Boesemani Rainbow Stats InfographicThe Boesemani Rainbow, also known as Melanotaenia Boesemani or Boeseman’s Rainbow fish, is a vibrant fish with many fascinating colors that give life to your aquarium.

They are a famous sight in many aquaria thanks to their ease of care and their beauty. In ideal conditions, the Boesemani Rainbow can live for as long as 8 years in captivity.

With a little bit of research, you, yes, you as a beginner, can start an aquarium for Boesemani Rainbow fish.

To make it even easier, I am here to tell you all you need to know about caring for this fish.

Boesemani Rainbow Stats

Category Ratings
Care level Easy
Temperament Peaceful
Lifespan 5 to 8 years
Size  4.5 Inches
Diet  Omnivore
Tank Size Minimum of 30 gallons
Family Melanotaeniidae


The Boesemani Rainbow fish is a well-known freshwater fish species belonging to the Melanotaeniidae family. Within this family, there are several species, each having bright, rainbow-like colors.

The Boesemani Rainbow fish is endemic to the Ayamaru Lakes of Indonesia. They favor the tropical climate and can be found in only 3 lakes in Indonesia.

Regardless of their preference for the tropical lakes of Indonesia, you can raise Boesemani Rainbow fish easily in captivity. With as little as $5, you can pick up a Boesemani Rainbow from your local pet shop and begin your adventure of raising this beautiful fish.

– Appearance

Boesemani rainbow also known as melanotaenia boesemani or boesemans rainbow fishThe Boesemani Rainbow is shaped like a flat oval and has a narrow head at the front. They have enormous eyes, a small mouth, and tiny fins that jut out at the sides.

Their dorsal and anal fins start from the rear half of their body and end at the tail fin.
Looking at these fish, it is not difficult to see why they were dubbed “rainbowfish”. They have a colorful rainbow-like appearance that grabs your attention. The rear end of the Boesemani Rainbow features a host of warm colors like yellow, orange, and red.

Their head region, however, has an opposite coloration. Cooler colors like purple, green and blue adorn the heads of the Boesemani Rainbow fish. The stark contrast of colors on the front half and back half of this fish is why some aquarists refer to it as the bicolor Rainbow fish.

Their colors reflect their health and mood; thus, it is not uncommon to notice a Boesemani Rainbow with pale colors due to being stressed or ill. On the other hand, intense colors show that your fish is healthy or ready to mate.

– Dimorphism

The Boesemani Rainbowfish exhibits sexual dimorphism. The female is smaller than the male and has a brownish-green color. The male fish, on the other hand, is more brightly colored and has a yellow-blue appearance.

The abdomen of the female becomes rounded/plump when she is breeding while the male displays even brighter colors to attract the female to himself.

– Average Size

The Boesemani Rainbow is a small fish with an average size of 4 inches (10 cm) for males and around 3 inches for females. Regardless of their tiny size, they are very active and come into their own in a large tank.

– Can You Raise a Single Boesemani Rainbowfish?

Yes, it is possible to raise a single Boesemani Rainbow. However, it is not recommended. Why? You may ask. The simple reason is that the Boesemani Rainbow fish thrives in a community of at least 6 members.

So with just one, you will have a miserable, stressed-out fish. A stressed-out Rainbow fish is also more susceptible to common freshwater diseases and doesn’t look as bright as a healthy fish.

– How Many Should I Buy?

You should purchase a minimum of 6 Boesemani Rainbow fish for your aquarium. The more, the merrier. The Boesemani Rainbow tends to be shy and does not do so well when kept by itself. With anything less than 6 of them in a tank, you will notice that they keep to themselves and do not give off the radiant colors they are known for.

You should get up to 8 of these fish to establish a stress-free aquarium.

– Average Lifespan

With proper care and diet, the average Boesemani Rainbow lifespan is 5-8 years. In rare cases, some of these fish may even live for as long as 12 years! To ensure that you get the maximum Boesemani Rainbow lifespan, you must keep them in a healthy tank, with an environment as close to their natural habitat as you can get.

