Turquoise Rainbowfish Care Guide & Species Profile

Turquoise Rainbowfish is one of the most gorgeous fish found in Lake Kutubu.

Lake Kutubu Turquoise Rainbowfish is one of the most distinct and stunning rainbowfish species. It is a wonderful addition to a planted or community aquarium!

Rainbowfish are among the most exotic kinds of fish that you can keep. Of all the kinds, Turquoise Rainbowfish look the most vibrant and attractive, thanks to their deep blue colors.

At 4.9-inches long, these fish have amazing color-changing characteristics. They should be kept as schooling fish in a 30-60-gallon tank that has an omnivore diet and suitable water conditions.

Turquoise Rainbowfish Overview

Level of CareModerate
AppearanceThey typically tend to have a cobalt blue or a teal-colored tone at the top that fades to a silverish, greenish, or yellowish hue at the bottom.
TemperamentExtremely violent or aggressive if maintained in a tank with a suitable partner.
Lifespan5-8 years
The average purchase size is:2 inches (5 cm)
Tank Size55 gallons (for a school of 6 to 8 adults)
Tank EnvironmentA hard alkaline water condition that is accompanied by dense plantation
Tank MatesPeaceful
Temperature68deg – 77deg F (20deg – 25deg C)
pH7.0 – 8.5
KH10 – 20 dKH
OriginTank-Bred is a native of Lake Kutubu, Papua New Guinea

The Lake Kutubu Turquoise Rainbowfish (Melanotaenia lacustris) is a vibrant species that is adored by the deep turquoise, blue and yellow hues.

It’s a highly active fish, which lives in schools of Papua New Guinea’s Lake Kutubu and the connected River Soro, both of which are calm lakes.

Like most rainbowfish, males and females are extremely vibrant However, mature males have deeper bodies and the most vibrant colors.

It is believed that the Lake Kutubu Turquoise Rainbowfish is tranquil with other fish species, however, its size and activities can make it a bit intimidating for timid fish.

It’s likely to prey on dwarf shrimp and bamboo shrimp, but it is usually secure to keep it with peace-loving invertebrates which are not large enough to be considered to be prey.

The most vivid colors will be visible when the species is housed within schools of 6 or more and includes multiple males in a large, planted aquarium to ensure males who are subdominant do not get intimidated by dominant males.

As with other rainbowfish, the use of a darker substrate will also often produce better color. This fish is highly versatile, however, it shouldn’t keep it in soft or acidic water.

The natural habitat of Lake Kutubu Turquoise Rainbowfish possesses crystal clear waters with plenty of limestones derived through underground water springs. That’s the reason why the pH range of the natural habitat is somewhat alkaline.

Also known as the scientific title, Melanotaenia Lacustris, Turquoise Rainbowfish is well-known for its distinctive body shape. The body of the fish is very long, and it tends to get deeper in the course of its aging.

Turquoise Rainbow Fish Appearance

The distinctive characteristics of this species are its head. The body of a male who is older Turquoise Rainbowfish is not at all likely to follow the circular contouring lines of its body.

Instead, it will show out with a more narrow with a more triangular head.

Their eyes merit an extra mention because they are large and important. Additionally, Turquoise Rainbowfish have quite impressive dorsal fins.

Additionally being a great fish, Lake Kutubu Turquoise Rainbowfish are capable of displaying a variety of shades. They are, however, famous because of their exotic dark blue color.

The name Blue Rainbowfish comes from their particular appearance.

They usually sport a cobalt blue or a teal tone from the top which fades to a silver, green or yellow color at the bottom.

Starting from the rear part of their tails, Turquoise Rainbowfish usually have a thin cobalt blue stripe, which tends to disappear around the middle of their bodies.


Turquoise Rainbowfish are usually not tiny. They have a moderate length. They can grow as large as 4.9-inches (or 12.47 cm in length.

Social Behaviors

The Melanotaenia Lacustris species are described as a community fish. They are naturally playful and exuberant.

The Turquoise Rainbowfish are more susceptible to becoming aggressive and territorial according to the other members of a community tank.

It is believed that the Lake Kutubu Rainbowfish can adapt to life in a bigger fish community aquarium but does exceptionally well in the geographical tank stocked with other rainbowfish.

They must be mixed with fish that share similar temperament and size. These fish are active and boisterous. This behavior can quickly turn into aggression and violence with unsuitable tank friends.

These fish grow larger than common fish and their schooling moves could easily cause stress to other tankmates.

