Celestial Pearl Danio: Care, Diet, Lifespan, Tank size and Much More

Celestial Pearl Danio care guide

The Celestial Pearl Danio is one of the most flashy species of nano fish in the aquarium space right now. 

Beauty isn’t the only advantage this freshwater fish bundle, they are substantially hardy and can survive varying water conditions. 

All in all, they are fairly easy to care for and even beginners can keep them successfully, provided they follow the recommended guidelines on tackling their rather strange social behavior.

I say strange because differ in that regard with popular nano species like Tetras, Danios, Livebearers, Rasboras, White Cloud Mountain Minnows and so on.

In this guide you will find out how they differ with above species in terms of the social behavior.

The guide also provides you with everything you need to know to successfully keep the Celestial Pearl Danio from tank size, water parameters, tank mates, food and diet, breeding and much more.

The Celestial Pearl Danio, also known as the Galaxy Rasbora, is a freshwater fish that is quite popular in the aquarium space. What’s surprising is that it was discovered just recently.

Initially, they were regarded as part of the genus microrasbora but two years later, a study was conducted and it was gathered that they aren’t part of the microrasbora instead belong to the danio genus. 

Owing to their unique fascinating looks, they were highly sought after in the aquarium trade immediately. 

Not long after that, news of their population decline start to circulate around, and many people blamed fish hobbyists. 

However, a through research was conducted and it was gathered that the percentage of the fish taken for the hobby wasn’t at all significant compared to their overall population (we are all the luckier for that).


Understanding the habitat of any fish species helps greatly in providing the ideal tank conditions for it by mimicking the habitat conditions in the tank. There are few important details to grab about the Celestial Pearl Danios habitat. 

The Celestial Pearl Danio was discovered in 2006 in a small plant laden spring-fed pool in the Southeast Asian nation of Burma. The area contains several pools and the fish can be found in many of them. 

The pools are located in the mountainous region of the Hopong town in the outskirts of the shan capital of Taunggyi. Grassland and Rice paddies are mostly what makes up the area, plus a fascinating collection of different aquatic plants.

This area is home to many species discovered in recent years but none of them is as fascinating as the Galaxy Rasbora which is why it surpassed them in popularity. 

As of writing this post, this is the only known habitat of this species. That is not to say it doesn’t exist elsewhere in the wild.

It is just that its a considerably new species, and possibly so many things are yet to be known about it. 

Celestial Pearl Danio Care Snippet

  • Maximum fish size: 1.0 inch
  • Minimum tank size: 10 gallons
  • Aquarist Experience Level: Intermediate – Expert
  • Temperament: Peaceful
  • Temperature: 73°F to 79°F
  • PH: 6.8 to 8.4
  • Hardness: 5-10dGH
  • Diet: Omnivore
  • Care Level: Relatively easy
  • Ideal tank mates: Neon Tetra, Ember TetraChili Rasbora, Guppies, Cory Catfish, Sparkling Gourami, Honey Gourami, Mollies, et Cetra


At the time the Celestial Pearl Danio was discovered and its picture started circulating on the internet, lots of hobbyists didn’t believe it was real because of how marvellous they looked

Many hobbyists thought how could something this beautiful have been missed in the aquarium trade these whole years. 

Galaxy Rasbora is distinctively looking and differ completely from any of the popular colorful freshwater fish species like Tetras, Guppies, Bettas and so on. 

They have deep blue hue as the background color followed by white spots creating a galaxy like a pattern which is where the name originated. 

They have an outstandingly looking fins covered either in orange or red hue complementing the rest of the body. Their belly is covered in the same color as the fins.  

A tall dorsal fin protrudes at the lower third of the fish’s body making them look like a multicolored sail. They have two pelvic fins and a broad anal fin. 

All fins except the pectoral contain two parallel black lines running through them. This pattern exists on each lobe of the tail fin. The rest on the areas uncovered by this pattern on the fins are transparent. 

The Celestial Pearl Danio have what’s called sexual dimorphism and it basically means differences in male and female physical appearances. 

Celestial Pearl Danio appearance
  • Males have slender body while females have a rounder body
  • Males have a more strikingly colored body, especially on the tail.
  • Females usually have a bit pale orange hues as opposed to the striking red hues the males’ posses.
  • During courtship, the color on the males’ abdomen becomes even more vibrant than usual. 

