Rainbow Fish – The Colorful Sweetheart!


Rainbow Fish – The Colorful Sweetheart! Rainbow Fish are a small, colorful fish with over 50 species. These beautiful fish can change their color and pattern for camouflage and for communicating with other fish of their own kind.

They typically live in freshwater environments. Their colors range from pale silver, through rich blues and greens, to bright oranges and reds. They live in rivers and streams in fast-flowing, crystal-clear water that is low in sediment content.

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Rainbow Fish - The Colorful Sweetheart! 17 Pointers

Basic Facts

Black-banded Rainbowfish is a member of the Melanotaeniidae family, which consists of some of the most beautiful fish in the aquarium.

They are characterized by their bright colors, metallic shine and wide tail fin.

They are commonly found in Australia, New Guinea and Indonesia and come in a rainbow of colors, including white, yellow and black.

Some species are endemic to Java, Bali and Sulawesi in Indonesia and Madagascar. The technical name is Melanotaenia Boesemani.

Melano-taenia are the Greek words for “black and banded”. These fish have black bands from which they derive their name.


Rainbowfish are known for their bright and colorful scales and are native to the freshwaters of Australia, Indonesia, New Guinea and Madagascar.

These fish have two dorsal fins which are separated but with a very slight gap between them. Rainbow fish have a compressed body and the distal premaxillary teeth are enlarged.

The Rainbow Fish has a pelvic fin located near the tail fin. It is attached to the abdomen by a membrane.

The Rainbow Fish can grow up to 4.7 in long and generally live for 5–8 years, although some have been known to live longer in captivity.


The Rainbow fish is active and peaceful, but two males may fight during breeding. If the tank is too crowded, they will become stressed and their colors will fade.

Rainbow fish prefer a community of similarly aged and sized fish. They get along with other small fish but may pick on species that appear fearful or weak.

In the wild, they are found in schools near aquatic vegetation, which gives them places to hide if they are startled.

The Rainbow Fish is a very social fish, and it will do best when placed in a school of six or more individuals. It’s best to keep multiple Rainbow Fish together, as they are highly compatible with one another.

Gender Differences

Rainbow fish exhibit conspicuous sexual dimorphism: males are brightly colored, and females are more subdued (often brownish or grey).

Males have an elongated median fin ray, while females do not. Females also have shorter fins. Females are smaller than males.

The male fish has will have a greater area of iridescence in comparison to the female.

Water & Tank Requirements

The ideal environment for rainbow fish is an alkaline water with a pH of 7.0 to 8.0. The total alkalinity must be between 5° to 20° and a dKH (dissolved potassium hydrogen carbonate) of 90 ppm to 360 ppm.

The temperature range should be 74°to 78°F. Hardness between 10–20 dGH is recommended. A 10% water exchange every week.

A good filtration system is also essential. They need low lighting and a dark hiding spot in their tank to prevent them from getting stressed.

The Rainbow Fish is not a very difficult fish to care for and will thrive in minimum 15–30 gallon tanks. The tank should have plenty of swimming space as well as hiding places for the fish to rest.

Tank Mates

The Rainbow Fish is a peaceful, schooling fish that does well in a small school of 6 or more. They should not be kept with larger fish that may eat them and they also need to avoid fish that are too aggressive especially cichlids.

This makes them well suited to a large community tank with other small fish such as tetras, barbs, rasboras, danios and catfish. They will also get along well with non-aggressive cichlids like Kribensis. Also ensure you avoid fin nipping fish.

However, if you’re looking for a community tank setup, you should avoid putting your rainbowfish in tanks with timid or very slow-moving species since they can be aggressive shy or slow-moving fish.


Rainbow fish are easy to care for and a good choice for beginners. They are hardy and survive in tanks with low water quality.

They need plenty of water movement, so include a filter or powerhead in the tank. Floating plants help dim the light and provide a shaded area for them to retreat to when they want to rest, making them happy fish!

While they are a small fish, they typically require moderate lighting for a couple of hours. This enhances their color.

Small-leaved plants such as java moss and java fern are ideal because they provide more swimming space.

A combination of hardy freshwater plants will create a natural environment for your rainbow fish.

Rainbowfish are a hardy, colorful fish that can thrive in the right conditions of water and food. Water fluctuations are a big no. Watch out for their susceptibilities to Fin Rot, Ich and Velvet Disease.

Rainbowfish are more at risk of developing these diseases because they have less slime coating than other varieties of Aquarium fishes.

Feed regularly, monitor water quality and look out for any signs of stress or damage to your fish.

Rainbowfish are sensitive to nitrate and ammonia, so avoid foods that sink to the bottom of the tank and remove any uneaten food as soon as possible.


The Rainbow fish is an omnivore, meaning that it eats both plants and animals. It is a scavenger; it will eat almost anything organic including algae, crustaceans and larvae.

To maintain a balanced diet, the Rainbow fish should be fed a variety of foods such as krill, flake food or pellets with vegetables & fruit (carrot or peas) at least once per week to ensure that they are receiving all the nutrients they need to stay healthy.

Rainbow Fish need to be fed regularly in controlled portions. The overfeeding of these fish can lead to health problems, so be sure not to overfeed your fish.


Rainbow fish can be found in locations with tropical climates. They spawn all year and lay a large number of eggs, which they then attach to vegetation. A temperature increase encourages spawning.

The eggs hatch within 7-18 days depending on the species, temperature and location. There is no parental care after laying.

So, separating the pair and moving them to another tank is a good thing to do. This is so because, you can move the parents back once the eggs are laid.

Few Facts

The Rainbowfish is a popular aquarium fish, which is sold as a tropical fish. Rainbowfish are made up of two main groups.

The first group contains the Families Melanotaeniidae and Bedotiidae, which include larger, active fish . The second group includes the Families Pseudomugilidae and Telmatherinidae.

The Family Pseudomugilidae includes smaller docile fish that are less likely to venture too far from their habitat.

The family Telmatherinidae includes a lone species, Marosatherina ladegesi, the Celebes Rainbow. Look at your fish and we think you’ll agree that its almost too gorgeous to be real!

Rainbow Fish. Facts. color enhances with age. So, as they grow, they get more and more beautiful & colorful!

Rainbowfish are known for their voracious appetites; they will eat anything that fits in their mouths! They enjoy live foods such as brine shrimp and mosquito larvae but also readily accept flakes or flake food.


Why do we love aquariums? Because they’re colorful, relaxing and inspiring. Rainbow fish are no exception to this rule. These little fishes can not only be fun to watch, but they are also a big asset to your tropical aquarium. They are relatively easy to care for and are a colorful addition both to the tank and to the human eye!

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Wini, an animal and aquarium owner for 25+ years, has owned various dog breeds, participated in dog shows, and bred show quality puppies. She has also owned and imported champion quality cats, adopted shelter cats, and sponsors cats in shelters. With childhood experience in freshwater aquariums, she currently has four large aquariums. Wini is an attorney, artist, and blog writer who specializes in rendering legal advice to NGOs and pet centers. Her blog covers pet-related topics like grooming, training, nutrition, health, behavior, fish breed profiles, and more. She aims to provide valuable information to help readers better care for and understand their pets.