Red Rainbowfish

Red rainbowfish are freshwater fish that display some bright reds and stand out when kept in a shoal.

They are native to Western New Guinea and live in a variety of habitats including slow-moving streams, swamps, and even roadside ditches.

In this article, we’ll discuss everything you need to know about keeping red rainbow fish in your freshwater aquarium, including diet, tank mates, and more.

Red Rainbowfish Characteristics

Scientific Namethe Glossolepis incisus
Common NamesSalmon Red Rainbowfish, Red Irian Rainbowfish, Lake Sentani Rainbowfish, Irian Jaya Rainbowfish and New Guinea the Red Rainbowfish
SpeciesG. incisus
Lifespan6-8 years
SizeUp to 6 inches
Color Red
Care levelEasy
CompatibilityPeaceful community
Minimum Tank Size30 gallons
Tank SetupTropical freshwater with dense vegetation
Aquarist Experience LevelBeginner
Aquarium HardinessVery Hardy
Temperature70.0 to 79.0° F (21.1 to 26.1° C)
IUCN Red ListVU – Vulnerable – Human population around the lake are causing a decline in this fish population.

Red Rainbowfish Origin & Habitat

Weber discovered the new guinea red rainbowfish (Glossolepis incisus) in 1907.

They originate from the Lake Sentani region in the northeast of West Papua New Guinea (formerly Irian Jaya), near the city of Jayapura. 

This lake connects to the Pacific Ocean via tributary rivers called Jafuri and Tami.

These fish inhabit shallow parts of the lake, where there is a lot of dense vegetation for protection from bigger fish.

Red Rainbowfish Conservation Status

The IUCN Red List classifies the Red Rainbowfish as Vulnerable (VU).

This is because this species is restricted to Lake Sentani and it is highly sensitive to human population increase in this region.

What Are Red Rainbowfish Features?


The body of the red rainbowfish is slim and rounded, with the head jutting out in front and big black eyes.

In addition, they have two dorsal fins on top, one long anal fin beneath, and a forked caudal fin at the rear.


A healthy, adult male will be bright crimson all over his body and fins, with silver scales strewn throughout the center of his body.

However, the females and juveniles have brown bodies with grey fins.


Red rainbowfish species can grow up to 6 inches as adult fish.


These fish species can live up to 8 years in captivity if you take care of them properly.

Red Rainbowfish Availability

Salmon Red Rainbowfish is readily available in pet stores and online, and it costs approximately the same as other rainbow fish species.

Are Red Rainbowfish Hardy?

Red rainbowfish is hardy and can withstand a wide range of water conditions. This is one of the reasons why they are such a popular choice for beginner aquarists.

How to Care for Red Rainbowfish?

a.Water Requirements

1. Water Quality

Although the red rainbowfish is a hardy fish, it’s important to maintain good water quality in the aquarium.

Therefore, you should either do a 10% water change every week or a 25% change every two weeks. 

If you have a larger aquarium to care for, you may use a commercial water changer, gravel cleaner, and water conditioner.

This would keep the nitrate, nitrite, and ammonia at their lowest levels, which is essential for the health of your red rainbowfish.

2. Water Temperature

These fish come from warm areas that are close to the equator, so it is important to replicate warm water temperatures in their aquarium.

The ideal water temperature for red rainbowfish is between 70 and 79 degrees Fahrenheit.

To avoid any sudden changes in temperature, you should use an aquarium heater and thermometer.

3. pH Level

Red rainbows inhabit highly alkaline lakes and streams, so they need a high pH level in their aquarium.

The ideal pH level for these fish is between 7.6 and 8.2

You can use a water testing kit to check the levels in your aquarium and make sure they are within the correct range.

4. Water Hardness

Red rainbowfish prefer water hardness levels between 9 and 19 dGH.

b.Tank Setup

1. Tank Size

Red rainbowfish are active fish that swim in schools of at least six fish.

Also, they are top dwellers that like to swim in the upper levels of the aquarium, so you need to provide them with plenty of vertical space.

Therefore, you should provide them with an elongated tank that is at least 30 gallons in size. 

However, if you plan on keeping a large school of these fish, you should consider a tank that is 60 gallons or larger.