These differences are important to understand for the sake of breeding.


Like popular species such as the Chili Rasbora, Ember Tetra, Dwarf Rasbora, and Rosy Loach to mention a few, Celestial pearl Danio is also among the smallest freshwater fish. 

The Celestial Pearl Danio has an average maximum size of about 1 inch when fully grown. Under right tank condition and with proper care they can max out their size within 5 months.

In my opinion, this fish tiny size has only contributed to its mesmerizing beauty. I can’t imagine it looking better if it were any bigger. It’s surprising looking at all those patterns and colors on such a tiny body like its computer-generated.

Celestial Pearl Danio Lifespan

The Celestial Pearl Danio lifespan ranges between 3 to 5 years. Ideal water conditions that closely resemble their habitats’ is the key to prolonging their lifespan, together with proper feeding and ideal tank mates inclusion.

Temperament and general behavior

Celestial Pearl Danio mostly spends their time in groups exploring the tank but not in a schooling fashion

For the most part, schooling fish hang out peacefully among themselves and do not break from the group once they become matured.

Celestial Pearl Danio, on the other hand, are known to fight among themselves and tend to split from the group and do their own thing once they start becoming matured and familiar with the new environment.

The males have a habit of engaging in what can be described as a custom dance. This can be detrimental to smaller fish among them who can not swim away fast. 

A dominant male usually emerges from the group and in most times can be quiet ferocious. It uses its teeth to inflict damage on the rest of the fish (I know its really surprising considering their tiny size).

The key to curtailing these fights is getting the male to female ratio right, and ensuring you use a decently sized aquarium equipped with abundant plants for an easy getaway. 

Male Galaxy Rasbora fight constantly over females. In some cases, the dominant male will kill all the other males to make sure he is the only one remaining.

For this reason, its recommended you have at least 2 females for every male, 3 females per male would be better. 

I understand many people might not be willing to do this considering the males generally, are nicer looking. Implementing this recommendation however will make you have a more peaceful tank. 

Tank size and Requirements

Even though Galaxy Rasbora only grows to an inch they are not suited for anything less than a 10 tank.

These little beauties might make a hobbyist with access to just a small 5-gallon tank consider them but the thing is, they will not reach their full potential in a tank that size. 

Nano fish like this, produce so little waste. For that reason, you can apply the rule of thumb of allocating 2 gallons of space per inch of a fish.

So in a 10-gallon tank, you can conveniently have up to 5 Celestial Pearl Danio and still have space for proper tank decoration. I recommend you keep no more than 2 males out of that 5. 

Consider upgrading to a bigger tank like a 20-gallon tank if at all possible. Just like with any other aquarium fish, they could use more room to realise their full potential.

It’s worth pointing out that they will adapt easier if you provide them with a relatively shallow tank. In their habitat, they are used to shallow waters.

Then there is the matter of fitting the tank with all the fish requires to adapt easier and live at their best. These requirements entail aquascaping, tank decoration, filtration and substrate.

Celestial Pearl Danio swimming in a heavily planted tank

Aquascaping for Celestial Pearl Danio

If you are someone who loves heavily planted aquarium tanks, then you are gonna love these fish. Like we discussed before, Celestial Pearl Danios environment is characterized by the presence of different aquatic plants. 

Consequently, they will not thrive in a skimpy planted tanks. Aquarium plants serve the purpose of more than just mimicking their habitat. They also helps provide areas and spots they can hide in and lay their eggs during breeding times.

Giving their propensity for fighting, its easy to imagine the kind of consequences you can have if their tank isn’t adequately planted.

The plants also help increase water quality, plus they have a habit of snacking on them occasionally. 

When it comes to selecting the plants I highly recommend easy-care aquarium plants such as Java Fern, Anacharis, Java Moss or Vallisneria. Any of these plants can be planted at the substrate.

Floating plants won’t be necessary because the fish are used to open sunlight in their ponds. However, if you still want to make use them, make sure you have enough open space where light can penetrate.


Celestial Pearl Danios aren’t bottom-dwellers, so you are not constrained in terms of substrate selection. You only have to watch out for substrates that will support the plants you are planning to keep. 

Dark fine sand is a popular choice because it provides the benefits of being easier to clean and works well with most plants.