Boesemani Rainbow Care

Boesemani rainbow fishCaring for Boesemani Rainbow is a delight because they keep to themselves most of the time and do not require much attention from you. Also, the fact that they are hardy and undemanding makes them an excellent choice for beginner aquarists. However, like all fish species, Boesemani Rainbows require proper care to thrive.

In our article, you will find a simple care guide for the Boesemani Rainbow. Follow it, and you will have a shoal of happy fish.

– Tank Requirements

To successfully house the Boesemani Rainbow, you must first understand how it behaves and the environment in which it thrives. Boesemani Rainbow is very active. They need a large aquarium for them to swim to their heart’s content. The latter is pretty easy. They love tropical lakes and are hardy; therefore, they can survive in many habitats.

We recommend that you put them in a tank that has lots of plants and space for swimming. With a heavily planted tank, their colors tend to pop even more. Besides, it is a great way to mimic their natural habitat. These plants provide extra security for them, as well as a place for them to lay their eggs.

Let’s learn more about setting up the perfect tank for your Boesemani Rainbow.

1. Tank Size

Selecting the appropriate Boesemani Rainbow tank size is a crucial step in caring for the fish. Regardless of the Boesemani Rainbow’s small size, you will need a tank large enough to cater to all its swimming needs.

For a group of 6, you can make do with a 30-gallon tank. As your fish community grows, you will have to up your tank size. A rule of thumb is to add a minimum of 5 gallons for each fish you add to the aquarium. That way, they have enough open space to swim around.

2. Substrate

When setting up a tank for your Boesemani Rainbow, it makes sense to start from the very bottom, the substrate. However, since the Rainbow fish is not a bottom swimmer, you can use a suitable substrate for its tank mates. Sand, debris, and rock are great options for tank substrate. I especially prefer sand because it has a fine texture that is unlikely to scratch your fish.

3. Water Quality

The Boesemani Rainbow is not an overly messy fish. However, it can only thrive in a tank with excellent water quality like all fish species. To maintain a tank with pristine water conditions, you will need a high-quality filter.

There are loads of high-quality tank filters for you to choose from, and it can even get confusing. One hack is to choose a filter with a higher capacity than you need. That way, you won’t run into any troubles.

4. Equipment Needed

Asides from the filter, you will need a heater to keep the temperature between 81-86℉. You’ll also need to maintain a neutral pH of 7.0 – 8.0 for optimum fish performance.

You will also need a water testing kit for your tank to check the water parameters in the tank each week. That way, if there is a problem, you can catch it early before it affects your fish adversely.


Boesmani Rainbow fish make a great community. They are peaceful and compatible, but can move across the water rapidly in a manner that can stress other smaller, slow-moving fish. As a result of this swimming pattern, you must identify suitable tank mates for them. After all, you don’t want your tank filled with stressed fishes.

– Tank Mates

Another critical point to consider is Boesemani Rainbow compatibility. Simply put, you should give a lot of thought to the fish you introduce to your already established aquarium.

Owing to their narrow geographical range, the number of species encountered naturally is low. However, your choice of tank mate is not restricted to only species endemic to the Ayamaru lakes in Indonesia.

Ideal tank mates for the Boesemani Rainbow would be fish species of a similar size or smaller. You can try adding Tiger barbs, Corydoras Catfish, large Tetras, Danios, and other Rainbow fish to your tank.

Rift Lake cichlids are also suitable tank mates due to their similar water preferences. You can also place them with Assassin snails and Ghost Shrimps. In fact, this combo adds a different aesthetic to your tank.


The process of breeding Boesemani Rainbows is relatively easy because they do not eat their fry. The first step is to pair them up. For that, you will need to differentiate between the male and female Boesemani Rainbow.

The males are bigger and brighter than the females who are smaller and more streamlined. Once you have identified both sexes, you must move them into a special tank, the breeding tank.

The breeding tank is essential for conditioning the intended breeding pair. You need to pay special attention to their diet and water conditions. Their diet should consist of a steady stream of live and frozen foods.

– How to Condition the Breeding Tank

You should condition the tank such that the pH would be within the range of 7, with sufficiently hard water. Raise the temperature in the tank slightly. Elevated temperatures induce spawning in Boesemani Rainbows. One last thing, the tank should be heavily planted with Java Moss, Water Sprite, or any other equally densely growing plant.

