Celestial Pearl Danio are low maintenance, ornamental fishes from the shallow waters of Myanmar, and are best suited for aquariums. 

It is a small and beautiful fish that doesn’t require much experience to handle, and hence earn a quick sale by many aquarists.

These are commonly called Galaxy Rasbora because of their body’s peculiar design, which looks similar to that of a galaxy.

Lets’ find out more about their appearance, food preferences, reproductive cycle, and tank necessities.

About Celestial Pearl Danio

Quick Species Facts
Scientific Name Danio Margaritatus
Other Common Names Fireworks Rasbora; MicrorasboraSp. ‘Galaxy’; Pearl Danio
Family Cyprinidae
Origin Myanmar
 Average Lifespan 3 to 5 years
Max. Length 2.1 cm
Type Peaceful; Sometimes nipping is seen
IUCN Red List Considered Threatened; Data Deficient

Origin & Habitat

Galaxy Rasbora are endemics of Hopong town area, situated in the eastern side of Lake Inke, Myanmar. They are exclusive dwellers of Nam Lang and Nam Pawn, the tributaries ofSalveenriver that comes from China.

Though it prefers freshwater habitat but can also thrive for long in small ponds with lots of vegetation, that fills by ground water seepage, and rain during springs.

How Long Do They Live?

Celestial Pearl Danio lives a very short life and on an average it dies out by three years.

While facing extreme environmental conditions, and difficulties in getting nutritious food and defending itself from predators, this fish can complete five years of life.

If you wish to pet them for long time, then maintain water parameters and provide high quality diet.

Engaging it with small sized friendly companions in the tank will keep them stress-free, enhance their life.

Size & Appearances

These fish species are quite small. Their average length lies around 0.8 inch, if good conditions are met.

Their body has a deep blue hue with distinct pearl-like or white spots. The fins are deep red with two to three black stripes.

The red fins display a contrasting effect against the blue skin so they are easily recognizable during buying.

Their mouth is small & blunt while eyes look quite big. The body is significantly rounder than generally small fish of its size.

Gendering Them

It is a clearcut observation to distinguish between male and female Celestial Pearl Danios. The task simplifies as they age. Here are some of the characteristics that helps define the gender of the fish.

  • Males are comparatively smaller than females.
  • The body of a male is angular shaped, while females have curvilineal structures even when not spawning.
  • The male has a prominent deep blue color while the female has a greener hue to their body.
  • The males display bright shades while the female look sluggish.
  • The males have orangish fins while females have black spot over its anal fin.

Availability and Price

These fishes are pretty attractive due to their contrasting color, small size and fun-loving nature. They are highly in demand by newcomers in fish keeping since they do not require excessive care, and live sufficiently to give all-round experience to the owners.

They are commonly available in the market and can be purchased from many local and online shops. The price can vary depending upon many factors such the age or color but generally is in the range of $4 to $5. Few sellers offer discounted price on purchase of pairs or multiple fishes together.

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Tip: It is suggested to buy a minimum of 5 – 6 of galaxy rasbora (preferably in pairs). This will enhance confidence & longevity of the fish.

Care Guide

Quick Care Facts
Care Level Beginner
Breeding Effortless
Social Temperament Friendly
Diet Omnivorous

What Do They Eat?

Celestial Pearl Danio have an omnivorous diet. While in wild, they usually endure their living over small worms, invertebrates, fishes, critters, algae, or aquatic plants.

The fish is easy-going and consume almost anything offered, but they should not be overfed, probably not more than two times of equal time difference.

Since they have little mouth opening with small teeth, you can offer them anything that is crushed or minute in size, and reaches the bottom where it is consumed by it.

Here is the list of preferred items for the rasbora.

  • Pellets&flakes (avoid lower quality)
  • Frozen or Live Worms- Grindal Worms, White Worms, Bloodworms
  • Invertebrates
  • Small Crustaceans- Dapnia, Artemia, Moina (improves their coloration)
  • Shrimps- Brined orFresh
  • Plankton- Zooplankton &Phytoplankton
  • Vegetables- Cucumber, Boiled Carrot, Plantains, Fresh Spinach, etc.

Temperament & Behaviour

Galaxy Rasboras’ generally stay peaceful and do well in both big or small groups. They are usually seen near the middle and bottom part of the aquarium.

They do not tend to hide under the bushes or other objects. It is observed that celestial pearl mostly swim around in groups, may be because this boosts confidence in them, and tackle their introvert nature.

Though being shy, but once it settles down well, and gets familiar to the environment, you will observe them moving quickly around other species that behave harmoniously.

