The Ultimate Guide to the Celestial Pearl Danio (Galaxy Rasbora)

The Celestial Pearl Danio is a freshwater fish found in small, vegetated ponds in South East Asia.

These fish boast plenty of color from the white pearl like spots on their sides to the red coloration on the fins.

Discovered within the past decade, aquarium hobbyist have quickly adopted and fell in love with these little Danios.

They are well suited for tanks that are packed with vegetation and other colorful fish that mimic their peaceful nature. It is true that these fish are timid, they work perfectly in communities full of Guppies, Mollies and Tetras.

In this guide we’re going to take a look at how to care for them, their ideal diet, breeding, tank requirements and much more.

Category Rating
Care Level: Medium
Temperament: Peaceful
Color Form: White Spots Along the Body with Red Coloration on the Fins
Lifespan: 3-5 Years
Size: Up to 1 inch
Diet: Omnivorous
Family: Cyprinidae
Minimum Tank Size: 10 gallons
Tank Set-Up: Freshwater: Highly Vegetated and Shallow
Compatibility: Peaceful Communities


Celestial Pearl Danio

The Celestial Pearl Danio, also commonly called the Galaxy Rasbora, shook up the aquarium world when they were discovered in 2006. The vibrant colors and peaceful nature make this fish extremely popular.

Scientifically known as Danio margaritatus, this fish is a member of the Cyprinidae family. It is a plant reliant fish that adds a pop of color and lively activity to any tank.

Typically, the Celestial Pearl Danio lifespan is 3-5 years in stable aquariums.

Despite their small size of Celestial Pearl Danios, they can help to liven up any planted aquarium. They get along with a wide range of other fish even though they are somewhat timid.

They will be constantly on the move and exploring the lower portions of the tank.

Due to their small size and shy nature, it is best for them to be kept in a community of fish that mirror their behavior and size. If not, they can easily be preyed upon or out competed by larger fish.

Beginners who are looking to keep a school of Galaxy Rasboras must keep in mind their behavior and habitat over all else.


Celestial Pearl Danio Appearance

A group of these fish can add both color and energy to any plant backdrop they are given. The white spotted bodies combined with their red or orange fins allow for the fish to stand out among its habitat.

These fish are small fish, typically being at most 1 inch from head to tail.

The most distinctive part on these fish is the coloration of the fins. All fins have two parallel black lines with bright red or orange coloration depending on the sex.

When looking at a group of these Danios, you will likely notice the difference in coloration between individuals. This is because they have sexual dimorphism; the males and females look different.

The males are thin and often more vibrant in color, especially on the tail, whereas females are slightly duller and more round in shape.

Courting males will even gain additional deep red coloration on their stomachs. This coloration can lead people to only seek out males for their tank; unfortunately, keeping a ratio of males to females is important to keep a healthy group.

Males will constantly fight each other for mates so having more females to males will lower the risk of fighting.

Because they are such a new species, conversations about where it fits into the Cyprinidae genus go on to this day. They share their general shape with other members of its family and even have the spotted pattern of other danio fish such as the dwarf danio fish (Danio nigrofasciatus).

Celestial Pearl Danio Habitat and Tank Requirements

Celestial Pearl Danio in Aquarium

The Celestial Pearl Danio is a freshwater fish found in small, highly vegetated shallow ponds in South East Asia (Myanmar).

These ponds have relatively low water movement with high levels of light. The light breeds plenty of vegetation and algae for them to both hide and feed off.

In the wild this fish survives best when surrounded by high levels of live vegetation and other areas to hide (rock or driftwood).

It is also important to note that there still is a lot to be discovered about their habitat and species in general. Being discovered in 2006 means that new discoveries are likely.

Tank Conditions

In order to replicate their natural environment inside your tank, you’ll need to include plenty of plants, buried in a dark substrate.

Because their natural home is mostly small ponds they are accustom to a wide variety of aquatic plants. These plants not only help keep the tank clean, they also allow for the fish to hide and even lay eggs.

