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 hobbyists have quickly adopted and fallen in love with these little Danios.

They are well suited for tanks that are packed with vegetation and other freshwater 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.

Celestial Pearl Danio Fats & Overview

Celestial Pearl Danio

Care Level:Medium
Color Form: White spots along the body with red coloration on the fins
Lifespan: 3-5 years
Size: Up to 1 inch
Diet: Omnivore
Family: Cyprinidae
Minimum Tank Size: 10 gallons
Tank Set-Up: Freshwater: highly vegetated and shallow
Compatibility: Peaceful communities

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 the 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 outcompeted 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).

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

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 the neon tetra. 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.


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 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 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

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.

About Robert 386 Articles
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. Adonis Roberts says:

    I have 3 and just ordered 6 more. They are tiny and fun.

  2. B-Rad says:

    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.

  3. Andrew waggett says:

    Have 6 of these with guppies, tetras, discus and clown loaches. Fit in fine, discus leave them alone, no snacking. Great addition to the tank

  4. Ed says:

    Thank you for your articles!

    We have two groups of celestial danios. The first group of 9 are mostly greenish, with the males being more blue. The second group of 15 is darker overall, and the males are almost black. Striking difference in appearance, although exactly alike in every other way. Two different breeders, we guess. Both have fins more orange than red and both spawn almost daily, usually within an hour of turning the lights on in the morning.

    Due to the lower population density, the smaller group does best with actually completing spawning. The larger group contains so many males (6m/9f), they spend most of their time chasing each other off and the time it takes for one of them to finally pin one of the females is much longer and often interrupted. I think an ideal number is no more than about three males to about ten females. Only a small number of females are ripe at any given time and so as they rotate through, any males are concentrated on only the few ready females. As it is, we get plenty of spawning, but it’s a meelee…

    They are sporadically available here (Maryland) and you really should get them when they first arrive at the shop. I typically see them look good upon arrival, but they are tiny, probably 1/2″ long and very limited as to what they can eat. As time goes on, the remaining fish in the tank lose condition and are often very skinny after a couple weeks, like they cannot eat most whatever they are being given. I had been feeding our little ones chopped up blackworms and brine shrimp, and ‘First Bites’ powdered food. I had the dark batch about two weeks and when I went past their original tank in the store, I could see the remnants were half the size of ours and stunted-looking.

    Because we have corys in the tanks that have learned to follow the spawning celestials around, and because any surviving fry would be at the mercy of the adult celestials, which hunt intensely almost all of the time, we have yet to see a baby celestial. Just as well, the cory population kind of exploded on us and we don’t want even more tanks.

    We also have an increasing number of about 50 cherry shrimp that reproduce freely in the community fish tanks and it seems that if the shrimp can get to about 1/4″ long, the celestials don’t bother them. We see this in both celestial tanks. You can see the celestials coming over and sizing them up, but then turning off. When we feed adult brine shrimp to the celestials, they are borderline too big for them. They have to work on one for awhile before they get it down and these brine shrimp are much more ‘feathery’ then the cherry shrimp of the same size.

  5. Ed says:

    A quick update (11-23-19):

    Our dark batch of celectials have produced several groups of babies with individuals that have survived in a heavily planted 40 gallon breeder tank.

    We have had a case of “give and take”, where several barely mobile babies will show up, looking like a hair with eyeballs, then, within a day or two, they’re all gone but one or two. I have a horizontal beech limb in the tank about 2/3rd of the way up toward the surface, with several clumps of various mosses, some well infested with hair algae, spaced along it’s 24″ length and the babies show up in and around the moss. As those one or two survivors grow, we will see more tiny fry appear, then most will disappear again, leaving one or two.

    As a result, I currently have 11 fry between 3/8″ long and barely big enough to see, probably at least 4 or 5 age classes. The largest ones are getting their color and are moving about among the adults with impunity. The smallest three have been in there a week and seem to have learned to avoid the adult fish, so they’ll probably make it too.

