Celestial Pearl Danio Care Guide (aka Galaxy Rasbora)

Celestial Pearl Danios (aka Galaxy Rasboras) are a beautiful freshwater species that we recommend all the time.

Their mix of beauty and straightforward care requirements make them a no-brainer for any aquarist looking to bring a splash of color to their tank. Even though they’re a popular nano aquarium choice, they’re more versatile than many people realize.

This guide will teach you everything you need to know about Celestial Pearl Danio care. Diet, tank mates, breeding, and more!

Species Summary

The Celestial Pearl Danio is a recently discovered freshwater fish first shown to the world in 2006. They were originally found occupying small ponds in Myanmar. Back then, they were given the scientific name Celestichthys margaritatus.

Due to their unique looks, these fish were highly sought-after in the aquarium industry. This quickly led to a rapid decline in the wild population and put the whole species in danger. Luckily, in 2008, breeders were able to start breeding the fish in captivity. As a result, the wild population has since stabilized.

Around the same time, scientists discovered that the fish was actually part of the Danio family (and not technically a rasbora species). Thus, they were given the new scientific name of Danio margaritatus.

No Spam, Subscribe for Cool Fish Stuff!

* indicates required

Celestial Pearl Danios, also known as Galaxy Rasboras, are now an extremely popular aquarium fish that can add tons of natural color to your tank. Like any other fish species, proper care is a must if you want to help these beauties reach their full potential.

Author Note: Despite the wild population of Celestial Pearl Danios being under control, we owe it to these fish to be extra diligent. This means buying from reputable sellers or breeders and only purchasing fish you’re 100% sure you can take care of.


In the right conditions, the average Celestial Pearl Danio lifespan is between 3 and 5 years in captivity. There are a few things that can impact their lifespan. The biggest are poor water conditions and stress.

These fish are quite small (they’re great nano fish) and very peaceful. Minor changes in water quality can have a big effect on them. Plus, their peaceful nature puts them at risk for attack when paired with aggressive fish that look for a fight.

Author Note: As long as you follow the care recommendations in this guide you should be just fine. These fish aren’t nearly as complicated as aquarists make them seem! Simply follow our instructions and they should live a long and happy life.


The thing that first captivated the aquarium community when Celestial Pearl Danios were discovered was their looks. These fish are absolute stunners! They’re colorful, yet offer up a dream-like aesthetic.

The Celestial Pearl Danio

The base coloration of these fish is deep blue. However, their bodies are covered in pearl-like spots. This creates the galaxy-like pattern that led to their name.

That’s not all.

The fins take on a deep orange or red color. The vibrant hue creates a beautiful contrast to the rest of their bodies. The same color can be found of the fish’s belly as well.

Compared to the size and shape of their bodies, their fins are actually quite prominent. A tall dorsal fin juts out of the lower third of the fish’s body like a colorful sail. You can also see two pelvic fins and a wide anal fin.

All of the fins have two black lines running through them. There are some transparent areas as well, giving the fins a very unique look.

Celestial Pearl Danios have sexual dimorphism. This means that there are physical differences between males and females. The distinctions are subtle, but understanding them can prove to be very useful. We’ll get into why in a bit.

Generally, males are more slender than females. Their bodies have a thinner profile compared to the plump shape of the females. Not only that, but the male coloration is more vibrant.

Females tend to have slightly duller hues of orange rather than the eye-catching shades of red that the males have.


The average Celestial Pearl Danio size is about one inch in length when fully grown. Most fish will get close to this size at about 3 months of age, which is when they reach sexual maturity.

We always found it impressive that there are so many visual details crammed into one tiny body. It makes viewing their beauty even more interesting because you really have to focus when looking at all the colors and patterns! When they swim around you end up with a very textured effect that’s hard to put into words.

Author Note: The great thing about their small size is it makes the Galaxy Rasbora an excellent addition to nano tanks. If you’re someone who’s set on keeping a small and tidy aquarium, this fish might be for you!

Celestial Pearl Danio Care

Celestial Pearl Danio care isn’t difficult. They’re relatively hardy and can be cared for by anyone with some modest aquarium experience.

