Interesting Facts About Rainbowfish

Have you ever wondered what those little colorful freshwater fish called that you see swimming around in pet stores? They’re called rainbow fish!

There are over 50 different species of rainbow fish with fascinating facts to learn about.

In this article, we’ll take a look at some of the most rainbow fish facts, including their natural habitat, diet, and lifespan.

1. Rainbowfish Origin & Habitat

Rainbowfish come from North-eastern Australia, including the fresh and brackish streams of Queensland.

In addition, they live in Raja Ampat Islands in Indonesia, the Cenderawasih Bay Islands, and New Guinea.

These freshwater fish inhabit slow-flowing freshwater rivers, wetlands, billabongs, rivers, drains, creeks, ponds, and reservoirs.

However, they are stated to be endangered species in their natural habitats due to the introduction of exotic species, water pollution, and habitat destruction.

2. Rainbowfish Belong to Melanotaeniidae Family

The name “Melano” is derived from the Ancient Greek words “melano” (meaning black) and “taenia” (meaning ribbon).

This is about the black bands that are present on the bodies of many of the fish within this genus.

3. Rainbowfish Do Well With Other Peaceful Tank Mates

Rainbowfish are peaceful fish that go along with other peaceful tank mates as long as they are of a similar size or smaller.

Some good tank mates for rainbowfish include:

• Mollies
• Guppies
• Swordtails
• Gourami
• Barb
• Tetra
• Rasboras
• Kribensis Cichlids and other non-aggressive species of cichlids
• Otocinclus catfish
• Corydoras catfish

4. Rainbowfish Are Schooling Fish

Rainbowfish are schooling fish that need at least 6 tank mates to feel comfortable and secure.

When kept in a group, rainbowfish are very active and love to swim around the tank exploring their surroundings.

Otherwise, they may become shy and reclusive. This can lead to health problems such as stress and a weakened immune system.

5. Rainbowfish Show Aggression During Spawning Time 

During the breeding season, male rainbowfish will try their hard to court the female by displaying their bright colors and swimming in front of it.

If there are too many males, they will become aggressive towards each other and may even kill one another.

Therefore, you should maintain the proper ratio of male to female rainbowfish (2 to 3) in your tank.

6. Rainbowfish Are Aggressive in an Overstocked Aquarium

Rainbowfish prefer to swim about and require a lot of areas to feel comfortable. 

If they are restricted, they can become very aggressive behavior.

This behavior may range from bullying other species to flashing and can even lead to biting and fin nipping.

Therefore, it is important to provide them with plenty of space (at least 20 gallons per fish).

7. Rainbowfish Have Unique Appearance

Rainbowfish are characterized by the large teeth on their upper jaw.

Their body is compressed and the two dorsal fins are separated with only a small gap between them.

Also, the first dorsal fin of some species has 3–7 spines, whereas the second has 6–22 rays, with the first ray being a strong spine in some species, and the anal fin has 10–30 rays.

In addition, they have comparatively large scales, which number 28–60 in their lateral series.

Furthermore, the pelvic fins are connected to the fish’s abdomen via a membrane that runs down the length of the innermost ray.

8. Rainbowfish Are Medium-Sized Species

Most rainbowfish species are less than 4.7 in (12 cm) in length.

However, some species are only 2.4 inches (6 cm) long, while Melanotaenia vanheurni species can grow up to 7.9 inches (20 cm).

9. Rainbowfish Develop More Colors As They Age

Just like a high-quality wine, rainbowfish get better with age. Juvenile rainbowfish is a silvery-white color, but their colors will become more vibrant as they grow older.

10. Rainbowfish Males Are More Colorful Than Females

Rainbowfish are sexually dimorphic, with males being the more colorful sex and displaying an elongated fin ray.

On the other hand, females have shorter fins and less bright colors than males.

11. Rainbowfish Have an Average Lifespan of 5 Years

If we look at the average frequencies, rainbowfish have a lifespan of approximately 5 years.

However, the lifespan of your aquarium may differ by four to eight years depending on the care you provide them.

12. Rainbowfish Are Jumpers

Rainbowfish will leap out of the tank if they feel threatened or if they are not comfortable in their surroundings.

Therefore, you should keep a tight-fitting lid on your aquarium to prevent them from jumping out.

13. Rainbowfish Are Hardy

Rainbowfish are very hardy and can adapt to a wide range of water conditions which makes them ideal for beginner aquarists.

However, if their water quality isn’t properly maintained, they can get diseases just like any other fish.

14. There Are Over 50 Species of Rainbowfish

There are a variety of species of rainbowfish that come in all different shapes, sizes, and colors.

Some of the more popular species include:

• threadfin rainbowfish (featherfin rainbowfish)
• Boeseman’s rainbowfish
• Neon rainbowfish
• Forktail rainbowfish (blue eye forktail rainbowfish) (furcata rainbowfish)
• Red rainbowfish
• Salmon red rainbowfish
• Red neon blue eye rainbowfish (pseudomugil rainbowfish)
• Neon dwarf rainbowfish
• Celebes rainbowfish
• Lake kutubu rainbowfish
• Spotted blue eye rainbowfish (Gertrude rainbowfish)
• Australian rainbowfish
• Turquoise rainbowfish
• Axelrod’s rainbowfish
• Madagascar rainbowfish
• Yellow rainbowfish
• Kamaka rainbowfish
• Lake tebera rainbowfish
• Blue rainbowfish
• Goyder river rainbowfish
• Trifasciata rainbowfish (banded rainbowfish)
• Pygmy rainbowfish
• Pacific blue eye rainbowfish
• Allen’s rainbowfish
• Tami River rainbowfish
• Honey blue eye rainbowfish
• Parkinsoni rainbowfish

15. Rainbowfish Prefer Water Temperature Between 68-75 Degrees F

These fish prefer warmer water that is between 68-75 degrees Fahrenheit.

Similarly, raising the temperature to 83 degrees F (28 degrees Celsius) will trigger spawning.

To maintain these temperatures, you can use an aquarium heater, and to avoid any fluctuations, you should keep the heater on a thermometer-controlled outlet.

16. Rainbowfish Require a pH Between 6 and 9

In general, a Rainbowfish can live in a pH range of 6 to 9, but it does not imply that any of the boundaries are desirable.

If the pH is less than 6 or greater than 9, one of the first indications is stunted growth.

Moreover, when the pH drops below 4 or goes up above 10 in the fish tank, your pet fish will die.

17. Rainbowfish Are Omnivorous Fish

Rainbowfish are omnivores, which means they will eat both meat and plants.

In the wild, rainbowfish eat mosquito larvae, small invertebrates, insect larvae, small crustaceans, and zooplankton.

You can replicate their diet in the aquarium by feeding them live, frozen, or freeze-dried foods as well as flakes or pellets that are designed for omnivorous fish.

It’s also a good idea to supplement their diet with fresh vegetables such as zucchini, lettuce, and peas.

18. Rainbowfish Are Egg Layers

Rainbow fish is an egg-laying species that typically spawn in groups. The female will lay her eggs on plants, and the male will fertilize them.

Last Words

Rainbow fish are peaceful species that make a great addition to any community aquarium.

They are relatively easy to care for as long as you provide them with the proper diet and water conditions.

With over 50 different types of rainbowfish, there is sure to be one that is perfect for your aquarium!

Do you have any rainbow fish in your aquarium? Let us know in the comments below!