Boesemani Rainbow: A Care Guide To Our Vibrant Buddy

A Boesmani Rainbow fish in its natural habitat

Vibrant fishes with appealing colour combinations, and contrast, seem to get attention in the industry of aquariums. Boesemani Rainbow fish, also known as the Australian Rainbow fish, is a very colourful species. Well-known for their colourful appearance and quite attractive design, they put glory to the name.

Other than beautifying the aquarium perfectly, they are easy to care for, and that is how they appear to check all the boxes. We are here to make it even easier, and make everything you need to know available in our complete care guide, right on your finger-tips!

Key specifications

Before you proceed with the detailed article that follows, let us brief you real quick with some key specifications you must check:

Scientific NameMelanotaenia boesemani
OriginAjamaru Lakes and Aitinjo Lake are situated around the mountain ranges in the Vogelkop (Bird’s Head) Peninsula. Mostly found in West Papua and Raja Ampat islands, Indonesia. Eastern and Northern Australia, islands in Cenderwasih Bay, Madagascar, Sulawesi.
Lifespan5-8 years.
Colours/PatternsIridescent colouration like a blue, yellow or shiny silver. Commonly described as the blue head region with red rears.
SizeUp to 4.5 inches.
CompatibilityMostly compatible with similar fishes.
Tank sizeMinimum 30 gallons.
Care levelEasy
Water preferenceFreshwater


Scientifically known as the Melanotaenia boesemani, a Boesemani Rainbow is a species of Melanotaeniidae. These are small fishes with vibrant colours found in places starting from parts of Australia to Indonesia. Now we may know them to be different, but there is a belief in Hinduism of these cute variants we know of today. They used to be immense in size almost like a sea monster, but now entirely different, rather the opposite of it.

The family Melanotaeniidae consists of 81 species, and the Boesemani rainbow is one of them. They are freshwater fishes so putting them in tanks might be a complicated task at first but they are not complex to care for, under aquarium circumstances. 

Origin and Habitat of Boesemani Rainbow Fish

Originally belonging from parts of Indonesia and Australia, rainbowfishes are mostly found in densely plated vegetation with warm climate conditions and, not very deep water levels.

They stick to the regions with a shallow cover of nature, as in the deeper regions where there is an existing possibility of larger predators. The shallow regions provide a subtle level of security as they are middle dwelling species, like Tetras. Although, they are fast swimmers, which might result in slow-swimming species to feel a little anxious. It is recommended to pair them up with fishes who have similar characteristics and behavioural patterns, most importantly size.

Appearance of Boesemani Rainbow Fish

Relevant to their name, the rainbow fishes are very colourful and appealing to the eye. Their exquisite composition is fascinating, and their colour as a whole leans towards the iridescent range. The head section mostly showcases cool colours like purples, blues and greens. On the other hand, the rear has a warmer colour composition of orange, red and yellow.


They are not very big in size, growing for just up to 4.5 inches/11 cm, so they are comfortable in small or medium tanks. They although, are fast swimmers and this particular nature might call for the need for some space. Just to play it safe, a minimum tank of 30 gallons is recommended.


As we know, they represent an iridescent pallet on their body. Iridescent colour variants in fishes look very unique, and aesthetic. They look similarly appealing in the aquarium, as they do in their natural habitat, if taken well care of. If not, they might lose their colour. 

The head is mostly covered with cool colours like purples, blues and greens. On the other hand, the rear seems to have warm colour compositions of yellow, red or even orange. They might not be able to alter their colours, but the intensity of it can be controlled. A clear reflection of health, or even mood is clearly visible just from the intensity of colours on their body.

Intensity, if high, might indicate whether a fish is healthy or prepared to mate. If not, and the colour is towards the pale side, it might point towards some kind of stress or illness. There is a huge need for this particular species to have a nutritious diet, for the sake of their vibrancy.

Behaviour of Boesemani Rainbow Fish

They are mostly peaceful, but more than one male rainbow fish in the tank might cause some aggression issues. They are capable of even injuring each other around the time of mating. Boesemani Rainbow is a moderately hardy breed, but shy on their own, and a group of six, or perhaps eight appears to be a good number for the tank. A large shoal of this breed must be established to prevent stress, which might result in discolouration.

Although, they are relatively flexible when it comes to the choice of tank mates, they should preferably be kept with similar breeds. In easier terms, they must not be overpowered by other breeds in terms of size. It has also been recommended to not pair them up with fishes, of clashing nature. Aggressive fishes are better kept away, as they themselves do not pose any other behavioural threats or whatsoever.

Lifespan of Boesemani Rainbow Fish

They live a standard lifespan of about 5 to 8 years, but they are quite expensive. It is a good investment considering the fact they don’t have extremely complex special needs. They are mostly compatible as well and let us be honest, they are drop-dead gorgeous in the tank. Their handling can be easily done by a beginner aquarist, some research work is necessary.

Diet of Boesemani Rainbow Fish

The Boesemani Rainbow follow an omnivorous diet, so they are not very picky about their food choices, eating most things. The only factor that might lead to limitations in their textbook preference, is possibly their small mouths. Around the time of feeding, it is suggested to cut down the food in order to make the process easy.

To make It easy for you, here is a list of a few things you can add to their diet while feeding:

  • Small insect Larvae
  • Cut down plant matter.
  • Dried fish food like flakes or pellets.
  • Frozen fish feed-ables.
  • Mosquito Larvae
  • Daphnia
  • Spinach
  • Zucchini

Tank Requirements for Boesemani Rainbow Fish

To make the living conditions filled with comfort and appropriate for the rainbow fishes, the tank needs to be kept a certain way. The special needs are fortunately, not very complex.

Emulating the natural habitat in the aquarium is always a good idea.