Two galaxy rasboras swimming in their tank

With that said, it’s important to provide these fish with the right conditions. They’re prone to stress and can show signs of deteriorating health if things aren’t done just right.

Making sure their habitat has everything they need is the first step in ensuring a long and happy life for these fish. Sometimes owners get lazy with the simple stuff, and it sabotages their care efforts later on.

Start things off right. It’s better for you and your fish.

Tank Size

Because they only reach about an inch in length, the minimum tank size for Celestial Pearl Danios is 10 gallons. This is assuming you’re keeping roughly 5 or 6 of these fish together (more on that in the tank mates section).

To keep things easy, the rule that many aquarists use with this species is roughly 2 gallons per fish. This allows them enough room to swim comfortably and find places to hide without being packed in next to each other.

Author Note: Just because these fish can be kept in smaller tanks, it doesn’t mean they won’t appreciate more room. If you have space and don’t mind springing for a slightly larger aquarium, it will definitely improve their quality of life.

Water Parameters

The best method for caring for Celestrial Pearl Danios is to mimic their natural environment. In the wild, these fish are found in shallow ponds that are rich with vegetation. As a result, the water is quite clear and pure.

The presence of this vegetation also means these ponds are low in salt and minerals. Try to remember this and stick to those conditions as much as you can. This will help them stay healthy and minimize stress on their system.

Here are some recommended water parameters for Celestial Pearl Danios:

  • Water Temperature: 73°F to 79°F
  • pH Levels: 6.5 to 7.5
  • Water Hardness: 2 – 10 dKH

Investing in a good water test kit is something we highly recommend. Getting accurate readings it the first step in being able to monitor your aquarium and make adjustments.

What To Put In Their Tank

When you’re setting up your tank, including vegetation is a must! As we mentioned earlier, Celestial Pearls were first found in small ponds filled with plant life. The plants help to keep the water in good condition while also giving the fish plenty of things to snack on or hide in.

A celestial pearl danio swimming through a well-planted aquarium

Because of their love for plants, Celestial Pearl Danios have become a favorite among those who like aquascaping. This unique art form involves creating surreal environments using a wide variety of plants.

Celestial Pearls love these kinds of environments. The plants offer places to hide, ensuring that your fish stay comfortable. Plus, the leaves of large plants are often used for breeding.

You can be flexible when it comes to this, so any of the popular plants will probably work out just fine.

Rocks and driftwood are good as well. As long as the fish have some natural hiding spots, they should be comfortable and stress-free.

When it comes to the substrate, you have a bit of variety. Galaxy Rasboras tend to stay towards the bottom half of the aquarium. However, they’re not known to dig.

It’s recommended that you choose a substrate that works with whatever plants you decide to include. Dark fine sand is a good choice due to its versatility. It’s good for plants and is easy to clean.

Proper filtration is key to keeping Celestial Pearls healthy. These fish don’t tolerate pollutants very well, so strong filtration is a must.

You can utilize a standard “hang on back” or canister filter (such as the Fluval FX4). Just make sure to fill any inlet tubes with sponges. Remember, these fish are small!

Strong pumps or air bladders are not necessary. Celestial Pearl Danios prefer a low water flow rate like the ponds of the natural environment.

Common Possible Diseases

There are still many things being discovered about Celestial Pearl Danios. Luckily, scientists and aquarists haven’t found any new diseases that are exclusive to these fish. However, they are susceptible to other common diseases.

Fin rot, in particular, is known to affect Celestial Pearl Danios. You can identify this condition by taking a look at the edges of their fins. The tissue will start to become discolored and frail. Eventually, parts of the fin may even start to fall off.

This disease is caused by a couple of things. First, it can be a direct result of poor water conditions. You can avoid this by continually monitoring the pH levels and temperature with a reliable water testing kit.

Fighting is also known to cause fin rot. When the fins become damaged, they’re at a higher risk of getting the disease.

Fortunately, treating fin rot is easy with the right tools. The first step would be to bring water conditions back to optimal quality. Then, you could use antibacterial medications that are made specifically for this condition. With the right care, the fins will grow back and look as good as new!

