Information, Freshwater fish, Rainbowfish, Species

Boesemani Rainbowfish (Melanotaenia boesemani)

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by Jason Matthews



The Boesemani rainbow fish is a true jewel in the world of aquariums. Whether you’re a novice or an experienced fish keeper, the Boesemani rainbow fish will win your heart and add a new level of beauty and excitement to your tank.

This article will explore everything you need to know about this beautiful species, including its origin, appearance, size, behavior, tank conditions, tankmates, diet, breeding, and potential diseases. So sit back and get ready to learn about the Boesemani rainbow fish!


Scientific Name: Melanotaenia boesemani
Common Names: Boeseman’s rainbowfish, Boesemani rainbowfish, Boesemani rainbow
Life Expectancy: 5 years
Adult Size: 11 cm (4.4 inches)

Characteristics of Boesemani Rainbowfish

HabitatLowland rivers and streams
OriginPapua New Guinea
Care LevelModerate
Tank LevelMiddle to Bottom
Minimum Tank Size20 gallons (75 liters)
Water pH7.0 to 8.0
Water Temperature74 to 82°F (23 to 28°C)
Water Hardness5 to 15 dGH
Tank MatesPeaceful, similar-sized species

Fun Fact Corner

Did you know that the Boesemani rainbow fish is known for its stunning and vibrant coloration, but these colors are only visible when the fish are in their breeding mood? During this time, their coloration becomes even more intense, making them an even more beautiful sight in the aquarium. 


The Boesemani rainbow fish is native to Papua New Guinea’s rivers and streams, where it has lived for thousands of years. This region is known for its diverse and unique ecosystem, and the Boesemani rainbow fish is just one of the many incredible species found there. The clear and pristine waters of its native habitat provide the perfect environment for this fish to thrive.

Appearance & Size

The Boesemani rainbow fish has a streamlined, elongated body with shimmering scales in various colors, including blue, green, red, and yellow. They are distinguished by their iridescent blue eyes, which add a touch of radiance to their overall appearance. 

The Boesemani rainbow fish is a relatively small species, with adult fish typically reaching a maximum length of around 4-5 inches (10-12 cm). This makes them a great choice for aquariums of modest size, as they only require a little space to swim and thrive.


The Boesemani rainbow fish is sexually dimorphic, which means that male and female individuals differ physically.

Male Boesemani rainbow fish are typically more colorful and have more prominent fins than females. They also have a slimmer, more streamlined body shape than females, with more rounded bodies. Males use their bright colors and impressive fins to attract mates and establish dominance in their social groups.

Conversely, females are less colorful but larger and more robust, making them better equipped to care for their eggs and fry. 


The Boesemani rainbow fish are peaceful but can be territorial, particularly during mating season. Boesemani rainbow fish live in schools in the wild and have a strong social hierarchy with dominant males and submissive females.

They are active swimmers who will spend much time exploring their tank and engaging in courtship and territorial displays.


When selecting tankmates for the Boesemani rainbow fish, choosing compatible species in terms of water conditions, size, and temperament is important. It is important to avoid keeping them with larger or aggressive species and slow-moving or sedentary species that may be bullied or outcompeted for food.

Here are some good tankmates options for the Boesemani rainbow fish:

  • Other peaceful community fish, such as tetras, rasboras, or gouramis
  • Catfish such as Corydoras or Bristlenose Pleco
  • Shrimp or snails
  • Live plants provide additional hiding places and help regulate water conditions

Tank conditions

The Boesemani rainbow fish is native to New Guinea’s fast-flowing rivers and streams, and they require specific water conditions to thrive in an aquarium. They prefer a well-filtered, well-oxygenated environment with a pH of 6.5 to 7.5 and temperatures ranging from 72 to 82°F (22 to 28°C).

Maintaining good water quality through regular water changes and a high-quality filter is also critical. A minimum of 20 gallons of tank space is recommended for a small school of Boesemani rainbow fish, with larger tanks providing more swimming space.


The Boesemani rainbow fish are omnivores who require a varied diet. In the wild, they eat a variety of small insects, crustaceans, and plant matter, and in the aquarium, they will accept flakes, pellets, and frozen and live food.

A high-quality staple diet of flakes or pellets, supplemented occasionally with frozen or live food treats, will provide a balanced and varied diet for your Boesemani rainbow fish. Brine shrimp, daphnia, and bloodworms are good frozen or live food options.

Avoid overfeeding because it can lead to poor water quality. Instead, aim to feed your fish small, frequent meals throughout the day and be mindful of how much your fish consume to ensure they remain healthy.


Breeding Boesemani rainbow fish can be a rewarding experience for experienced fishkeepers. These fish are considered relatively simple species to produce in the home aquarium. 

The most important factors in breeding are water temperature and pH. Rainbow fish prefer temperatures ranging from 76 to 82 degrees Fahrenheit and a pH of 7.0 to 7.5. These conditions will create a suitable breeding environment and increase the chances of successful breeding.

It is also recommended to provide plenty of hiding places for the fish to lay their eggs, such as caves and plants, to encourage breeding. A breeding cone can also be used to provide a specific area for the female to lay her eggs.

Once the eggs have been laid and fertilized, the adults must be removed from the breeding tank to prevent the eggs from being eaten. The eggs hatch in 3-5 days, and the fry can swim in another 5-7 days. They should be fed small, live, or frozen foods like brine shrimp or daphnia until they are large enough to accept other foods.


The Boesemani rainbow fish is a hardy species, but like all fish, they can still be susceptible to certain diseases. To help prevent illnesses, keep their tank conditions optimal, with good water quality and temperature. 

Bacterial, parasitic, and fungal infections are common diseases in Boesemani rainbow fish. It is critical to watch for signs of illness in your fish, such as lethargy, loss of appetite, or changes in color or appearance. If you suspect your Boesemani rainbow fish is sick, consult a veterinarian specializing in fish health for an accurate diagnosis and treatment plan.


Jason Matthews

My name is Jason Matthews, and welcome to my website. When other kids were bragging about how their dog could sit and roll over, I was bragging about my latest Betta Fish and the cool sea castle I just added to his aquarium. 

Jason aquariume

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