Tank Lid

It is important to keep the tank lid in check, as they tend to jump, or leap quite often. If not careful enough, this movement characteristic of theirs might lead to an accident. Other than that tank lids, in general, protect the tank water from pollution.

Tank size

A minimum tank size of 30 gallons is recommended for their ease of movement. They are not very big, but they are active swimmers. Smaller spaces than the stated measurements, might limit them and make them feel uncomfortable. So, to play it safe, it is our suggestion to go up to 50-60-gallon tanks.


A substrate of sand is recommended if you wish to bring home, these beautiful beings. They are used to the dense vegetation scenario and a sandy base.


They do not seem to produce extensive amounts of waste, but they would certainly benefit from a strong filter. The pristine water has its own benefits to the breed.


It is good for the tank to be surrounded by float-able plants, preferably live, to make them feel at home. Otherwise, the addition of flowers or anything that is natural is always a good choice. It really increases the aquarium’s appeal, and makes the fish feel free, and comfortable. Rocks or figurines do just fine, as long as they do not overcrowd the tank environment, as they need open spaces to support their free-swimming nature.


Standard lighting works just fine, although the fishes may benefit heavily from natural sunlight.

Presence of Flora

There is no fish that does not like having vegetation in its vicinity. Still, overcrowding the tank with too many plants is not recommended, and a safe emulation of their natural habitat works well. Live rocks on the substrate are a good addition to keep it intact and in check.

Cleaning Method

The usage of chemical-based products is not necessary. They do not create a lot of waste, fairly regular or alternate cleaning should work. Cleaning and doing It right is extremely beneficial to the precious marine life, residing in the tank. It allows the fish to remain free of stress and healthy. To clear the filters, checking the water temperature and just an application of a soft piece of cloth, from time to time, does the job just fine.

Water Type for Boesemani Rainbow Fish

Shifting focus from the above-stated criteria, let us move on to the water profile that is necessary for the fellow breed, in order to appropriately survive under the aquarium situation. 

Their water parameters can be slightly demanding compared to other tropical fishes. To keep it all in one place, we present you some pointers you need to add, to keep your water requirements in check:

pHKeep it between 7.0-8.0 (can be max kept up to 9.0)
Hardness9-19 KH or 10-20 dH
TemperatureConstant and tropical temperatures are necessary, ranging from 25-30 Degrees Celsius
MineralNone as such.


A minimum pH of 7.0 is recommended, the range of up to 8.0 should be maintained. A balanced pH is good for fish health.


Water hardness of 9-19 dKH or 10-20 dH is good. The hardness of water is beneficial for mineral concentration. Hence, the right concentration is necessary.


25-30 Degrees Celsius is the desired temperature range that you must maintain. The temperature needs to be constant, as it plays a key role in the emulation of their natural habitat.


They do not have specific mineral requirements, but common beneficial minerals are always a good choice for addition to the tank.


Ideally, they are mostly compatible, yet they have some specifics. It is good if you keep them with fishes of similar size and energy. They are factually fast swimmers, and their movement routine might overwhelm some fishes sharing the tank with them.

Suitable Tank mates for Boesemani Rainbow Fish

They are usually shy, and they feel at their best when kept with the shoal. To prevent stress, and intimidation of the other breeds, and also for the compatibility sake of rainbow fishes, here are a few buddies that you can pair them up with:

Breeding of Boesemani Rainbow Fish

There is not much information available on the breeding, or reproduction process of this magnificent rainbow fish breed. Details on the mating system are mostly unknown. A Boseman’s Rainbow fish can be successfully bred in captivity, as per research.

They will typically move forward with the mating process, in a pair or a group. The males show more vibrancy around the head region, it flashes around this time. The females on the other hand typically lay about 20 eggs, minimum of ten. The process happens around the early morning period. It takes about two weeks for the eggs to hatch. The fry after birth can be fed yolk reserves.

Diseases of Boesemani Rainbow Fish

This particular type of rainbow fish is relatively hardy and does not have many problems, if kept under a well-maintained tank scenario. They are resilient beings, but they are not invincible.

A few of the commonly known diseases in rainbow fish include the White Spot Disease. Aside from diseases, stress can prove fatal too if kept unchecked for a certain period of time. Feeding excessive amounts of food, or failing to keep up with the suitable parameters, can cause negative nourishment, which may lead to certain death in them too.


Presenting you with some ways you can take care of your rainbow fish or prevent diseases from affecting them:

  • Ideal water temperature maintenance is necessary. Usage of an aquarium heater is recommendation, they need their water to be warm or else, it may lead to problems in health or even loss of colour.
  • We suggest you to keep them in groups to prevent stress.
  • There is a need for a safe lid. As they are fast swimmers, naturally, their leaping ability is risky. The absence of the same may lead to an unfortunate accident, which is not good.
  • The water parameters like nitrate levels, hardness or pH should be kept under check. An imbalance in that will make the fish prone to fatal diseases or death.
  • The male Australian rainbow fishes need to be well-monitored or isolated during the time of breeding. Their aggression can cause a fatal clash and loss.


Boesemani Rainbow or Australian Rainbow fishes are beautiful and delicate fishes, which can glorify the aura of every aquarium. Their iridescence in colouration and easy maintenance is something that makes it an aquarist, or, hobbyist favourite. Definitely worth the price, as they do not really have extraordinary needs. Not very hard to find, we highly recommend these fishes for your aquarium. It is a perfect pick, as it does not fail to check all the boxes you need to fulfil your tank criteria. 

Interersting Facts

The Boesmani Rainbow fish is endangered when it comes to numbers. They have a very unique trait of altering their colours as per their temperament, other than expressing ailment or stress, via fading or deepening of colours.

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