Fun Sundadanio Axelrodi Facts For Kids

Ritwik Bhuyan
Oct 20, 2022 By Ritwik Bhuyan
Originally Published on Aug 06, 2021
Edited by Luca Demetriou
Fact-checked by Sonali Rawat
Discover Sundadanio axelrodi facts like their different color morphs, depending on the locations they are found

The species called Axelrod's rasbora (Sundadanio axelrodi) was previously named Rasbora axelrodi. A new genus was created called Sundadanio.

These rasboras are known by many different names like - blue neon rasbora and neon blue rasbora. The rasboras are a part of the family Cyprinidae and are danionins. The origin of this fish is found to be from blackwater pools and streams.

So, while keeping them in an aquarium, it is very much necessary to be wary of the condition of the water. The rasbora fish is peaceful, active, and a species of good-looking schooling fish, which is a great addition to any planted aquarium tank for your homes.

This neon-blue fish is named after a pet book publisher Herbert R. Axelrod. It would be best if you always keep this gorgeous little fish species with other species of fish of the same size and the same personality.

The fish is quite hardy but needs a lot of care to be kept as a pet. Read more about these down below.

Fishes live in most of the water in the world and we don't even know the existence of many species living in the deep corners of the sea. Read some more fun facts on the sockeye salmon and the parrot fish. 

Sundadanio Axelrodi Interesting Facts

What type of animal is a Sundadanio axelrodi?

This fish is a danionin (Danios, Devarios, Rasboras) and a part of a very popular group of aquarium fishes.

What class of animal does a Sundadanio axelrodi belong to?

Neon blue rasbora (Sundadanio axelrodi 'blue') belongs to the class of Actinopterygii of the family Cyprinidae in the kingdom of Animalia. They were earlier known as rasbora axelrodi, but later found that they are closely related to a danio instead, but not close enough to be included in the same genus.

How many Sundadanio axelrodis are there in the world?

The population of the neon blue rasbora is unknown.

Where does a Sundadanio axelrodi live?

The Axelrod's rasbora is found mostly in blackwater pools and streams associated with ancient forest peat swamps. To take proper Sundadanio axelrodi care in the tank, the water should be stained dark-colored brown and the substrate scattered with fallen leaves, twigs, and branches. The water hardness should be made negligible, and the pH needs to be less than five.

What is a Sundadanio axelrodi's habitat?

The Sundadario axelrodi is native to the Greater Sunda Islands of Borneo and Sumatra. They are also found in Riau Archipelago and Bangka Island off the east coast of Sumatra.

Who do Sundadanio axelrodis live with?

This fish species are always found in schools, and they like to be a part of large schools. In an aquarium of 10 gallons, six or more fishes of the same size should be kept.

Depending on size, the rasboras can be teamed with various other small schooling fishes like small tetras (like Green Neon Tetra), gouramis, and many small danios.

How long does a Sundadanio axelrodi live?

This species of neon-blue fish are known to live for two to five years if given proper care and the best living conditions, which include conditions like temperature, pH, and the quality of the water.

How do they reproduce?

These fish are not seen breeding in the tanks as they do not like fluctuating water conditions. There are some cases, however, when the fish has been bred in captivity. The conditions of lighting and water should be optimum for this to happen.

A heavily planted and well-established aquarium is required. The fish should have a diet with plenty of live and frozen foods in this duration. If the cover and microfauna, along with proper water conditions, are met, the spawn should appear.

Reports of reproduction in nature or the number of eggs laid are not known.

What is their conservation status?

The conservation status of the neon blue rasbora (Sundadanio axelrodi 'blue') is categorized as Vulnerable by the IUCN Red List. The habitats are degrading, and due to the small distribution of the fish, the population is decreasing rapidly.

The precious biotopes in southeast Asia are under threat from rubber and palm oil plantations, building developments, and many other activities by humans.

Sundadanio Axelrodi Fun Facts

What do Sundadanio axelrodis look like?

Neon blue rasbora (Sundadanio axelrodi 'blue') are found in various color morphs, but the differences are very limited and slight. It depends on the places that they are found.

The fish found south and east of Sarawak state in Borneo of Malaysia are usually colored blue or green. The fish from the west are red or orange in color. The neon blue coloration is the most popular variant.

