An incredibly popular and active schooling fish endemic to the Ajamaru Lakes in West Papua, Indonesia (currently listed as Endangered in the wild by the IUCN due to overfishing and habitat loss, though commercially captive-bred). Famous for the mature male's spectacular blue and orange split-coloration. They require long tanks for active swimming, excellent oxygenation, and warm, hard, alkaline water to thrive.
Boeseman's Rainbowfish At a Glance
Boeseman's Rainbowfish Tank Requirements
Will Boeseman's Rainbowfish fit in your tank?
Care guides tell you what Boeseman's Rainbowfish needs, the next question is whether your tank can safely provide it. Test Boeseman's Rainbowfish against your tank size, maintenance needs, and the fish you already keep before you buy.
Useful setup supplies
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Boeseman's Rainbowfish Water Parameters
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Boeseman's Rainbowfish Temperament & Compatibility
Boeseman's Rainbowfish Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Male
Adult males develop a highly arched back (deep body) and the iconic two-tone coloration: a bluish-purple front half and a vibrant orange-yellow rear. They continuously display to females and spar harmlessly with rival males. Best kept in a ratio of 1 male to 2 females, or in large groups.
Differs in 1 trait from base species
Also known as: Show Male, Adult Male
Female
Females are slightly smaller, more streamlined, and have subdued coloration (mostly silver/grey with yellowish fins and faint horizontal stripes). Keeping a proper female-heavy ratio reduces harassment stress and brings out the males' most intense display colors.
Differs in 1 trait from base species
Also known as: Female
Unsexed Juvenile
Most commonly found in stores at 3-5cm. Juveniles of both sexes are relatively colorless and silvery. It takes several months of high-quality diet and pristine water conditions for males to develop their characteristic deep body shape and dramatic colors.
Differs in 1 trait from base species
Also known as: Baby, Juvenile
Boeseman's Rainbowfish Care Guide Summary
The Boeseman's Rainbowfish, scientifically known as Melanotaenia boesemani, belongs to the Rainbowfish family group. Adults reach a maximum size of approximately 10 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 medium level of biological waste.
To thrive, the Boeseman's Rainbowfish requires a freshwater only aquarium with a minimum volume of 200 litres and a tank length of at least 120 cm. Water temperature should be maintained between 26°C and 30°C, with a pH range of 7–8.1 and a general hardness of 9–19 dGH. A moderate water flow is preferred.
The Boeseman's Rainbowfish is a rewarding species to keep, provided its core environmental needs are met. This species is available in 3 varieties: Male, Female, and Unsexed Juvenile. 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.
Boeseman's Rainbowfish Habitat Setup
When setting up an aquarium for the Boeseman's 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 light plant coverage for partial shade. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.
Boeseman's Rainbowfish Compatibility Notes
Classified as peaceful, the Boeseman's 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, 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.
Boeseman's Rainbowfish Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Boeseman's Rainbowfish.
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
125 Gallon Standard
150 Gallon High
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Frequently Asked Questions About Boeseman's Rainbowfish
How big does Boeseman's Rainbowfish get?
Boeseman's Rainbowfish (Melanotaenia boesemani) typically reaches a maximum adult size of approximately 10 cm. They have a compressed body shape and a moderate growth rate.
What tank size does Boeseman's Rainbowfish need?
A minimum aquarium volume of 200 litres and a tank length of at least 120 cm are recommended for Boeseman's Rainbowfish. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Boeseman's Rainbowfish need?
Boeseman's Rainbowfish thrives in freshwater only conditions with a temperature range of 26–30°C, a pH between 7 and 8.1, and a general hardness of 9–19 dGH. A moderate water flow is preferred.
Is Boeseman's Rainbowfish peaceful or aggressive?
Boeseman's 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 Boeseman's Rainbowfish should be kept together?
Boeseman's 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 Boeseman's Rainbowfish have any special tank requirements?
Yes. Boeseman's Rainbowfish benefits from plants - lighly covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Boeseman's Rainbowfish need a lid on the tank?
Yes. Boeseman's 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 Boeseman's Rainbowfish
These fish are strong compatibility matches for Boeseman's Rainbowfish based on water preferences, temperament, adult size, and tank behavior.
Zebra Shovelnose (Tigrinus Catfish)
Brachyplatystoma tigrinum
Ideal Tank MatesEmerald Green Cory
Corydoras splendens
Ideal Tank MatesAngelicus Botia
Botia kubotai
Ideal Tank MatesBengal Loach
Botia dario
Ideal Tank MatesAsher Cory
Corydoras tukano
Ideal Tank MatesMalaysian Trumpet Snail (MTS)
Melanoides tuberculata
Ideal Tank MatesPlants That Suit Boeseman's Rainbowfish
These plants pair well with Boeseman's Rainbowfish based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
African Onion Plant
Crinum calamistratum
Afzel's Anubias
Anubias afzelii
Anacharis
Egeria densa
Baby Tears
Lindernia rotundifolia
Balansae
Cryptocoryne crispatula
Belinda's Buce
Bucephalandra belindae
Fish Similar to Boeseman's Rainbowfish
Ajamaru Rainbowfish
Melanotaenia ajamaruensis
A highly active, schooling rainbowfish endemic to the Ayamaru Lakes in West Papua, Indonesia. Currently listed as Critically Endangered in the wild. It is closely related to Boeseman's Rainbowfish but possesses a notably more slender body and more prominent reddish-brown horizontal striping. They thrive in hard, alkaline water with dense vegetation and require significant horizontal swimming space.
Lake Wanam Rainbowfish
Glossolepis wanamensis
A critically endangered species (IUCN Red List) endemic to Lake Wanam in Papua New Guinea. Known for the extreme deep-bodied shape and metallic green-bronze colors that mature males develop. They are fast, active schooling fish that require hard, alkaline water and plenty of swimming space. Excellent for large planted aquariums.
Lake Tebera Rainbowfish
Melanotaenia herbertaxelrodi
A striking, highly active schooling fish endemic to Lake Tebera in Papua New Guinea. They feature bright yellow to greenish-blue bodies with a distinct dark lateral stripe. As vigorous swimmers, they require long aquariums and do best in mixed-sex shoals, which encourages males to display their best colors. Due to their highland origin, they prefer slightly cooler, well-oxygenated, and alkaline water.
Lake Mbuta Rainbowfish
Pelangia mbutaensis
A very rare and Critically Endangered rainbowfish endemic to the swampy Lake Mbuta basin in West Papua, Indonesia. It is the sole member of the genus Pelangia. Characterized by a yellowish-tan body grading to silvery-white, they are peaceful, active schooling fish. They are virtually unseen in the standard aquarium trade.
Bleher's Rainbowfish
Chilatherina bleheri
A stunning, highly active schooling fish endemic to Lake Holmes (Danau Bira) in Papua, Indonesia. Known for its distinct dual-coloration, with the front half being greenish-blue and the back half turning a vibrant red/orange. They are famously active darters and require long tanks with significant open swimming space and well-oxygenated water.
Turquoise Rainbowfish
Melanotaenia lacustris
A stunning, deep-bodied rainbowfish endemic to Lake Kutubu in Papua New Guinea. Famous for their ability to shift colors from deep teal to bright iridescent blue depending on mood and water quality. They are active schooling fish that thrive in hard, alkaline water.