Author Note: If you’re diligent about maintaining the water quality in the aquarium it will greatly reduce the chance of disease and illness. Take this seriously, and you won’t have to deal with problems later.

Food & Diet

Celestial Pearl Danios are omnivores. They aren’t picky eaters in the wild. As such, their diets can vary significantly.

Usually, these fish will feed off algae and plants. Plankton is also a favorite snack that they consume in the wild. They may also eat small vertebrae as a source of protein.

In captivity, the fish will do just fine on commercially available flakes or pellets. Just make sure that it’s high-quality and provides a balanced diet. You may also want to think about getting pellets that sink.

Galaxy Rasboras spend most of their time at the bottom half of the fish tank, so you need to ensure that the food is getting to them.

Also, keep an eye on these fish when you feed them to learn their habits. You don’t want to overfeed them or pollute their tank with food they don’t consume (this is a quick way to ruin the water quality).

One of the trickier parts of finding the right food is choosing something that they can physically eat. The fish have very small mouths, so you’ll need to invest in small pellets they can safely eat.

In addition to pellets or dry flakes, you can supplement their diets with live food or protein-rich snacks. Brine shrimp, krill, Grindal worms, and live Daphnia are all good choices.

Behavior & Temperament

For the most part, Celestial Pearl Danios are peaceful fish. They tend to group up and spend their time exploring the tank. Contrary to popular belief, Celestial Pearls are not true shoaling fish.

While they appreciate spending time with each other, they also like to branch off and do their own thing. They tend to live separately once they get accustomed to their environment.

The only thing you need to worry about in terms of temperament is the potential for fighting. Remember how we said that it’s important to identify males and females? That’s because you need to make sure that there aren’t too many males in the tank.

Males will fight over females constantly. This can lead to serious injury or even death. While males tend to be more vibrant than females, we recommend keeping more females in the tank. This can reduce the competition and keep fighting to a minimum.

Tank Mates

Celestial Pearl Danios do best with fish of the same species. We recommend keeping 6 to 7 fish in the same tank. Like we said earlier, try to get more females than males.

As for other fish species, they do well with similarly sized peaceful fish. Guppies, Neon Tetras, and other non-aggressive fish do very well with Celestial Pearl Danios. You can find fish that occupy the higher parts of the tank so that your Galaxy Rasboras have their own space.

A celestial pearl danio with a tank mate

The main thing you need to avoid is getting tank mates that are significantly larger. Big fish can view Celestial Pearls as food.

Even large peaceful fish can pose a problem, so stick to species of the same size. This can avoid unwanted aggression and competition over food.

Here are some great Celestial Pearl Danio tank makes to consider:

Author Note: When considering tank mates of another species it’s important to see how much space they need. There might be situations where you’ll need to increase the size of your tank to make everyone happy.

Celestial Pearl Danio Breeding

Breeding is a straightforward process. There is no specific season that the fish breed. Many aquarists recommend feeding your fish a good supply of live food to trigger the breeding process.

Celestial Pearl Danios are egg layers. Females will typically search for spots in the aquarium that have low water flow. Most often, this is around plants.

She can lay upwards of 30 eggs at once time. They are incredibly tiny. However, it’s very important that you keep an eye out so you know where they are.

This is because males will eat the eggs as soon as they find them! Once all of the eggs are laid, you should gently remove them from the main tank and place them in a spawning tank.

Once they’re safely in the spawning tank, the eggs will incubate for 2 to 4 days. Then, the tiny fry will hatch. You can feed them micro foods to keep them healthy.

If you have an established tank with plenty of vegetation, the fry will use the plants for food. As they get older, you can move onto baby brine shrimp, small worms, and flakes. The fish should reach maturity by about 3 months of age.            

The Wrap Up

As you can see, there’s a lot to like when it comes to the Celestial Pearl Danio. These fish bring a unique type of beauty to any freshwater tank, and we’ve been fans of them for years.

If you’re considering getting a Galaxy Rasbora we highly recommend it. They’re a ton of fun to observe and can be taken care of by owners with a variety of experience levels.

As long as you stick to the care recommendations in this guide, keeping these fish is a piece of cake.

Have fun!

You May Also Like