Fun Lake Wanam Rainbowfish Facts For Kids

Ritwik Bhuyan
Oct 20, 2022 By Ritwik Bhuyan
Originally Published on Aug 17, 2021
Edited by Katherine Cook
Fact-checked by Sakshi Raturi
Lake Wanam rainbowfish facts are about this endemic species found in Lake Wanam.
Age: 3-18
Read time: 7.1 Min

The Lake Wanam rainbowfish (Glossolepis wanamensis) is a species of rainbowfish endemic to Lake Wanam in Papua New Guinea. This lake is situated above the Markham River Valley. Although this fish is popular in aquarium habitats and is caught a lot, the small lake houses fewer specimens which have led to the Critically Endangered status of this species. This fish species has now virtually disappeared from its natural distribution in Lake Wanam. The fish species has been found in shallow, clear water around surface vegetation on the lake. However, for quite some time now, this species has not been spotted in their natural habitat. Also, the introduction of introduced species, Tilapia, has caused this group of fish to disappear.

According to history, the fish was first discovered by Allen and Kailola in 1979. Before this, live specimens were collected in 1978 by Allen and Crockford. The species is also known by the name emerald rainbowfish because of the emerald-green coloration in males. This species has now undergone captive breeding and the population is slightly increasing.

Male Lake Wanam rainbowfish color is usually emerald green, however, in females, the color is dull green. The description to spot a breeding rainbowfish is easy as because during breeding, a bright yellow stripe is seen from the nose to the first of the dorsal fins. The fish can have food ranging from protein-rich brine shrimp, flakes, live food, frozen food, blood worms, mosquito larvae, daphnia, and sometimes other insects too.

For more relatable content, check out these meagre fish facts and rockfish fun facts for kids.

Lake Wanam Rainbowfish Interesting Facts

What type of animal is a Lake Wanam rainbowfish?

The Lake Wanam rainbowfish is a fish found in Lake Wanam in Papua New Guinea.  

What class of animal does a Lake Wanam rainbowfish belong to?

The Lake Wanam rainbowfish (Glossolepis wanamensis) belongs to the class of Actinopterygii in the kingdom of Animalia.

How many Lake Wanam rainbowfish are there in the world?

The population of the Lake Wanam rainbowfish is not known. The distribution range of the fish is very small as it is endemic to a single lake with an area of occurrence of just only 1.5 sq mi (4 sq km). These fishes are not even seen in this habitat nowadays.

However, the captive population of this fish still exists and is thriving in aquarium habitats all around the world. This is a peaceful rainbowfish and is mostly wanted by people who keep aquariums as a hobby.

Where does a Lake Wanam rainbowfish live?

The Lake Wanam rainbowfish (Glossolepis wanamensis) is endemic to Lake Wanam near Lae in Papua New Guinea. This freshwater lake is situated in the vicinity of Mount Ngaroneno, at the southern end of the lower Markham Valley. This valley is near Oomsis, Morobe Province which is around 15.5 mi (25 km) inland from the Huon Gulf.

What is a Lake Wanam rainbowfish's habitat?

The lake where the group of these fishes is known to be found is only 1.2-1.8 mi (2-3 km) in diameter. The area of occurrence is really small and this has led to a decrease in numbers for this species. The fish is found in the shallow, clear, lighted water areas near sub-surface vegetation, submerged logs, near reeds, and other shoreline vegetation. The lake where the specimens have been collected had a temperature of 82.4 F (28 C) and ph 7.0-7.8. The same conditions are needed to be replicated in tanks for the maximum life of these fishes.

Who do Lake Wanam rainbowfish live with?

This is a peaceful schooling fish that can accommodate other rainbowfishes with them in the aquarium tank. They can also find themselves with other species of fish in the aquarium tank. Schools can be of five or more fish, and every male should be paired with two or three females in the tanks.

How long does a Lake Wanam rainbowfish live?

The lifespan of this fish is considered to be between five to eight years.

How do they reproduce?

The number of Lake Wanam rainbowfish eggs is not known, however breeding and spawning are quite easy. For the eggs, a spawning mop should be added to the breeding aquarium tank. However, separate tanks should be provided as the parents might try to eat the eggs after spawning. After the fry is born in the separate tank, they can be fed infusoria or vinegar eels. The fry will be able to have foods like baby brine shrimps later.

These fish need to kept in a clean tank of around 20 gal (7.7 L) with water of a warm temperature. Fry need a lot of room to grow, so the aquarium size should be larger enough to allow them to grow properly. The eggs usually stick to the spawning mop. Many people with this hobby love breeding these fishes as they can share the fish with others.

The Lake Wanam rainbowfish female lays the eggs on the spawn and then the owners separate them as there have been cases of adults using the eggs and fry as foods.

What is their conservation status?

The conservation status of the Lake Wanam rainbowfish (Glossolepis wanamensis) is categorized as Critically Endangered by the IUCN Red List. The small range and introduction of a non-native species in the water have caused the decline in the numbers of Lake Wanam rainbowfish. The rate of extinction for Lake Wanam rainbowfish is now quite fast and rarely any fish can be seen in the natural lake habitats of Papua New Guinea.