Because these are schooling fish so the ratio of males and females is crucial to maintain a healthy peace between them. While you are able to maintain single breed fish schools you’ll have better color if both genders are included in the tank.

Here are the following numbers that we consider to be the ideal stocking quantities in the case of schooling rainbow fish. Pick the kind of school you would like to keep and the number of fish you want to keep.

If you’d like to continue…

  • 5 rainbowfish – Don’t mix genders
  • 6 rainbowfish – 3 males + 3 females
  • 7 rainbowfish – 3 males + 4 females
  • 8 rainbowfish – 3 males + 5 females
  • 9 rainbowfish – 4 males + 5 females
  • 10 rainbowfish – 5 males + 5 females


These fish species, Turquoise Rainbows, are very hardy by their nature. They typically have a longer lifespan than other species of freshwater fish.

In general, the Turquoise Rainbowfish comes with an average lifespan of around 5 years. However, these fish are also able to live for up to 8 years in a properly maintained tank, subject to the right maintenance and diet.

Tank Requirements

Rainbowfish aren’t particularly difficult to take care of if the water they drink is in a clean state. At least 25 – 50% of the tank’s water needs to be changed every week, particularly when the tank is heavily filled.

They are extremely active swimmers, and they also love to jump So make sure that the tank is secured with a cover.

  • Water Changes Weekly – Weekly water adjustments between 25 – 50%, dependent on the density of the stock.

Melanotaenia lacustris, a blue rainbow fish, is known to engage in extreme swimming. Therefore, it is important to make sure that you provide them with the proper maintenance in your aquarium.

The tank you select for this fish must be spacious enough in it.

Also, ensure that the tank you select to house your Rainbowfish Melanotaenia Lucustris comes with a suitable cover to ensure they are secured inside the tank.

The Lake Kutubu rainbowfish melanotaenia lacustris generally requires a cleaner water environment to live a long and healthy existence.

Therefore, it is recommended to install a filter for the water in your aquarium to ensure proper water flow within the tank.

The Lake Kutubu rainbowfish melanotaenia lacustris should have a smooth substrate for improved care for the tank. Also, you must ensure that the substrate is sufficiently dark so that the fish will show better coloration.

They also prefer dense vegetation and bogwood, which helps them to mimic the natural habitat in Papua New Guinea.

The rainbowfish, melanotaenia lucustris, usually prefer an aquarium with a good plant for better treatment. This Rainbowfish species is tolerant of tough and alkaline waters.

The fish also prefer to remain in the sun for less than two hours rayons. This helps them grow more healthy growth.

Tank Setup

The setup of your tank for the tank setup for your Turquoise Rainbowfish requires special attention to provide the proper amount of care for these exotic fish. The rainbowfish melanotaenia Lacustris can live well when properly placed in a tank with the correct temperature and pH range.

This is how to ensure appropriate tank arrangement in the tank of your Turquoise Rainbow Fish.

  • To provide better care to the young rainbow fish melanotaenia Lacustris, a 30-gallon tank size is far more appropriate. To keep adult-sized schooling rainbowfish melanotaenia lapstris at your house, you will require a 60-gallon tank.
  • You must ensure that you are maintaining a stable and alkaline water balance in a communal tank. The pH range must be between 7-8.5.
  • The range of hardness for tank water should be in the interval from 8-25 dGH.
  • Make use of a small sand substrate that is darker in color for your fish to shine clearly in your tank.
  • Make use of a filter to ensure an even, yet gentle flow of water within the aquarium.
  • The majority of fish prefer moderate temperatures. So, it is important to keep temperatures within the range of 68-77 deg F.
  • The fish do not require high-intensity illumination in the aquarium of rainbow fish. You can use moderate to normal levels of light within the tank to take better care of your fish.
  • The fish are fond of living within dense vegetation. Therefore, you can add an appropriate amount of plants to your tank and leave some space to allow them to move around in peace.


Rainbowfish can be extremely hardy and illness isn’t often a problem when you have a properly maintained aquarium. But there’s absolutely no assurance that you will not be confronted with illness or health issues.

Keep in mind that any addition you make to your tank could bring diseases into your fish tank. Not just other fish, but substrate, plants, and even decorations could be a source of bacteria.

Be careful and make sure that you are thoroughly clean or quarantine any items you add to your existing tank so that you don’t cause a disturbance to the equilibrium.

The good thing about rainbow fish is that due to their resilience the onset of illness can be restricted to just one or a handful of fish if you tackle the problem early.