An equal number of male and female are kept together to maintain peace as often the males will show aggression and fight with one another during the breeding period. Having enough females helps avoid that.

Reproduction in Celestial Pearl Danios

Mating and breeding of Galaxy Rasbora isn’t very difficult. They can breed all year round; they don’t require a specific season for breeding.

If male and female species are put in tank, they will start breeding by themselves, given the water temperature is optimal.

Fact: These fishes can start reproducing as early as three months of age, provided they get enough protein-rich feed like shrimps or worms, and suitable water parameters.


Though they are ever-ready for reproduction, but you can make few arrangements to make the process manageable.

Get a separate tank with a spawning mop for eggs collection. Once you induce the pair in the tank, the males will eventually find the appropriate location for spawning, which is usually java mosses or artificial mops.

They perform unique body movements to attract the females, when the body is tilted downwards and shaking. The females follow them towards the mosses.

Quick Tip: If possible, you should induce one male with two females, as the male can mate simultaneously with both, and each female gets sufficient time to get ready for another session.

Egg Spawning and Hatching

With proper conditions in the tank, such as warm temperature, and still water, the fish will start spawning. During this time, the color of females start darkening.

The optimal temperature for eggs to hatch lies around 24 to 25 °C. After sufficient incubation period of 3 to 4 days, the eggs will hatch.

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Remember to remove the parents after the eggs have been fertilized so that they don’t eat their own eggs or hatchlings.

Author Note: Galaxy Rasbora can mate constantly, and on an average, they can lay 20 – 30 eggs per day.

Maturation of Younglings

The fry are dark in color which is a camouflage technique to prevent them from getting eaten by their own parents or other fish.

After hatching the fry takes about five days, when they can comfortably swim and eat fry powder food, paramecium, or spirulina.

Just after two weeks of hatching the juvenile can consume baby shrimps, and now they start growing faster.

Thejuvenile rasboras will start to exhibit adult features, like shape and vibrant patterns, after growing for about three months, when you can deduce their gender.


  • White Spot Disease (Ich or Ick)
    This disease is caused by a water parasite known as Ichthyophthirius Multifiliis. It causes small white spots all over the fish body and each of them is a parasite on its own.
    Treatment– Separating the fish into a different tank. Zinc-free malachite is used in the tank water to prevent the further spreading of this disease. Parasite specific antibiotics can be used for cure like- toltrazuril and imidocarb.
  • Fin & Tail Rot
    It can be caused by fungus or gram-negative bacteria such as Vibrio, Aero monas or Pseudomonas spp. Responsible for rotting of fishtail which starts at the tip of the fins and progresses to the base, rendering the fish unable to swim or move in the water.
    Treatment- Transferring the fish to a quarantine tank and administering broadspectrum antibiotics.
  • Fungal Infection
    A type of fish fungus known as Saprolegnia causes this. Symptoms are- Cotton-like fungal growth on body and eye discoloration.
    Treatment– Putting specific antifungal medication in the tank, along with bath salts to help with recovering.

Author Note- Be wary of the water quality as these fish are sensitive and prone to infections. Make sure to change or replenish the tank water routinely.

Tank Care

Quick Tank Facts
Water Temperature 73°F to 79°F
Minimum Size 38 litres
Water Hardness 2 to 10 dKH
pH Level 6.5 to 7.5
Minimum population 5-6

Ideal Tank Size

Galaxy Rasbora are small species and it doesn’t require a massive tank.

The minimum recommended tank volume to keep a school of 5 – 6 of them is 10 Gallons.

This is a comfortable& adequate swimming space for fish of this length, and number together.

Tank Setup

Their natural habitat consists a lot of aquatic plants such as Canadian waterweed which is flowering plant found in lakes and ponds, andthey use it as a hiding spot.

So, equipping the tank with water weeds and Java moss can be a good choice. Java moss also shelters different kinds of protists (bacteria), which is an acceptable source of food for the fish.

Celestial Pearl Danios are not nocturnal species. They live in low-depth region, where sunlight can partially penetrate, and they receive adequate radiance throughout the day.

Thus, you should install white LEDs or dim halogen lamps in the tank, which creates optimum visibility, enhance their colors, and fulfil their natural needs of lights.

