal Tank MatesEmerald Green Cory
Corydoras splendens
Ideal Tank MatesDuplicareus Corydoras
Corydoras duplicareus
Ideal Tank MatesLoxozonus Corydoras (C079/C082)
Corydoras loxozonus
Ideal Tank MatesPlants That Suit MacCulloch's Rainbowfish (Dwarf Rainbowfish)
These plants pair well with MacCulloch's Rainbowfish (Dwarf Rainbowfish) based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Afzel's Anubias
Anubias afzelii
Amazon Sword
Echinodorus amazonicus
Anacharis
Egeria densa
Anubias Barteri
Anubias barteri
Baby Tears
Lindernia rotundifolia
Balansae
Cryptocoryne crispatula
Fish Similar to MacCulloch's Rainbowfish (Dwarf Rainbowfish)
Dwarf Neon Rainbowfish (Praecox)
Melanotaenia praecox
A brilliant, active schooling fish native to the Mamberamo River basin in West Papua. Known for their iridescent neon-blue bodies, they are an energetic and peaceful addition to community tanks. Because of their high activity levels, they require ample open swimming space alongside planted areas. They are fast eaters and may outcompete shy tank mates for food.
Eastern Rainbowfish
Melanotaenia splendida
An active, schooling species native to Australia, highly variable in color depending on the catch location. They are fast swimmers that require long tanks with ample open swimming space. Because of their energetic feeding behavior, they can outcompete shy or slow-moving fish. Best kept in shoals to display natural morning sparring and courtship behaviors.
Allen's Rainbowfish
Chilatherina alleni
A rare and highly active rainbowfish native to West Papua, Indonesia (Wapoga River basin). Known as the 'Wapoga Rainbowfish', they undergo a dramatic color transformation as they mature, developing intense metallic blues, greens, and reds. As exceptionally fast, continuous swimmers, they require a 4-foot (120cm) aquarium minimum to thrive without stress.
Black-Banded Rainbowfish
Melanotaenia nigrans
The Black-Banded Rainbowfish is a lively, peaceful schooling fish native to northern Australia. Recognized as the first scientifically described species in its genus, they are prized for their dark mid-lateral stripe and energetic swimming behavior. They are highly adaptable, occurring in freshwater streams and occasionally brackish estuaries in the wild.
Dwarf Rasbora
Boraras maculatus
A tiny, peaceful shoaling fish native to the blackwater streams and peat swamps of Southeast Asia. Known for their striking red/orange coloration and distinct dark body spots. They are an excellent choice for heavily planted nano tanks and peaceful dwarf shrimp setups. Because of their minute size, they are easily outcompeted for food and predated upon by larger fish.
Threadfin Rainbowfish
Iriatherina werneri
A delicate and exquisitely shaped nano rainbowfish native to New Guinea and Northern Australia. They are famous for the males' long, filamentous fins and butterfly-like display behavior. Due to their incredibly small throats, they require micro-foods. They are shoaling fish that are easily intimidated by boisterous tank mates.