    I have several spawning sites in the 40-B tank; several Java Moss clumps tucked into rock crevices near the bottom, a group of small ‘Wendtii’ crypts planted along a sumberged beech limb lying on the bottom, and a cluster of Java Ferm mounted on a piece of driftwood about 8″ long. The root mat around the convoluted strip of driftwood is very thick and if I had to guess, I’d say most of our survivors came up from that impenetrable tangle.

    The odds against survival in a community tank (Celestial Danios, Corydoras, Otocinclus & cherry shrimp)are incredible:
    1) Any following males not actually involved in the spawn will quickly grab any loose eggs and look carefully for more.
    2) The corydoras I have for cleanup know what spawning time is and will stage themselves at strategic points and eat the eggs as soon as the fish move off. I have larger size gravel in known spawning areas, but the corys are like little vacuum cleaners. I can distract them with blackworms if I need to, but they are pretty persistent.
    3) The shrimp, corys and otocinclus constantly search the bottom for anything edible, so most eggs that do happen to make it past the spawing/feeding meelee, as well as fry still working off a yolk sac, get snuffled up. I know the Otos are supposed to be vegetarians, but that is not strictly the case. The shrimp will eat anything and will often catch a blackworm and then fight to keep it.
    4) The adult Celestials, most notably the adult females, hunt constantly and with great focus. I have wild daphnia, cyclops, planaria and scuds in the tank and the fish hunt for them, as well as for their own fry. The adult female Celestials literally worm their way through the moss and algae searching for prey.
    5) The newly mobilized fry are microscopic and finding food for them can be challenging. I found that the “First Bites” I was recommended is a little too big and they can only eat a very few tiny chips of it. I may have lost some of the early fry because they couldn’t get enough to eat. I have been using a fine powder consisting of krill and spirulina they they eat readily. Once they are a couple weeks old, they can eat more of the ‘First Bites’ and frozen daphnia.

    • Curt says:

      Wow good info. Thanks

      • Kerry Buchanan says:

        Very helpful. Thank you!

    • Spira says:

      This is awesome! Thanks so much!

    • Xmegatron10 says:

      Put a pair of pearl danios with a single male clown killifish of flagfish

    • Lynn Robson says:

      Feeding fry as small as that is problematic. I hard boil an egg then mash the yolk and liquifry it. It can be drip fed from a pipette or by a syringe

    • Thank you for that information. I’m trying different ways of breeding them. Haven’t had a huge success yet, but I’m learning. I have about 20 fry that I’m babying right now. I feed them powder.

  6. Ben says:

    We have a 45 litre tank currently with 3 Platty, 4 Neon Tetra and 2 Danio a couple of Netrite Snail and 4 ghost shrimp, the tetras and danio are pretty hard to tell if they are male or female, but the platty i know i have 2 female and 1 male, i now have 9 platty fry and i was concerned that they would be eaten from reading various articles but they were left alone straight away and are growing at a rapid rate!

    Would the celestial be a good addition? I LOVE the danio’s and these are stunning!

  7. Kerry Buchanan says:

    I have just bought eight of these beautiful little fish from my local fish shop. I tried to get more females than males, but I think I ended up around 50:50 (although they are tiny and I am long-sighted so can’t be certain!).
    I have them in a heavily planted tank, by themselves (might add some shrimp or a nerite snail later) and they are truly beautiful, but still quite shy.
    I’ve tried Tetra Min flakes (ignored, even though I crumbled them into tiny pieces) and Tetra microgranules, but no interest in either. Maybe they need more settling in time, though. I have some frozen bloodworms that the mixed tetras in my main tank devour as if they’ve been starved (they definitely haven’t!), but again, no interest.
    My lfs is generally very good and the staff both passionate about their fish and knowledgable, so these guys are in great shape despite having been there for a few weeks now. I just have to keep them that way…
    Questions: how vital is a pH of >7? Mine is refusing to budge above 6.8-6.9 and I’m anxious it won’t suit them. Other water parameters are spot on and the water is stable at 77 degrees.
    I feel like a first-time parent! The anxiety!

