Boesemani Rainbowfish (Melanotaenia boesemani) care sheet

Boesemani Rainbowfish

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Probably one of the most beautiful and popular species of freshwater fish is the Boesemani rainbow fish. These fish are easily identified by the male’s characteristic gradient of blue and orange. They are active schooling fish that make a great addition to planted tanks with plenty of open water for swimming.

Read on to find out everything you need to know about Boesemani rainbow fish, and how to keep a school of these colorful fish in your own freshwater aquarium!


Melanotaenia boesemani is commonly known as the Boeseman rainbow fish or the Boesemani rainbow fish. These fish belong to the Melanotaeniidae family, which are home to some of the most colorful tropical fish in the freshwater aquarium hobby.

With over 80 species belonging to the same genus as the Boesemani rainbow fish, there are many different shapes and sizes of rainbow fish. Although these fish come in many colors, they do not change color during their adult life and exhibit few colors independently of one another.

Natural habitat

The Boesemani rainbow fish comes from the warm waters of Indonesia. Their natural range is very limited and it is believed that they only occur in the regions around the Ajamaru Sea System in the western areas of the Bird’s Head Peninsula in West Papua, Indonesia.

There these fish train together in the shallower parts of the lake ecosystems and hide in the middle of dense vegetation. These lakes often have very hard and alkaline water, which means that the total mineral content is high and the pH is usually above neutral. While these fish are used to these parameters in this particular area of ​​Indonesia, they have also been found in bodies of water with very different water parameters.


In general, rainbow fish species are pretty easy to distinguish from other community fish. They typically have broad bodies with a sloping surface. Boesemani rainbow fish are usually easy to identify because of their distinctive blue and orange colors.

Male Boesemani rainbow fish are significantly easier to identify than female fish. Male Boesemani rainbow fish have a particularly deep body with two elongated dorsal fins. They sometimes have three noticeable dark blue stripes towards the front half of the body. Otherwise the body is almost equally even between metallic blue and yellow-orange.

Female Boesemani rainbows, on the other hand, are much less ornate, but still beautiful. Women are much less alive and do not have such a deep body. Instead, they usually have a greenish-brown back area that fades to white / silver on their lower abdomen. Like men, women can have two to three noticeable dark black or gray stripes behind their gills.

How big are Boesemani rainbows?

The Boesemani rainbow has a much deeper body than it is long and only grows to about 10.2 cm when fully grown. female Boesemani are usually slightly smaller, between 3 and 3 inches. Since many Boesemani rainbow fish are sold as hatchlings with uniform looks, it can be difficult to know how many males and females to get.

Keep in mind that while these fish are relatively small, they must be kept in schools that can quickly fill up space in a tank.

How long do Boesemani rainbow fish live?

Since the Boesemani rainbow can be relatively expensive for a school tropical fish, it’s comforting to know that with exceptional care it can live for over 5 years.

Requirements for the Boesemani rainbow fish tank

The best Boesemani rainbow tank setup is one that highlights the fish’s natural colors and behaviors. Some hobbyists believe that 30 gallons (113.6 L) is enough space to keep a healthy school of rainbow fish, but 40 gallons (151.4 L) give your fish plenty of swimming space while also allowing for thick vegetation and aquascaping.

Rainbow fish can be slightly more demanding than other tropical fish due to the natural hardness and alkaline pH of their natural ecosystems. While most rainbow fish have become accustomed to the more typical water parameters of home freshwater systems, it is always best to inquire about the preferred water conditions for these particular fish.

If your Boesemani rainbow fish needs special consideration, consider your pH between 7.0 and 8.0 (some hobbyists keep the pH at 9.0), water hardness between 10 and 20 ° H, and KH between 9 and 19 hold. The water temperature should be tropical and constant between 25 and 30 ° C.

Otherwise, these fish will appreciate the background of vegetation and mean water flow. To make their colors stand out even more, many hobbyists choose to leave them on darker surfaces.

Are Boesemani rainbow fish hardy?

In general, Boesemani rainbow fish are hardy. However, due to their more precise requirements for water hardness, pH, and water temperature, they can be a little more difficult to maintain and the parameters must be maintained. They don’t do well in softer, acidic water.

Also, remember that these fish cannot be kept alone and must be kept in a school. Otherwise, they can quickly become stressed and develop illness and / or die.