  • Substrate
    Substrate used for Celestial Pearl Danio should be sandy to mimic their habitat. Regular or fine dark sand could be used to achieve that surrounding.
  • Filtration and Other Apparatus
    Use of filters is recommended as they are sensitive and cannot tolerate unhygienic conditions.
    Air pumps with sponges can also be used which have a gentler flow because they prefer waters with less turbulence. You can even opt for no pumps and still wouldn’t make much of a difference to them.
    A small heater can also be used in tank to maintain a slightly warm temperature and make it feel more like their wild habitat.
  • Decorations
    You can use big stones with large holes in it for the fish to hide in them. Logs or driftwood will also fulfil the purpose.
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Water Parameters

Galaxy Rasbora possess strong survival tendencies as their natural habitat varies from rivers to ponds and lakes. But while in captivity, it requires proper care and discipline, which will keep them healthy and stay alive for long.

The best suited water temperature for them is around 20°C to 26°C, while the hardness should be kept between 2 to 10 dKH.

Celestial Pearl Danio prefer slightly acidic water but can thrive well in pH range between 6.5 to 7.5. If there is too much fluctuation in the pH, different kinds of salts can be used to balance it out. Deionized water can also be used to dilute the pH.

Author Note- Be careful while adding salts in water, you wouldn’t want to alter the pH too much or it could lead to various disorders like acidosis or alkalosis.

Compatibility With Other Fishes

They do well with fishes of similar size. In general, they are rather timid and putting big fishes could result in their stressing out or even worse, getting preyed upon.

You can introduce aquatics with contrasting colors that compliments the shades of Celestial Pearl Danio.

You can choose some from the option given below. They can live safe and friendly together.

  • Neon Tetras
  • Guppies
  • Cory Catfish
  • Gouramis
  • Killifish
  • Corydoras
  • Mollys
  • Cherry Shrimps
  • Snails


Q. Do Celestial Pearl Daniosnip on fins?

Yes, nipping on fins can be seen if slow moving fish such as angelfish, bettas, etc. having long fins are kept with them. However, this behavior can be avoided if they are put in bigger school so that they won’t bother the other fishes.

Q. Can they live with Bettas?

Both have same water parameter requirements and both have similar size and temperaments. Soyes, they both can be kept as good companions with to each other. But keep in mind that Pearl Danios can sometimes nip on the fins of bettas.

Q. Do Celestial Pearl Danios jump out?

These species like to stay hidden under vegetation, and come out for food. You are not likely see them jumping out of the tank, unless they get scared and panic.

Q. Are Celestial Pearl Danios bottom dwellers?

Yes, they are bottom dwellers but are also found swimming at the middle section of the tank. So, while feeding them, make sure the food particles sink and reach to them.

Q. How many Celestial Pearl Danios should be kept in a 5-gallon tank?

In a 5-gallon tank, a group of 5 to 6 can be kept together but it will just be enough space for them. It is recommended to use at least 10-gallon tank for a group of 5 to 6 fishes for ample swimming area.

Q. Are Celestial Pearl Danios schooling fish?

Though they are considered a schooling fish but observers have found out that they usually start moving independently, once they get adapted to the environment.  A common behavior of schooling fishes is commonly missing in them after some time.

Conclusion: Should We Get Them Home?

Celestial Pearl Danios are a great addition to a household aquarium. They are mesmerizing beauty, and notorious with their fin-nipping behavior. They are easy to care for, and eat all kinds of generic fish food.

As it’s a beginner level fish, you don’t require a lot of experience to manage them. Breeders do not require a lot of setup as mostly putting them in a tank with suitable temperature and pH is sufficient to begin spawning.

In short, if you want your tank to be as colorful as possible, a group of Celestial Pearl Danio would add a lot to it.

About the Author

Shelby Crosby

Shelby is a passionate fishkeeper who has been writing about fish for over 5 years. She is a pro aquarist and holds a BSc Honors Degree in Wildlife and Fisheries. She creates her own beautiful aquarium layouts and loves to share her knowledge of tropical fish with other hobbyists.

Career Highlights:

  • Has worked with several aquarium manufacturers as a consultant
  • Organized and hosted workshops on freshwater fish keeping at retail stores, educational facilities, and libraries
  • Released content for the amphibian community through her writings

Educational Highlights:

  • BSc Honors in Wildlife and Fisheries in 2011 (University of Northern British Columbia)
  • Completed her undergraduate thesis on the effects of zoochlorella supplementation on the growth and health of fish.

Writing Experience

Miss Crosby is a Freelance blogger; many of her articles are posted online on various blogs. She has also written a few short articles for "Tropical Fish Hobbyist Magazine" in the past. She is a regular contributor to FishParenting.com. Her education, first-hand experience with fishkeeping, and in-depth knowledge in aquaculture make her one of the most competent writers in the industry.

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