The aquarium hobby is one of the fastest-growing in the world and this is probably saving this species for the time being. People love keeping this fish on display in their homes.

Lake Wanam Rainbowfish Fun Facts

What do Lake Wanam rainbowfish look like?

The Lake Wanam rainbowfish (Glossolepis wanamensis) is known to change the color of its body with respect to foods, temperature of the water, and water hardness. The posterior side of the male is more green with some blue hue and the anterior part is of dusky orange coloration. The back is metallic green. The colors of the long dorsal and anal fins change from specimen to specimen. Fins can sometimes be fully black.

The Lake Wanam rainbowfish male is a little longer in length than the female that is is deeper bodied and more colorful. The males have an extended anal fin and first dorsal fins. The fry is fully black and groups sometimes appear to look like spillage.

Red Rainbowfish

* Please note this is an image of a red rainbowfish, not a Lake Wanam rainbowfish. If you have an image of a Lake Wanam rainbowfish, let us know at

How cute are they?

Groups are kept as display in aquariums for their magnificent coloration and peaceful nature. These fishes are hardy and need moderate care. They are considered quite beautiful.

How do they communicate?

Fishes usually communicate by chemicals and bodily movement.

How big is a Lake Wanam rainbowfish?

Length description shows that males are around 3.93 in (10 cm) long, while females are 3.15 in (8 cm) long. The body depth is 1.57-1.96 in (4-5 cm).

How fast can a Lake Wanam rainbowfish swim?

The speed of a Lake Wanam rainbowfish is not known.

How much does a Lake Wanam rainbowfish weigh?

The weight of a Lake Wanam rainbowfish is not known.

What are the male and female names of the species?

Males and females of  Lake Wanam rainbowfish (Glossolepis wanamensis) are not given different names.

What would you call a baby Lake Wanam rainbowfish?

A Lake Wanam rainbowfish baby is called fry.

What do they eat?

Their favorite foods include insects, quality flakes, brine shrimp, and blood worms in the aquarium. The Lake Wanam rainbowfish (Glossolepis wanamensis) may even feed on snails sometimes.

Predators of the members of the family Melanotaeniidae include freshwater snappers, grunters, and cardinal fishes.

Are they dangerous?

The fish is not considered dangerous and is quite peaceful.

Would they make a good pet?

The fish is kept as a pet all over the world. Water condition, hardness, temperature, tank mates, and diet all matters and should be of the highest standard to get maximum results. The Lake Wanam rainbowfish temperature requirements are warm and should be around 80.6 F (27 C).

The rainbow fish species can be easily kept in an aquarium with other similarly sized rainbowfishes, danios, characins, barbs, and catfishes.

Did you know...

Males can be identified in the water by their emerald green coloration and this is much duller in females. This difference in coloration can be easily spotted in clear water.

What role do Lake Wanam rainbowfish play in the ecosystem?

The fish helps preserve the lake's health by eating insects and organisms in the water. This fish also helps to keep the water body clean.

Why are Lake Wanam rainbowfish endangered?

Due to the small range of habitat and the introduction of a non-native species in the water of the lake, Lake Wanam rainbowfish are now Critically Endangered.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! For more relatable content, check out these ladyfish facts and black ghost knifefish facts for kids.

You can even occupy yourself at home by coloring in one of our free printable celebes rainbowfish coloring pages.

Lake Wanam Rainbowfish Facts

What Did They Prey On?

Brine shrimp, flakes, live food, frozen foods, blood worm, mosquito larvae, and daphnia

What Type of Animal were they?


Average Litter Size?


How Much Did They Weigh?


What habitat Do they Live In?

shallow, clear, sand unlit water

Where Do They Live?

lake wanam in papua new guinea

How Long Were They?

3.15-3.93 in (8-10 cm)

How Tall Were They?

Body length: 1.57-1.96 in (4-5 cm)







Scientific Name

Glossolepis wanamensis

What Do They Look Like?

Emerald-green body, yellow-orange lines on the abdomen, and dark green unpaired fins

Skin Type

Wet and slimy scales

What Are Their Main Threats?

habitat loss and small range

What is their Conservation Status?

Critically Endangered
We Want Your Photos!
We Want Your Photos!

We Want Your Photos!

Do you have a photo you are happy to share that would improve this article?
Email your photos

More for You

See All

Written by Ritwik Bhuyan

Bachelor of Arts specializing in English

Ritwik Bhuyan picture

Ritwik BhuyanBachelor of Arts specializing in English

A skilled content writer, Ritwik holds a Bachelor's degree in English from Delhi University. He has refined his writing abilities through his past experience at PenVelope and his current role at Kidadl. In addition to his proficiency in writing, Ritwik has pursued his passion for flying by achieving CPL training and becoming a licensed commercial pilot. This diverse skill set highlights his commitment to exploring multiple fields. Ritwik's experience in the aviation industry has provided him with a unique perspective and attention to detail, which he brings to his writing.

Read full bio >
Read the DisclaimerFact Correction