Boesemani rainbow fish tank mates

Rainbow fish are generally peaceful fish that do well in community aquariums with other fish that are similar in shape, size, and behavior. These fish come from a very specific ecosystem in Indonesia and the species with which they normally occur are rarely found in the hobby.

With the right gallon tank, there are many combinations you can make with Boesemani rainbow fish tankmates. However, you need to decide which types of species to keep first, as not all of these species are necessarily compatible with each other, although they will all suit Boesemani rainbow fish.

If you are going for a tank full of life, go for school types. This includes other rainbow fish (praecox / dwarf rainbow fish, turquoise rainbow fish), corydoras, danios (zebra danio, long-finned zebra danios), loaches, otocinclus and larger tetras such as congo tetras; Heavenly pearls danios can be added, but can be stressed out by overactivity. Most of these fish require large schools and are active throughout the day. So keep this in mind with the stocking!

On the flip side, you can keep Boesemani rainbow fish with more semi-aggressive species that may not do the best with smaller community fish. Some of these options include the rainbow cichlid, keyhole cichlid, and blue acara cichlid, especially since most cichlids prefer more alkaline water; Keep in mind that while these fish can be kept with Boesemani rainbow fish, not necessarily with each other.

Can you hold Boesemani rainbow fish together?

Yes! Having a school of Boesemani rainbow fish in your aquarium is actually a requirement for them to feel safe. In general, it is always best to have more women than men to prevent men from trying to get too much attention from women that will stress both fish.

That said, Boesemani rainbow fish are best for schools of six or more with fewer men than women. Boesemani rainbow fish can swim with other rainbow fish species, but they do best when kept in larger groups of their own species.

If you have a particularly active rainbow fish, adding more rainbows may help as these tend to settle down with larger numbers.

Boesemani rainbow fish behavior

Boesemani rainbow fish are active fish that need plenty of space to swim. Their large bodies and sudden movements can easily put stress on smaller, less active fish. They also tend to be pretty hideous and can react instantly to movement outside of the tank.

It should also be noted that these fish will show their best colors over time if the tank, diet, and ecosystem are right. However, due to the dwindling numbers in the wild, these fish were bred en masse in the aquarium hobby. As a result, this has resulted in a decreased quality of genes, resulting in strange behaviors and less vivid colors.

Boesemani rainbow fish diet

These fish are mostly omnivores and appreciate a mixed diet of plant and animal foods. While these fish look like they have big mouths, they cannot ingest larger foods because their necks become narrower.

Instead, you can offer a variety of live, frozen, and freeze-dried foods of appropriate sizes. They are particularly fond of insect larvae and worms such as blood worms and Tubifex worms. A good, high quality fish flake or pellet should be the staple food in order to give your fish the nutrients they need to keep the colors bright.

While these fish are omnivorous, they will not pick healthy, live plants in your aquarium. However, they pick up loose debris or dying leaves. You will also appreciate blanched vegetables like zucchini and spinach, as well as seaweed wafers or pellets from time to time.

Breeding Boesemani rainbow fish

Because of the declining populations in the wild and the simple beauty of these fish, the Boesemani rainbow fish is a popular and easy-to-breed fish in the home aquarium. While it is easy to breed, the brood is more difficult to breed than breeding a pair.

Boesemani rainbow fish are egg shakers, which means that the female lays eggs and the male fertilizes them. You will know your female rainbow is ready to spawn when her stomach is noticeably plumper. Males also become more intense in color and may develop a stripe on their heads as well as display one another. As soon as the conditions are right, the female spawns over vegetation, preferably over moss.

Spawning can continue for a few weeks for any female. After a week or two more, the roasts will hatch and begin to eat. Interestingly, adult Boesemani rainbow fish rarely eat their young. However, if you want more control and success over your brood, it is best to complete the breeding process in a separate tank.

The fry tend to stay on the water surface and in the vegetation. You can take infusoria initially and gradually transfer to larger foods like brine shrimp.


The Boesemani rainbow fish is one of the most beautiful fish currently available in the aquarium hobby. While they may need a little more care in terms of harsher and more alkaline water conditions, as well as more active tankmates, maintaining them is relatively easy and very rewarding. As long as you keep your Boesemani rainbow fish happy and healthy with a varied death, your fish will, in return, show its best possible colors!

If you have any questions about Boesemani rainbow fish or any other rainbow fish species, or if you have any experience with these colorful freshwater fish in your own aquarium, don’t hesitate to leave a comment below!

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