Adult males are slimmer and more colorful than adult females. In some morphs, a dark coloration is found in the anterior portion of the anal fin of the males. In other cases, the anal fin is generally red. The females, however, have a colorless anal fin.

Read amazing facts about the Sundadanio axelrodis.

*Please note: This image is of clown rasbora, a member of the same species as the neon blue rasbora. If you have an image of the neon blue rasbora, email us at

How cute are they?

The fish with the small size and beautifully colored body make for a beautiful aquarium.

How do they communicate?

Males produce audible croaking/chirruping sounds when stressed or taken out of the water. The sound is also heard when they fight with other fishes in the tank.

How big is a Sundadanio axelrodi?

The length of the fish range from 0.75-1.25 in (1.9-3.1 cm).

One of the popular micro fish, the white cloud mountain minnow, is sized 1-1.5 in (2.5-3.8 cm).

How fast can a Sundadanio axelrodi swim?

The swimming speed of the fish is unknown.

How much does a Sundadanio axelrodi weigh?

The weight of this fish is not known.

What are their male and female names of the species?

Males and females of the species are not given different names. They are known collectively as neon Axelrod's rasbora (Sundadanio axelrodi).

What would you call a baby Sundadanio axelrodi?

The babies are called spawns.

What do they eat?

The neon blue Rasbora (Sundadanio axelrodi 'blue') are carnivores and have a diet of tiny aquatic crustaceans, worms, insect larvae, and other zooplankton. They feed on small live or frozen foods such as daphnia, nauplii, artemia, and bloodworms in captivity. This helps them develop better coloration and condition.

Are they dangerous?

They are not dangerous.

Would they make a good pet?

The best Sundadanio axelrodi care should be provided to the fish as they are very peaceful but needs a lot of attention. These fishes are found as pets all over the world.

Did you know...

Neon blue rasbora (Sundadanio axelrodi 'blue') do not hibernate.

They can cohabit with other small fish species but do not form schools with them.

Is the Sundadanio axelrodi endemic?

The population of the neon blue rasbora (Sundadanio axelrodi 'blue') is declining due to frequent habitat degradation and the small distribution of the fish. Axelrod's rasbora is only found in a limited number of places in the world (around 10).

In nature, these fish species are endemic to Southeast Asia in the Bangka Islands, Greater Sunda Islands, and Riau Archipelago Islands of Sumatra and Borneo. They are also endemic to West Kalimantan, South Kalimantan, and Central Kalimantan provinces in Indonesia.

Can Sundadanio axelrodis be kept in aquariums?

The rasboras are a very hardy and peaceful fish species and are loved all over the world as a pet. Due to their habitat origin of blackwater pools and streams, it is necessary to keep the water in the aquarium tank similar to that of their natural home.

Leaf litter should be provided in the water to make it seem like their actual habitats. The pH of the water should be no more than five in the planted aquarium tank.

The temperature of the water should be kept between 163-174 F (73-79 C) in the tank, and the water quality should seem like the same to replicate their natural homes. The fish needs excellent water quality to thrive and is not recommended as a pet for beginners.

There should be moderate lighting, and the tank should be dimly lit. The diet should be flake food, freeze-dried Tubifex, and Bloodworms.

Cyclops, Daphnia, and chopped bloodworms can also be fed as food to the fish species. The aquarium tanks should be sized around 10-12 gallons.

These blue fish are one of the best alternatives to the neon tetra or the cardinal tetra.

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 horn shark facts or thresher shark facts pages.

You can even occupy yourself at home by coloring one of our free printable sundadanio axelrodi coloring pages.

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 >
Fact-checked by Sonali Rawat

Bachelor of Arts specializing in English Literature, Masters of Art specializing in English and Communication Skills

Sonali Rawat picture

Sonali RawatBachelor of Arts specializing in English Literature, Masters of Art specializing in English and Communication Skills

Sonali has a Bachelor's degree in English literature from Guru Gobind Singh Indraprastha University and is currently pursuing a Master's in English and Communication from Christ University. With considerable experience in writing about lifestyle topics, including travel and health, she has a passion for Japanese culture, especially fashion, and anime, and has written on the subject before. Sonali has event managed a creative-writing festival and coordinated a student magazine at her university. Her favorite authors are Toni Morrison and Anita Desai.

Read full bio >