These hiding places will become increasingly important as you increase the number of males in your tank. Males compete for mates constantly so without places to hide, losing males are subject to extreme harassment often leading to injury and sometimes death.

You should also include plenty of rocks and driftwood to mimic their natural environment.
The ideal temperature for these fish is around 73-79°F. The preferred pH is between 6.5 and 7.5. Keeping the hardness at a soft to medium level is necessary.

These levels are a little wide due to how hardy these fish are. What is important though, is ensuring that these fish are kept in water with stable conditions.

They don’t need a water flow as they are used to slow moving, or still waters. Lighting wise, keep this moderate, to high.

Size of Aquarium Needed

When keeping Celestial Pearl Danio in a tank, nothing under 10 gallons should be used. Keeping 5 or 6 individuals, mostly females if possible, is the best way to go given their grouping nature.

If you want to increase the number of them that you keep, then a larger tank will be needed. Aim for around 2 gallons per fish.

Also try to keep the tank relatively shallow. This will mimic the shallow nature of their native home and will make the fish feel more comfortable.

Tank Mates and Compatibility

Celestial Pearl Danio Tank Mates Because of the shy nature of these fish it is important to keep them around other species of the same size and nature. This will allow for the Celestial Pearl Danio to not be eaten by larger fish or be out competed by faster, more aggressive fish.

They may be shy but that does not mean they are not peaceful and work well in small communities: Tetras, Guppies, Corydoras, and Killifish are perfect tank mates for them. All of these fish are relatively peaceful and will complement the shy nature of the Galaxy Rasbora.

A great example of a complementing fish is Neon Tetras. They tend to stay towards the surface and bring a good vibrant color to the community. With Tetras on top all areas of the water column will be full of fish.

Fish from the same species or area are also great tank mates as most of them share the same general behavior.

Be aware that these fish are known for attacking and eating juvenile shrimp. If you have larger, adult shrimp however you should not worry. Once shrimp become adults they are normally left alone.

If you are putting multiple species of schooling fish together then it requires more gallons of water per fish. Keep this in mind if you have a smaller tank.

Celestial Pearls work well with dozens of types of fish so long as they are peaceful in nature. This is why these fish make amazing additions to calm community tanks.

Aggressive fish such as Cichlids, Oscars, or Jack Dempsey’s will prey upon fish that are slower and smaller than them; so you should avoid these fish.

Keeping Celestial Pearl Danios Together

Celestial Pearl Danio live in groups, so you should try to keep a group of 5 or 6; this will help keep them all healthy and active.

As said before however, do keep an eye on how many males you have if your tank is small. In a small tank with few hiding places, males who are less dominant will be subject to attacks from other males.

To keep all individuals safe, ensure that you have plenty of room for fish to live and keep a healthy ratio of males to females. Including many plants will give them a natural feel and also gives the males a good hiding place for when they are competing for females.

Diet and Feeding

In their natural habitat, these fish eat many species of algae, plants and zooplankton. They have also been known to eat small invertebrates and worms. These fish are mostly opportunistic feeders which is why their diet is so varied.

In an aquarium however, these fish will eat dry food such as flakes and pellets as long as it is small enough to fit into their mouth.

Feeding can be problematic if they are too scared to eat. These fish will most likely stay toward the bottom half of the tank so use sinking pellets.

Another option for feeding is using small live or frozen food such as brine shrimp or krill. The krill especially will help with the red coloration of the fins. White worms are a good low-cost alternative.

Live Daphnia, Grindal Worms, Moina all make good food for these small fish and help to enrich their diet.

Always remember to cycle the food that they eat. Try not to only feed them one type of food (i.e. only pellets). This will keep them healthy and even more vibrant so long as they are eating the right type of food.

General Tip

For any tank and any fish, watch the tank as you feed them and learn each fish’s behavior when feeding. You will learn a lot about individuals which can lead you to feeding them more effectively.