– Boesemani Rainbow Fish Spawning

After a week of proper conditioning in the breeding tank, your Boesemani Rainbow fish will spend the next few days spawning on and off. The female lays between 10-20 eggs, and once the eggs are laid, the breeding pair tend to ignore the fry. Thus, it is advised that you remove the breeding pair after they have spawned. This way, it is easier to raise the fry.

It takes the fry about 1 week to hatch. Once hatched, you should feed them infusoria for at least a week. After the first week, you can feed the Boesemani Rainbow fish live food such as baby brine shrimp and other food that doesn’t sink immediately.


Boesemani Rainbow are omnivores in their natural habitat and are known to eat aquatic insects, small crustaceans, and algae. Thus, for their diet in captivity, you’d have to take care to recreate their “wild diet” as closely as possible. A great place to start is by feeding them high-quality flake food and live and frozen foods.

With live and frozen foods, you have lots of options to choose from. Our favorites are:

  • Daphnia
  • Blackworms
  • Mosquito larvae
  • Brine shrimps
  • Bloodworms

You can feed them dried, commercial food such as flakes and pellets in the absence of live or frozen food. These are convenient to obtain whilst providing your fish with all the range of nutrients it needs.

Don’t forget to include algae in their diet. Great options are chopped up zucchini or spinach. The plants in their tanks also provide a source of vegetables for them.

Remember, a regular stream of high-quality food ensures that your Boesemani Rainbow is not stressed, is healthy and happy. All of these translate into an even more active and colorful fish.

– Frequency of Feeding

Boesemani Rainbows should be fed tiny portions of food at regular intervals. The rule is to provide them with only what they can finish in minutes, at least twice a day. The portion control helps you prevent them from overfeeding; overfeeding results in overworking their digestive systems and leads to stress.

Common Diseases

The Boesemani Rainbow is susceptible to all of the common freshwater diseases, one of which is Ich. Ich, also known as white spot, is a disease caused by an ectoparasite.

The parasite causes the fish to break out white spots across its body, lose its appetite and, in some cases, develop cloudy eyes. Once you notice your fish showing any of these symptoms, quarantine it immediately and begin treating it.

– Preventing Diseases

There are a few trusted ways to prevent disease in your Boesemani Rainbow’s tank. For your convenience, I have outlined them below.

1. Buy From Trusted Dealers

Boesemani fish with great genetic makeup are more disease-resistant. They also sport brighter, more attractive colors. For this reason, I advise that you always get fish from a reputable pet store.

2. Quarantine New Fish

I always advise aquarists to treat each new fish as a potential disease carrier because some may already be infected from the pet shop. Thus, before you introduce them to your established tank, you need to quarantine them.

3. Quarantine and Sanitize Secondhand Equipment

Like new fish, secondhand equipment is a potential carrier of diseases. So, before you begin using them, you need to isolate and sanitize them thoroughly to kill any pathogens they may be harboring.

4. Maintain Pristine Water Conditions

When your tank is clean and the water conditions are within the recommended range, you rarely have issues with your fish getting sick. A reason for this is that pathogens cannot thrive in pristine water conditions.

4. Watch Their Diet

Yet another way to prevent disease in your Boesemani Rainbow tank is to ensure that they are fed a steady diet of high-quality food. Not just that, you should pay attention to the amount of food you give them at a go and how many times you feed them. The reality is that overfeeding in fish is just as deadly as underfeeding.


  • Boesemani rainbow fish in aquariumBoesemani Rainbows are small, peaceful, active fish, common to the shallow lakes of Indonesia, that keep you enthralled with their beauty.
  • They are egg scatterers and are easy to breed because they do not eat their eggs.
  • The Boesemani Rainbow fish is easy to care for, even for a beginner aquarist.

With the proper knowledge, anyone can raise a happy community of Boesemani Rainbow fish. We have provided insights to how you can care for this fish, breed it, and avoid falling prey to the usual freshwater diseases. Try this, and let us know how it works out in the comment section.

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