When you are keeping the more sensitive kinds of fish, it’s typical for all fish species to get sick before the first signs are noticed.

The most effective way to avoid disease is to provide your Rainbowfish with the best environment and provide them with an adequate diet.

The closer they are to their natural habitat, the less stress they will experience, making them healthier and happier. Fish that are stressed are more likely to contract the disease.

Turquoise Rainbowfish Care

The Lake Kutubu Rainbowfish is not easy to keep but, as with most rainbowfish, they are very sensitive to changes in the water’s condition.

They can be managed by a reliable filtration system, regular water changes, and testing. If the essential requirements of the fish are satisfied they can flourish.

If the tank is heavily stocked and full of water, it is essential to make frequent water changes. It is best to change 25-50% of tank water each week.

The process of getting their natural colors to show through is often difficult in aquariums, but it’s not difficult. In order to achieve colors that reach their fullest potential, the water has to be clean and there must be a suitable ratio of males and females.

They’re generally not fussy eaters and can eat many different food items, however, be cautious to not overfeed.

  • Aquarium Hardiness Moderately hardy
  • Aquarist Experience Level: Intermediate

The rainbowfish are generally far too hardy to be vulnerable to frequent illnesses. If they’re not taken care of properly they could contract frequent fish illnesses.

Incorporating any new fish species in aquarium plants, fish substrate, fish, or aquarium decor could result in the growth of bacteria within the tank.

The best thing concerning Turquoise Rainbowfish is that they are not likely to cause an outbreak of illnesses within the community tank. The disease they contract is usually only asymptomatic for one species.

In order to give them an extremely healthy and happy life in your tank, you must provide the freshwater fish with an adequate amount of healthy food. Make sure that the water is clean as well as stable to attain the right amount of immunity.

Food & Diet

Turquoise rainbow fish will easily accept high-quality dry food. It must also be supplied with lots of small, frozen, or live food items to ensure optimal health and color.

Melanotaenia lacustris generally are easy to feed in tanks. Rainbowfish typically have an omnivore diet which means that they are able to will eat all the essential foods for fish.

The freshwater rainbowfish, melanotaenia lacustris typically feed on small crustaceans, algae, and insects in their natural habitat.

While in captivity they’ll easily eat high-quality flake or pellet food.

To keep a variety of their diets, Turquoise Rainbowfish will also require live food elements to their food.

It is recommended to treat your rainbow fish melanotaenia with fish-based foods such as tubifex worms, brine shrimp, ghost shrimp, or bloodworms.

A portion of their diets could also include vegetables, providing them with better nutrition so they can produce brighter colors.

Typically, Turquoise Rainbowfish have smaller throats. Therefore, it is recommended to feed them in smaller amounts at a minimum of 2-3 times per day.

Be sure you give them food that they will be able to consume in no more than 5 minutes.

Tank Mates

Melanotaenia lacustris fish aren’t in any way aggressive If they are kept in tanks with compatible tank mates.

However, Lake Kutubu Rainbowfish can suddenly become aggressive and aggressive in the event that they discover that their fish mates in the aquarium aren’t very attractive or even suitable.

Melanotaenia lacustris is best kept in their own species or with other varieties of rainbowfish. You should add these rainbows of turquoise with fish of a similar temperament in size and temperament.

Turquoise Rainbowfish species are typically the shoaling species. So, you must select the right ratio to keep them all in your aquarium.

Additionally, you can keep a single breed school or two of the Blue Rainbows to see a significantly better improvement in their coloring.

If you have the collection comprising 5 Turquoise Rainbowfish together, it is recommended that you do not combine the genders. However, for schools of 6 fish, you could add 3 males as well as 3 females to your tank.

Additionally, if you wish to keep an entire collection comprising 8 Melanotaenia Lacustris It is suggested to keep 3 males along with 5 females in a single house.

In the event of an entire school of 10 specimens, you should have an equal amount of females and males in your tank.

If you’re considering adding these fish to a larger community tank, you could effortlessly house them alongside other tranquil tank friends.

However, do not place them in a room with aggressive or bigger ones.

As these fish grow larger and remain in an aquarium, they could quickly become a source of stress for their more vulnerable tank mates.

Here is an overview of the top compatible tank companions for Turquoise Rainbowfish.

  • Other rainbow fish
  • Danios
  • Barbs
  • Gobies
  • Characins
  • Corydoras


Breeding isn’t easy when you are young, when the fish is typically sold, however mature males are usually more vibrant, sport the arched back as described previously, and are usually more aggressive.