Some individuals are going to be shy and some will be braver no matter the species. Knowing your individual fish is important so you can cater to their needs accordingly.

This limits waste in the tank and in the long run will mean less cleaning and time spent for you.

It is important to keep an eye on the fish you have in your tank to make sure they are not getting out competed for food.

If this happens consider changing the way you are feeding your fish. Instead of all at once, feed the faster fish on one side then use the other side to let food sink down to where they are hiding.

Celestial Pearl Danio Care Guide

Celestial Pearl Danios

As with most fish, keeping a close eye on these fish from the start is important.
One thing to watch for is the courting of females by the males.

Much of the time spent by males is courting females. This leads to males fighting over potential mates.

An easy way to see if a fish is fighting is torn fins and other signs of bite marks on their sides. Not only is the fighting of males directly bad for the loser, but damaging of fins can lead to Fin Rot.

Fin Rot is extremely common in aquarium fish and can be caused by poor water quality and, yes, previously damaged fins. But luckily there are plenty of ways to cure and prevent this from happening.

If you see a fish that has this disease be sure to increase the amount of water changes you are performing. The use of antibacterial medications such as Oxytetracycline, Tetracycline, and Chloramphenicol will help increase the chance of infected fish surviving.

Always make sure to monitor the pH and water temperature of the tank. If these are not in the ideal range it can cause stress to the fish, leading to Fin Rot.

Something else to keep in mind is the misconception that they are truly a schooling species of fish. May aquarists see these fish group together and confuse this with schooling.

While it is true that they will group together a good portion of the time, Celestial Pearl Danio groups will separate, especially after being acquainted with their new home.

If you look at a true schooling species like a Neon Tetra, you can see the difference in schooling behavior.

Breeding Celestial Pearl Danios

Breeding is fairly straightforward. Look for female fish that are darker in color and have a rounder abdomen. This means that she is ready for spawning.

The use of live food has been noted to stimulate spawning in some cases due to their natural habitat.

Celestial Pearl Danios are egg layers. Typically, she’ll lay the eggs somewhere with less water movement but they can appear anywhere.

Females can lay up to 30 eggs at a time; however, it is more likely to get groups of around 12. Eggs will incubate for 2-4 days, after which they will enter their larval stage and begin to swim. If you spot the eggs early it is imperative that you remove them and add them to a breeding tank. Males will seek out eggs and eat them constantly.

The breeding tank should be set up similarly to the main tank with vegetation and low to medium water movement.

Start out by feeding them with micro foods for the first week. After that you can move on to baby brine shrimp until they grow to be adults.

The growth is rapid as the fry take on adult coloration and size within the first year.

Is the Celestial Pearl Danio Right for your Aquarium (Summary)

Celestial Pearl Danios are hardy fish that make great additions to calm communities. Their bright colors and grouping nature have helped to liven up tanks ever since they were discovered 12 years ago.

Are these fish right for your aquarium?

If you have a highly vegetated tank above 10 gallons and are ready to watch how all your fish eat and live together: yes. These fish add good color and complement communities really well.

If your tank is small or you lack vegetation, consider other species such as Guppies Or Tetras which are easier to keep.

Starting with these fish will allow you to build the knowledge base needed for you to step up to the level of more complicated fish.

Have you ever kept Celestial Pearl Danios, or are you thinking about keeping them? Leave a comment in the comments section below.

Robert Woods Portrait
Robert Woods is the creator of FishKeeping World, a third generation fish keeper and a graduate in animal welfare and behavior. He is also a proud member of the Association of Zoos and Aquariums, the Marine Aquarium Societies of North America and the Nature Conservancy.


  1. I bought the last 4 babies from a lfs and they quarantined well before adding in with some neon tetras. We’ve enjoyed them and I’m looking for to add more. Would like to find a site that has photos of the growth so I can better understand how old they were when purchased.

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