    • Spira says:

      Did you ever get you CPD to eat? They can be fussy at first. Mine will go crazy for baby brine shrimp! They also eat eat tiny pellets but takes them a few tries, and only certain brands. They also like frozen blood worms, but I have to chop them up to 1/3-1/4 the size they come in.

  8. Sharon Roberts says:

    I bought 2 a few months ago and was lucky enough to get a Male and female. There are 5 ember tetras in the same 10 gal. tank and some cherry shrimp. I got three eggs out of the moss and raised three babies in a 3 gallon algae covered tank. I fed them powered food until they were a couple weeks old and could eat baby brine shrimp. They are now with their parents and the ember tetras in the 10 gal tank almost grown. It took several months for them to get this big. I was able to get a couple more eggs and raise 2 more babies in a breeder net in the same tank. These two are now growing up in a five gallon tank with some cherry shrimp. Then I got some more eggs and have 6 more in a breeder net in a different tank. They are still tiny. Unfortunately my water is very hard, but they seem to be thriving even though the pH sometimes gets as high as 8.2. I plan on putting all 8 of the newest babies in a separate tank. Now, thanks to your article, I know it should probably be bigger than a 10 gallon. Maybe a 20 long? They have some growing up to do first.
    Thanks for the valuable info. I have only been keeping fish a year. Can I put Phoenix Rasboras in the same tank? I just got 12 who are in quarantine.
    The CPD’s seem a bit rough, but maybe that is just with each other. They don’t harass the ember tetras. Also I have no idea of the sex of the 11 babies. I hope there are a lot of female, but even when they are tiny fry a couple will break off and “fight.” This might mean those are male. Thank you.

  9. DJ says:

    My son bought 9 fish and put them in a 20 gallon, with some white cloud. Damned if the little buggers decided to spawn. We got over 30 fish within a week. He didn’t have the room, and I inherited them. Have had them in a 30 gallon tall, with white clouds, for 3 months, and now have reduced the white clouds, and added 7 platties. My eyes are bad (caterachs sp)so I can’t see the colours, but they have seemed happy enough. I’m here to learn more about them, because I have a Plecko that needs a home where he won’t be harassed. Sounds like eventually I can put him in with the Celestial Pearl Danios, at a higher temperature: 76-77 degrees. Later I’ll buy another 30 gallon long if they get along. BTW I’m getting back into having fish, after 45 years. Things have certainly changed a lot.

  10. Crony says:

    I’d added 12 of em to my 13 g (50l) shrimp tank to stop the overbreeding of shrimp. Sadly 2 males were killed by alpha/s? . Now i have better ratio of 6 females to 4 males and they seem more chilled out.
    WARNING: they eat only food WHICH FLOAT in the water column so feed flakes but many times small amount or 🙁 small live food
    (MY CYCLE OF FEEDING THEM tetramin flakes, microflora (moreless algae), crushed biomax (originally for shrimp) and live daphnia + naturally shrimplets.
    BREEDING: they will breed all the time, but they will eat all their fry (need to collect eggs from spawning moss – adjust the temperature for fry to at least 24°C (idn °F) and feed them infusoria or powdered yeast for 4-6 days
    they need to be separated from parents till 1 cm +

  11. Blake Hunt says:

    I have three in a ten gal and they will take care of snail egg clusters. My tank was originally a shrimp tank but the snails were making a lot of waste, so these guys and an assassin snail fixed that. Its nice to have something a little more energetic and the shrimp are more active now.

  12. Kat says:

    Looking at getting a few of these for my planted 10gal, thanks for the info! Anyone know if I’d have any trouble keeping a few cherry shrimp as tank mates?

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