Lake Kurumoi rainbowfish Care Guide: Diet, Tank Mates, Diseases, Breeding & More

Updated: November 23, 2022

The Lake Kurumoi rainbowfish is a beautiful and peaceful freshwater fish that is perfect for beginner aquarists.

This species is relatively easy to care for and can live in a wide range of water conditions. They are also very peaceful, which makes them a great addition to community tanks.

If you’re thinking about adding a Lake Kurumoi rainbowfish to your tank, this guide will teach you everything you need to know about their care.

Species overview

The Lake Kurumoi rainbowfish (Melanotaenia kurumoi) is a freshwater fish that is endemic to Lake Kurumoi in Papua New Guinea.

This fish is relatively small, only growing to be about 2.5 inches (6.4 cm) in length. They are silver in color with a horizontal stripe that extends from the gill cover to the base of the tail fin.

Lake Kurumoi rainbowfish are omnivorous and will eat a variety of different foods, including small insects, crustaceans, and plant matter.

In the wild, these fish are found in schools near the surface of the water. However, they can also be found in deeper waters (up to about 15 feet/4.6 meters).

These fish are not currently commercially bred, so allLake Kurumoi rainbowfish that are available for purchase are wild-caught.


Lake Kurumoi rainbowfish

The Lake Kurumoi rainbowfish is one of the more unique freshwater fish out there. They have a very elongated and thin body shape that makes them look quite sleek and streamline.

Their bodies are mostly silver in color with a few dark vertical stripes running down their sides. These stripes are usually broken up into a series of dots (especially near the tail).

The fins on this fish are also quite unique. The dorsal fin is tall and thin, starting about halfway back on their body. This fin gradually tapers off towards the end.

The anal fin is also tall and thin and starts a little bit closer to the head than the dorsal fin. This fin also tapers off towards the end.

The pectoral fins are small and thin, while the ventral fins are long and thin. The caudal fin is forked and symmetrical.


5-8 years

The lifespan of a Lake Kurumoi rainbowfish in captivity is 5-8 years. This is a long time for a fish, especially when compared to other pets like dogs and cats.

It’s important to note that the lifespan of a Lake Kurumoi rainbowfish can be significantly shortened if they’re not kept in optimal conditions. Things like poor water quality, stress, and a lack of food can all lead to an early death.


Lake Kurumoi rainbowfish are relatively small, only reaching about 2-3 inches in length at most. As a result, they don’t require a large tank to thrive and can even do well in something as small as a 10 gallon aquarium.


Tank Size

The recommended tank size for Lake Kurumoi rainbowfish is at least 55 gallons. This is assuming you want to keep them in a school of six or more fish.

Rainbowfish are active swimmers and need plenty of space to move around. They also prefer to be in groups, so the more fish you have the better.

Water Parameters

The ideal water parameters for Lake Kurumoi rainbowfish are fairly typical for tropical freshwater fish. They prefer warm water with a little bit of acidity.

The biggest thing to remember is to keep a close eye on your water quality. These fish are very sensitive to sudden changes in their environment. Sudden changes in temperature, pH, or hardness can be fatal.

You should test your water frequently and do partial water changes on a regular basis. This will help keep the water quality high and the stress levels low for your fish.

  • Water temperature: 76 to 82 degrees Fahrenheit
  • pH levels: 6.5 to 7.5
  • Water hardness: 4 to 8 dGH
  • Alkalinity Levels: 2-6 dKH

What To Put In Their Tank

When it comes to setting up the inside of their tank, these fish need a few specific things. First and foremost, they need a lot of hiding spots.

We recommend using a lot of plants (real or fake) and rocks to create these. You can even use driftwood if you have it. Just make sure that there are plenty of places for them to retreat to if they feel scared or threatened.

The second thing they need is a sandy substrate. These fish love to sift through the sand in search of food (and they’re really good at it too).

A third and final thing to consider is the water flow in their tank. Lake Kurumoi rainbowfish come from a river system with a moderate flow. You’ll want to replicate this in their aquarium as best as you can.

Common Diseases

There are a few diseases that you need to be aware of when keeping Lake Kurumoi rainbowfish. The most common one is ich, which is a parasite that can affect freshwater fish of all kinds.

This will present itself as white spots on the body of your fish. If left untreated, it can lead to serious health problems (even death).

Another disease to keep an eye out for is “Hole in the Head”. This is caused by poor water quality and the presence of activated carbon in the tank.

It will present itself as small pits or holes in the head of your fish. While it’s not usually fatal, it can cause some permanent scarring.

The best way to prevent these diseases is to simply maintain a clean and healthy environment for your fish. This means regular water changes, a good filtration system, and avoiding overfeeding.

If you do notice any signs of disease, the best thing to do is to consult a professional (veterinarian or fish store employee) and start treatment immediately.

Behavior & Temperament

Lake Kurumoi rainbowfish are peaceful fish that do well in community tanks. They are not very active fish and prefer to stay near the bottom of the tank.

They are not very aggressive, but they may nip at the fins of other fish. Lake Kurumoi rainbowfish are also known to jump out of the tank, so it is important to have a lid on your aquarium.

Lake Kurumoi rainbowfish are social fish and do best in groups. They are not aggressive towards other fish, but they may fight with each other if they are not in a group.

Tank Mates

Lake Kurumoi rainbowfish are peaceful community fish. In their natural habitat, they live in groups with other rainbows.

This is good news for aquarists who want to add them to their tank. It means that they’re likely to get along with other fish that occupy the same space in the water column.

You can also keep them with fish that prefer different levels of the tank. These fish are not known to be fin nippers, so you don’t have to worry about that either.

Some compatible tank mates for Lake Kurumoi rainbowfish include:

  • Neon Tetras
  • Cardinal Tetras
  • Congo Tetras
  • Bloodfin Tetras
  • Rummy Nose Tetras
  • Ghost Tetras
  • Black Neon Tetras
  • Chili Rasboras
  • Harlequin Rasboras


These fish are easy to breed as long as you provide them with the right habitat. For starters, you need a tank that’s at least 20 gallons. It should be set up with live plants and plenty of hiding places.

Lake Kurumoi rainbowfish are egg scatterers. The female will lay her eggs in the plants, and the male will fertilize them. Once that’s done, the parents will abandon the eggs.

You don’t have to do anything special to trigger spawning. Just make sure the fish are healthy and well-fed, and they should take care of the rest.

Eggs usually hatch in about a week. When they do, you can start feeding the fry live foods. Baby brine shrimp and daphnia are good options.

As they grow, you can transition them to flake food. Just make sure it’s finely crushed.


The Lake Kurumoi rainbowfish is a beautiful and unique freshwater fish that is perfect for the beginner aquarist. They are easy to care for and will do well in a community tank with other peaceful fish.

Their vibrant colors and active personality will add some life to your tank and they are sure to be a hit with everyone who sees them.

If you’re looking for a new fish to add to your tank, we highly recommend the Lake Kurumoi rainbowfish!