Tank decoration for Celestial Pearl Danio

Tank decorations such as driftwood, pieces of rocks and small branches are encouraged in the Celestial Peal Danios tank.

These elements help create additional hiding places, not to mention if done properly, can help turn the tank into an epic work of art.


A proper filtration system is highly important even for nano fish that do not produce a ton of waste. This is one of the keys to prolonging the lifespan of any aquarium fish. 

Like we discussed earlier Celestial Pearl Danio originated from plant laden fools. This will tell us that they are used clear water that is sure to contain a low amount of salt and minerals.  

To maintain properly filtered water for your Celestial Pearl Danio you can make use of a canister filter or a standard hang on the back (HOB) filter for their tank.

You can prevent the fish from slipping into the filter by fitting all the inlet tubes with sponges.

Water Parameters

The Celestial Pearl Danio is considerably hardy but still, ensure you keep their water significantly stable. 

It has been established that they perform best if kept in water with a temperature range of 73F to 79°F, a pH range of 6.5 to 7.5 and water hardness of between 2 to 10 dKH. 

These parameters can be maintained with the help of regular water tests, so investing in a qualitative test kits is highly recommended. 

Galaxy Rasbora (Celestial Pearl Danio)

Celestial Pearl Danio Food and Diet

Celestial Pearl Danio are omnivorous. Plants, zooplankton, algae, worms and small invertebrates are what make most of their diet in the wild. 

Fortunately, in captivity they aren’t picky eaters and readily accept different kinds of fish food. They are mostly fed commercially available pellets and flakes.

It’s recommended you choose qualitative ones so they can have a healthy diet.

It’s also a good idea to choose sinking pellets seeing as they mostly stick to swimming in the bottom half portion of the tank. This will ensure the food is getting to them.

Another thing to remember is they will require small food particles that can fit in their tiny mouth.

Galaxy Rasbora will also appreciate a varied diet as that will enable them grow to their full potential. Refrain from feeding them only one type of food like feeding them only sinking pallets for example. 

A way to achieve this is supplementing their diet with food such as grindal worms, moina, live daphnia, brine shrimp, krill. The krill especially is so important that it has been proven to improve their fins red coloration.

Observing the feeding habit of your Galaxy Rasbora will help you avoid overfeeding them. 

When fish are overfed, they put out more waste and will also leave residual foods. These two things will combine and mess up the water quality.

Celestial Pearl Danio Tank Mates

Most aquarium fish prefer hanging out with their kind before any other species. Accordingly, its recommended you have at least 6 Celestial Pearl Danio together before considering any other species. 

Size, temperament and water condition are what we consider in choosing a good tank mate for any aquarium fish. 

Celestial Pearl Danio are quite small and the rule of thumb is, do not combine two fish where one is big enough to swallow the other. 

However, in my opinion, size consideration should be more reserved than that. 

What I mean is, some species might not be big enough to swallow your fish but big enough to stress and out-compete them for food.

In light of this, I think any fish that grow much over 3 inches will not be a good Celestial Pearl Danios tank mate even if other parameters check out. 

Except in a case where they won’t be crossing each other territory completely. Like if one is a complete bottom dweller and the other is top.

In terms of temperament, Celestial Pearl Danio are for the most part peaceful and show no aggression to other tank mates (they only fight among themselves).

So logically, they should only be kept with peaceful non-territorial species. 

Lastly, you need to make sure any species you include in their tank can survive and thrive in their water condition. 

Neon TetraEmber Tetra, Killifish, Mollies, Endler’s Livebearers, Honey Gourami, Sparkling Gourami, Guppies and Cory catfish, work well as the Celestial Pearl Danios tank mates. 

Aquarium critters such as Red cherry shrimp and Amano shrimp have proven to work well with them as well.

Obviously, you have to upgrade to a bigger tank if you want to add any additional mate in their tank.

Galaxy Rasbora with Cherry Shrimp


Luckily breeding Celestial Pearl Danio is considerably easy. To start with, you need to know whether the female in the tank is ready to breed. When she is, you will notice that her body is darker in color and her abdomen will appear rounder.

It’s encouraged you feed them a good amount of live food to stimulate the spawning process.

Celestial Pearl Danio are egg layers and this is another reason to have a plant equipped tank. 