2. Decorations

These fish feel most comfortable in a densely planted aquarium with plenty of hiding places.

You can add Java ferns, hornwort, and Anubias to the tank. Also, you can use driftwood and pebbles to create a more naturalistic setting.

Furthermore, rocks and bogwood are suitable decorations for imitating the look of Lake Sentani.

3. Tank Lid

Red rainbowfish jump out of the tank when they feel threatened, so it’s important to cover the tank with a tight lid.

4. Lighting

Red rainbows prefer moderate lighting that simulates their natural habitat. 

You can use LED aquarium lights or fluorescent bulbs to provide the appropriate level of lighting.

5. Filteration System

A high-quality filter is essential for keeping the water clean and maintaining good water quality.

Since they require rapid water movement, you’ll need strong powerheads to keep up with the tank size.

To achieve that, you can install a canister filter.

Red Rainbowfish Compatibility

Rainbowfish are one of the most peaceful fish in the aquarium. 

They get along with a variety of tankmates, particularly those similar in size and temperament.

However, they start to fight when the spawning time arrives as they chase one another without causing harm.

The table below lists some of the best tankmates for red rainbowfish:

Type of fishStatus
Same species – conspecifics (Turquoise, Madagascar & Celebes)Groups of 6 or more are preferred
Peaceful fishSafe – Similar size tank mates are best, as these larger active rainbowfish can make smaller fish nervous.
Large Semi-AggressiveThreat
Large Aggressive, PredatoryThreat
Slow Swimmers & EatersMonitor – Rainbowfish are active fish that can make slower fish nervous and stressed.
Shrimps, Crabs, SnailsSafe – not aggressive
PlantsSafe – Plants need to be sturdy enough to stay rooted and recover from any browsing.

Although red rainbows are schooling fish that enjoy being in large groups, you should take into account the male-to-female ratio in your aquarium.

The table below lists the proper ratio of males to females:

Number of fishMale to female ratio
5 rainbowfishDo not mix sexes
6 rainbowfish3 males + 3 females
7 rainbowfish3 males + 4 females
8 rainbowfish3 males + 5 females
9 rainbowfish4 males + 5 females
10 rainbowfish5 males + 5 females

Red Rainbowfish Diet

Red rainbowfish are omnivores that eat a variety of foods in their natural habitat. 

In the wild, red rainbows eat insects, mosquito larvae that fall into the water as well as floating vegetation.

In captivity, you should give them a well-balanced diet that consists of frozen foods and very small live foods.

Some of the best foods for red rainbows include:

  • Brine shrimp
  • Bloodworms
  • Daphnia
  • Tubifex worms
  • Pellets
  • Flakes
  • Granules
  • Water fleas
  • Little treats of ants

When it comes to feeding frequency, you should feed your fish twice a day in small portions that they will be able to consume within 5 minutes.

Red Rainbowfish Breeding

Red rainbowfish are quite easy to breed in the aquarium. However, you need to make sure that the conditions in the tank are ideal for spawning.

Here are some of the things you need to do to prepare your tank for breeding rainbowfish:

  • Provide a separate breeding tank
  • Decorate the breeding tank with fine-leaved plants or spawning mops
  • Maintain the water temperature at around 79 F
  • Maintain high water quality
  • Add a high-quality sponge filter
  • Introduce a healthy pair of adult red rainbowfish
  • Offer them high-quality food more than usual

After you’ve prepared the breeding tank, the male and female fish will start to chase each other around the tank until they find a suitable spot for spawning.

When they’re ready to spawn, the female fish will lay their eggs on the plants or mops in the tank. 

After she lays the eggs, the male fish will fertilize them.

After fertilizing, you should remove the parents from the breeding tank because they might eat the eggs.

Within 7-8 days, the eggs will hatch and the fry will start to swim around the tank.

During this time, you should start feeding them tiny meals like infusoria for the first week of life, until they are big enough to eat brine shrimp nauplii.

Last Words

Red rainbowfish are one of the most beautiful and peaceful fish that you can keep in your aquarium.

If you’re thinking about adding red rainbows to your aquarium, make sure to provide them with the proper conditions and diet so they can thrive.

We hope you’ve found this article helpful. If you have any questions or comments, please feel free to leave them below.

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