Boesemani rainbowfish care guide

Boesemani rainbow (Melanotaenia boesemani) comes from Melanotaeniidae family. This is a bright, active and schooling fish. It is quite challenging in terms of keeping, therefore it’s not recommended for beginner aquarists.

Habitat in the wild

The boesemani rainbowfish inhabits West part of New Guinea (West Papua) island, the territory of today’s Indonesia. Only three habitats of the fish are known nowadays. These are three lakes known as Ajamaru, Hain and Aitinjo.

The fish prefers shallow waters with thickly growing aquatic vegetation. These fish tend to stay among the plants where they feed on vegetation and insects. In the wild the boesemani rainbowfish is at threat of extinction. Currently fishing and exporting this fish species is prohibited in the country. Most of rainbowfish that you see on sale were bred in fish hatcheries.

Scientific NameMelanotaenia boesemani
Common NamesBoeseman’s rainbowfish, Boesemani rainbowfish, Boesemani rainbow
Ease of keepingMedium
Lifespanup to 5 years
Tank size120 liters (26,4 gallons and more)
Tank typeCommunity of fishes
Temperature24-26 °C (75.2-78.8 °F)
Water hardness9–20 dGH
Sizeup to 11 cm (4.4 inches)


Boesemani rainbowfish adult species grow up to 8–11 cm (4.4 inches) long. The lifespan depends on the tank conditions and can be about 5-6 years.

This boesemani rainbowfish has tall, flattened, ellipsoid-shaped body. Its dorsal consists of two parts: small one and elongated one. The anal fin is symmetrical to the elongated part of the dorsal. The tail fin is forked, the head is narrow with large eyes.

The body coloring is quite unusual – its head and the part of the body behind it is light blue, which transforms into yellow-orange color starting from the middle of the body to its tail. The males are larger and have more intensive coloring.

Difficulties in keeping

The boesemani rainbowfish is rather demanding in terms of feeding and keeping conditions. It requires stable tank water parameters and quality food. For this reason, the fish isn’t recommended for beginners, since to keep it successfully you need some experience and ability to maintain tank water parameters stable.

Care and keeping in a tank

Tank size

The tank should be at least 120 liters (26,4 gallons) large. Considering that the fish prefers having a company of its kind, it’s better to keep it in a school of at least 6-8 species or more. This way the fish demonstrates brighter coloring and natural behavior features. The tank should be elongated and large.

Tank decor

The boesemani rainbowfish feels comfortable in tanks with large number of tank plants, but at that they should have plant free areas for the fish to swim. Sandy bottom, lots of plants and snags – this is a biotope that resembles New Guinea waters.

As for the tank plants, choose small leaved ones and put them along the tank perimeter to leave the area to swim. To prevent the fish jumping out of the tank, the latter should have a lid. Intensive filtration and aeration, proper lighting as well as weekly renew of 1/3 of tank water is a must.

Water parameters

The boesemani rainbow is quite sensitive to water parameters and ammonia and nitrates content in the tank water. It is desirable to use external filter, at that the fish likes presence of the water flow is a tank, so you don’t have to reduce the flow rate.

Here are the proper tank water parameters: temperature 24-26 °C (75,2-78,8 °F), ph: 6.5-7.5 , 8 — 25 dGH.

If you don’t provide the fish with favorable tank conditions, its coloring will become dim and the boesemani rainbowfish will look less appealing.


This fish species isn’t demanding in terms of food and it’ll eat all types of popular fish food – artificial, live and frozen one.

However, quality and composition of the food has a direct impact on the fish coloring, that’s why it is recommended to use only high quality food of well known manufacturers and regularly (at least once a week) give live food to the boesemani rainbowfish (for example, tubifex or bloodworm).

Except live food it’s desirable to enrich the diet with vegetable components, such as lettuce leaves or spirulina containing artificial food.

Tank mates

This is a peaceful and active species that gets on perfectly well with other fishes of the same size and temper, capable of living at the same tank conditions. For example: angelfish, gourami, neon tetra, betta, even discus.

The boesemani rainbowfish should be kept in a school of at least 6-8 species of both genders. It was noticed that males demonstrate brighter coloring if rivals are present in a tank.

Gender differences: male vs female

The boesemani rainbowfish males are larger and brighter colored. The females are not that glamorous and their body is completely dark blue colored.


Optimal conditions for breeding are the following: hard and a bit acidic water (pH 7.5), temperature 27–29°C, regular feeding with live food, small leaved and short-growing plants or artificial plants with the same characteristics.

First put one or two females into a spawning tank and several hours later put 2-3 males. The spawning period lasts for about 2 weeks and during this time the female lays several eggs among the tank plants at every turn and they stick to their leaves.

The boesemani rainbowfish male can fertilize several clutches of different females at the same time.

The boesemani rainbowfish don’t demonstrate any parental instincts. So, when the spawning is over they don’t show any concern about their offspring, however, they don’t tend to harm either their eggs or juveniles as well. But we can’t say the same about their tank mates, which can eagerly eat both the eggs and the juveniles.

In order to preserve the offspring, carefully put the eggs into another volume with the same water parameters and there the eggs will be safe. The egg stage lasts from 7 to 12 days.

During the first days of their life the juveniles will need micro sized food, such as infusorian. As the juveniles grow you can feed them with specialized powderlike food or/and brine shrimp nauplii.