Naturally, female Galaxy Rasbora will lay her eggs around the plant because the water flow is usually low around that area. 

She can lay up to 30 eggs at once. It’s highly recommended you locate the eggs and move them from the main tank to the spawning tank as soon as possible.

Male Galaxy Rasboras don’t pass the chance of eating the laid eggs immediately they see them. The eggs are incredibly tiny so you may have to be careful to find them. 

The spawning tank should have a similar set up with the main tank with vegetation and everything.

After they are safely set in the spawning tank, you can expect the eggs to incubate in 2 to 4 days. Next, the fry will emerge and you can feed them micro foods for the first week.

Move on to feeding them baby brine shrimp afterwards till they reach adulthood.

Common Diseases

As I said earlier, these are rather new species and possibly many things are yet to be found about them. For this reason, scientists are yet to uncover any disease that specifically affects the Celestial Pearl Danio. 

This is not implying that they are not susceptible to any disease. Just like any other freshwater aquarium fish, they can get affected by other common diseases such as bacterial infection.

Fin rot is a disease that is known to affect the Galaxy Rasbora mostly. Remember I mentioned their males fighting habits over a potential mate. 

At times, fish involve in fighting can get their fin torn and when that happens they become highly susceptible to fin rot.

A quick way to identify this is by noticing the edge of their fins and if it is affected, the tissue in the area will appear discolored and infirm. 

Unfortunately, if not treated quickly the fins may even start to fall off.

The next thing that is known to cause fin rot is poor water quality. This is one more reason to be on top of their water quality. 

Ensure you monitor the water parameters diligently using qualitative test kits. This is one of the easiest ways to remedy fin rot.

Next is, use of antibacterial medication such as Tetracycline, Chloramphenicol in their water. These two measures will increase the chances of your fish full recovery. 

Commonly Asked Questions

In this part of the guide, I answer some of the common questions asked by hobbyists who are keeping or considering keeping the Celestial Pearl Danios.

Can Celestial Pearl Danio live with Betta?

Betta can thrive in the same tank conditions as Celestial earl Danio but that does not make it a good idea to combine the two.

For one, Bettas are very aggressive and territorial and they can grow 3 times the size of your Galaxy Rasbora.  

As such, they are more than capable of hunting down and murdering the little ones.

Some hobbyists have had the success of keeping these two while some haven’t.

It all comes down to individual betta you have. You might be lucky to have a rather reserved betta that won’t bat an eye at your Danios.

There is no telling which type you will end up with, so personally I recommend you don’t keep these two together.

How many Celestial Pearl Danio are in in a 5-gallon tank?

A previously stated, a good rule of thumb is allocating 2 gallons of space per inch of a fish. Celestial Pearl Danio has a maximum size of 1 inch which means you can only have 3 of them in a 5-gallon tank.

Celestial Pearl Danio with Angelfish

While Angelfish are for the most part peaceful they tend to have a habit of eating smaller fish. They can grow six times the size of Celestial Pearl Danio and they are more than capable of ravaging them.

Larger Tetras and Rasboras, are a more suitable choice for the angelfish if you want something quite smaller to their size.

How big do Celestial Pearl Danio get?

Celestial Pearl Danio has an average maximum size of 1 inch.


The Celestial Pearl Danios beauty is almost second to none. They are one of the best option out there for a hobbyist that want a nice touch of colors to their tank.

I hope you have realized by now that all you need to successfully keep them is a decently sized aquarium equipped with adequate plantation, decoration, a proper substrate and a qualitative filtration system.

Most importantly you need a water condition similar to their habitat’s.

You also need the correct ratio of male to female to lower the occurrences of fighting. You need a group of at least 6 of these little beauties before considering any other suitable tank mate.

If you want your fish to radiate those red and orange coloration even more, you have to feed them a high quality diet. 

On the plus side, they will be healthier and have a short at exhausting their full expected lifespan.

I highly recommend the Celestial Pearl Danio for hobbyists of all experience level. Though if you are a beginner, I stress you practice all the recommendations that will ensure a more peaceful tank.

In my opinion, that’s the part you are to most likely get wrong.

Please feel free to rich out if you have any question we haven’t covered or if you have any info you think will help improve this guide. We’ll be more than happy if you do.

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