To ensure the successful breeding for the successful breeding Blue Rainbowfish, you need to create a suitable tank. The breeding tank for Lake Kutubu Turquoise Rainbowfish should be in moderately acidic water conditions.

In addition, to ensure a correct tank configuration, you have to make sure you’re making sure that you are adding sufficient filtration to the tank by using the help of a sponge filter.

You could consider keeping a spawning mop inside the tank or a fine-leaved plant to provide the Turquoise rainbowfish with enough space to lay eggs.

In order to achieve success in breeding the class comprised of Lake Kutubu Rainbowfish, 2 females and 3 males are good.

It is crucial to ensure that freshwater fish are properly conditioned in tanks by providing the right quantity of live foods as well as plant-based food.

The female Turquoise rainbowfish melanotaenia lcustris is more likely to show a desire to spawn, the males will display their vibrant colors and attract females to go towards the location of the spawning.

Once the female specimens have laid fertilized eggs, make sure to take out the spawning mops and plants to stop the fish that are parents from eating the eggs.

The fish will continue their spawning process for a few days. With time you’ll observe a decrease in the number of eggs being laid out by females.

A fry from this species typically hatches within a few days after egg-laying. In the first few days after their birth, you should feed your rainbowfish melanotaenia Lacustris fry a sufficient amount of infusoria, or liquid fry food to provide them with the best nutrition.

After a few days, you can give them small quantities of live food as well as crustaceans to provide better care.

While breeding, it’s important to remain vigilant and watchful to avoid crossbreeding. Most often, fish born of crossbreeding will lose color. So, it is recommended to create a completely different tank to breed rainbowfish melanotaenia lucustris.

Interesting Facts

There’s a wealth of information on Turquoise Rainbowfish, which you must be aware of prior to you bringing them into your home.

Here is the list of fantastic facts about them.

  • Melanotaenia lacustris are awe-inspiring because of the ability that allows them to change their colors during the course of the day. They are able to alter their hues in just a few seconds and display a range of shades during the course of the day mimicking the colors of a rainbow.
  • Their fins are known to be slightly blue in color with black edges once they are ready to spawn.
  • Two times a year, in Lake Kutubu, Melanotaenia lacustris decreases in number. The water is pumped up at the base of the lake which causes oxygen deficiency in the water, which kills an enormous amount of Blue Rainbowfish.
  • Due to the motion of water upwards, gill nets, logging and oil drilling, and outboard motors, In addition, the Lake Kutubu Rainbowfish is listed as a “Vulnerable” fish species in the IUCN Red List of Threatened species.
  • Adult male Turquoise Rainbowfish show a vibrant coloration and are more aggressive than females.
  • The Rainbowfish tend to be skilled jumpers and are always inclined to leap from the tank. Therefore, it is essential to attach a secure cover to the tank.


How Big Does A Turquoise Rainbowfish Get?

Adult size range: 4 – 4.9 inches (10 12.47 cm). 12.47 cm). Size of the average purchase: 2 inches (5 cm)

How Many Turquoise Rainbowfish Should Be Kept In A Single Tank?

Rainbowfish are shoalers and must be kept together in small groups in groups of 6 or more for the most effective impact.

Can Turquoise Rainbowfish Live With Angelfish?

Rainbow Kribensis are peaceful fish in the community that works well with Angelfish.

How Long Do Turquoise Rainbowfish Live?

The life span of the fish is 5 to 8 years. They could live a time that ranges from 5 to 8 years when kept in an aquarium that is well-maintained.


Turquoise Rainbowfish are pretty suitable to keep and care for in a tank for the community. They aren’t as hard to take care of as other species of rainbowfish.

However, they could be quite sensitive to changes in water. That’s why you should give the Turquoise Rainbowfish enhanced care, and ensure they have a clean and steady water condition.

In addition, to provide them with an appropriate level of treatment, you must possess a moderate or intermediate degree of expertise in this fish-keeping hobby.

Additionally, make sure you have a suitable level of filtration to ensure that the water stays clear. Additionally, ensure you’re housing them with the right tank companions to ensure they stay well and healthy for the duration of their stay with you.


Dibyajyoti Bordoloi is the creator and author of FishCampRehab.com, a third-generation experienced fish keeper and owner of a successful pet breeding farm. He is also a member of the Center for Wildlife Rehabilitation And Conservation (Assam), the Marine Aquarium Societies of North East India, and the Kaziranga Nature Conservancy of Assam.

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