Galaxy Rasbora Care, Tank Mates, Size, Breeding Complete Guide

If you are a true aquarist, you have probably heard of the Galaxy Rasbora, a small Asian fish that has won the hearts of thousands of fans.

Since its introduction in 2006, this fish has not stopped gaining followers around the world . What is behind its popularity? How to take care of them correctly? In this post we will solve all your doubts!


The galaxy rasbora, scientifically known as Danio Margaritatus, is a small fish with a bluish body and white or yellow spots, colors reminiscent of a distant galaxy. Hence its common name.

The truth is that it is a relatively new fish in the world of aquariums. Since its discovery in 2006, the Galaxy Rasbora has continued to gain popularity, becoming a sensation in the United States and Europe.

Is in danger of extinction?

As we mentioned before, the popularity was such that it gained in mid-2007 that this species was in danger of extinction. Apparently, many people had not taken the time to try to reproduce this species, so they preyed on them in their natural habitat.

Fortunately, it was discovered that reproducing them is very simple, since they belong to the danios family, a very simple family to raise. To this day, the majority of fish sold in stores have been bred in captivity.

Morphology How do they look?

The truth is that part of the great popularity of these fish is due to the way they look. Despite being such a small fish, they have characteristics that make them one of a kind.

Glaxy Rasbora Chart
🐟 The size of this fish is only 1.5 centimeters in adulthood.
🐟 The shape is like any other rasbora, flattened on the sides and slightly plump.
🐟 Its head is flat on the sides and its mouth is quite small.
🐟 The dorsal and anal fins are slightly back, they are transparent and are crossed by black and orange stripes. Also, they are pointed.
🐟 The color is one of its most beautiful parts, since they have a blue background, dotted with yellow or silver spots.
🐟 In addition, its abdomen is a deep orange color. Coloring will vary based on gender, mood, and water quality.

Sexual Dimorphism

In general, differentiating between males and females is quite easy , since it will be enough to take a look at their colors and size.

Female Male
The females are larger and have a  more swollen abdomen .
The coloration of the females is more grayish and their abdomen is colorless.
The body is more yellowish and grayish.Their fins 

may be orange but they only have  one or no stripes.

Males are thinner and smaller.
Its coloration is more intense , and its abdomen is more orange.
The body is more bluish and intense. The fins of the males are deep 
orange with two black  stripes .

Where do these fish live?

The habitat of these fish dates back to Myanmar (formerly Burma), more precisely in Inle Lake. This lake is 884 meters above sea level and is generally used for watering livestock.

This lake has unique conditions of its kind, such as a warm temperature, a depth of no more than 3 meters and acidic water, not very hard and with a relatively moderate amount of tannin.

Galaxy Rasbora care

Now that you know the Galaxy Rasbora, it is time for you to know how to keep this species in our aquariums.

So if you want to get the best possible results and enjoy this species 100%, follow our following tips.

The aquarium and its parameters

The aquarium will be the new home for our rasboras, so we have to provide them with a place that is as close to their natural habitat as possible. Otherwise, our microrasboras may feel uncomfortable.

According to expert breeders, the best conditions to keep a group of galaxy rasboras are the following.

The aquarium

  • The size of the aquarium should be greater than 20 liters, although the ideal is from 50 liters.
  • We will add a school of at least 10 specimens .
  • It is recommended that they have a good amount of plants.
  • The temperature will go between 22 – 28 ° C (ideal 25 ° C)
  • The PH will be around 6 – 7.5 (Ideal 6.8).
  • The GH will go between 3 to 6 degrees.
  • His KH will oscillate between 2º-3º.

Powering the Galaxy Rasbora

In its natural habitat, this fish feeds on small invertebrates as well as small algae and plants. That is why it is considered an omnivorous fish. In the aquarium you can eat a variety of foods.

Galaxy Rasbora Feeding

The basis of their diet will be dry food , such as small granules or scales for omnivorous fish. The vegetable contribution will be provided by spirulina powder or flakes, and we will dose it once a week. Live food such as daphnia , grindal worm or newly hatched brine shrimp will be perfect snacks, which we will feed them once a week.

Their compatibility and their behavior

The galaxy microrasboras are somewhat scary, peaceful and quite active fish, so their companions will have to be preferably small and peaceful animals .

Otherwise they may end up being the food of one of your tankmates.

Compatible and unsupported fish

Next I will name you some fish that galaxy rasboras can live with, as well as other fish with which they can definitely NOT live with.

The reproduction of the Danio Margaritatus

As we mentioned earlier, this fish belongs to the danios family , a family of fish that has been bred for decades, so reproducing the galaxy rasboras is quite simple.

The reproduction of these fish is linked to the moss, where they will spawn and lay their eggs. Without further ado, let’s see how to breed these fish step by step.

The reproduction

  1. It is advisable to keep 3 females for each male , in order to increase the number of offspring.
  2. The mating will take place by itself, so we must provide moss in abundance.
  3. At some point, the fish will lay fertilized eggs on the moss.
  4. After spawning, we must separate the eggs and the moss in a farrowing or breeding aquarium.
  5. After 3-4 days , the eggs will hatch.
  6. 4 days later , the fry will consume their yolk sac and will need to be fed.
  7. We should feed them with artemia nauplii during the first week, between 3 or 4 times a day.
  8. Then, we will supply very ground food , or cooked egg yolk.
  9. We will increase the size of the food as they grow.

Do not forget that if you have a good Microscope  (check specialized page) you will be able to observe the small fry much better.

The price of Galaxy Rasbora

The price of Galaxy Rasbor is usually somewhat high , so a single copy can reach 3 euros, or a little more. However, never forget that you can contact an individual breeder , buy with friends in large quantities and get better and better, or, if you are a little more daring, import your own fish.

Final tips for maintaining a Galaxy Rasbora

Finally, I would like to give you a couple of extra tips, which I have been collecting over the years, so that you can keep these incredible fish in your aquarium. Let’s see what they are!

Do not forget that it is a fish, and no matter how small it is, it will need at least 20 liters. They are ideal fish if you have an aquascaping project or a shrimp, since they are peaceful, small and very calm Choosing this fish is a great decision, since it will give a lot of showiness to each and every one of your projects.