Celestial Pearl Danio Stats InfographicThe Celestial Pearl Danio, also known as Danio Margaritatus or Galaxy Rasbora is a fish that has taken the internet by storm through a picture of it that surfaced more than a decade ago.

Many people thought that the picture was edited, thinking no fish that gorgeous could have been overlooked by the aquarium hobby for so long. The truth is, the area where the fish hails from had been off-limits to westerners for many years.

So in this article, we will make sure you will learn everything about the Celestial Pearl Danio diet, tank mates, breeding and more in case you want to put it under your caring wings yourself!

What Is Celestial Pearl Danio?

The Celestial Pearl Danio is a stunning fish that was discovered in late September of 2006 when its photograph went viral among tropical fish hobbyists on the Internet. Around this time, scientists were baffled about which genera the fish best fits into.

The species was originally called Celestichthys Margaritatus, which means “heavenly fish adorned with pearls.” Likewise, the Celestial Pearl Danio was initially categorized to be a member of the genus Microrasbora due to its resemblance to the Microrasbora erythromicron.

In late February of 2007, Tyson R. Roberts of the Smithsonian Tropical Research Institute finally released his formal description of the species and formed a new genus for it. Adding to that, Dr. Roberts suggested a new scientific name — Danio Margaritatus.

Celestial Pearl Danio Stats

Family Cyprinidae
Scientific Name Danio margaritatus
Common Name Celestial Pearl Danio, Galaxy Rasbora
Size of Fish 2 to 2.5 cm
Prominent Features (Males) deep midnight blue, dark red, pearlescent spots, black lines

(Females) blue-green with a bronze sheen, pearlescent spots

Diet Omnivore
Temperament Peaceful community fish that display intra-species aggression
Lifespan 3 to 5 years
Min. Tank Size 15 gallons for a group of 6 
Temperature Highly adaptable but warmer temperatures are preferred
pH Highly adaptable
Hardness Highly adaptable
Care Difficulty Easy


Celestial Pearl Danio Caring Tips for the Beautiful Looking FishWhen people saw the photo of the Celestial Pearl Danio that was circulating on the Internet, they assumed that it had been photoshopped. A chockfull of visual details are crammed into their tiny plump bodies. We find it difficult to put their beauty into words!

– Celestial Pearl Danio Size

The average Celestial Pearl Danio size is about 0.8 to 0.9 inches in length when fully grown. These small danionins will reach their maximum growth potential at about three months of age, which is also when they reach sexual maturity.

– Colors and Patterns

Males are absolute stunners with their deep midnight blue bodies speckled with pearlescent dots, thus creating the galaxy-like pattern befitting their name.

The ventral fins take on a vivid orange to red, creating a striking contrast to their deep blue bodies.

All their fins, save the pectoral fins, are outlined in midnight blue or black, as well. This pattern can be found twice on the tail fin.

On the other hand, the colors of the females look attenuated. Instead of a deep midnight blue, females appear blue-green with a bronze sheen.

The pearly dots are not as bright and their fins look a bit more washed out compared to the males. Some females may also have two parallel black lines on their fins but it is often a weaker version of the pattern seen in males. What’s more, their ventral fins are transparent.

Celestial Pearl Danio Care

– Celestial Pearl Danio Diet

The Celestial Pearl Danio diet varies greatly in the wild. In captivity, these fish will do just fine on high-quality crushed flakes and sinking pellets.

Despite their tiny mouths, these cyprinids have tiny conical teeth in their jaws, denoting that they are perfectly well-equipped to prey on small critters.

In addition to these commercially prepared foods, you will want to supplement the diet with protein-rich snacks, such as:

  • Freeze-dried krill
  • Newly hatched brine shrimp
  • Daphnia
  • Moina
  • Grindal worms
  • Small white worms

Celestial Pearls will eat everything with gusto!

– Water Parameters and Maintenance

There is little information regarding the water parameters of the species’ native habitat. According to some reports, the waters are just above neutral with minimal carbonate content and low conductivity.

Aquarists around the world have reported successful fishkeeping and spawns in both soft acidic water and hard basic water. Therefore, the exact Celestial Pearl Danio temperature and other parameters seem to be of no great concern if the water is kept pristine.

Water changes should be performed on a regular basis and dissolved organics should be kept low.

Here are the recommended water parameters for this species:

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

While the water parameters are not set in stone, many hobbyists have reported success in these ranges. The Celestial Pearl Danio might be best kept in an unheated tank similar to the way you would keep its cousin, the White Cloud Mountain Minnow.

– Health Risks

So far, there is no disease that Celestial Pearl Danios are particularly susceptible to except for fin rot.

This condition is often due to fighting between males. Injured fish are at a higher risk for getting this condition and even more so if the water conditions are far from ideal.

While fin rot is preventable, it can be difficult to clear up the infection and it is extremely contagious to boot. A secondary infection could follow immediately, killing the affected fish.

The good news is that you can treat fin rot at home using antibacterial medications if the condition has not yet progressed to advanced stages. You will have to quarantine the diseased fish and perform a 100 percent water change, among other necessary changes.

– Lifespan

With proper care, the Celestial Pearl Danio lifespan can reach up to five years in captivity. As with other species, several things can reduce their lifespan and that includes stress-inducing tank mates and poor water conditions.

Tank Setup

The species have evolved to take maximum advantage of their natural habitat. You should take note of this when setting up a tank at home.

– Tank Size

At an adult size of about an inch, Celestial Pearls seem to be well-suited for a desktop nano aquarium but you should only keep one male in such a tiny space.

Referring back to their intra-species aggression, stronger males will hound subdominant males. The losing males must have a place to get away; otherwise, they could get killed.

Several hobbyists who have kept these guys in cube tanks have reported that the alpha male may kill all rival males until he is the only one remaining. That is why we, at Badman’s Tropical Fish, recommend 15 gallons for a group of six Celestial Pearl Danios.

If you wish to increase the number of fish, a large tank will be needed. Aim for two gallons per extra Celestial Pearl Danio.

– Plants and Decorations

These beauties were discovered in heavily vegetated ponds. Despite slow water movement, the abundance of plants oxygenates the water and provides these little creatures with many places to hide in.

So, don’t skimp on plants; otherwise, these tiny cyprinids will display their discomfort by spending most of their time hiding. Being generous with aquatic plants keeps the squabbling males from seeing each other and wanting to attack each other.

Now, the question is — can you have too many aquarium plants? Not really. As long as you leave ample space for your fish to swim around, you cannot overdo plants.

– Substrate

Since you are aiming for a planted tank, gravel would be a wise choice for your freshwater aquarium. Gravel allows water to flow through it, thus preventing the buildup of bacteria and mold in the substrate that could sicken your fish.

Soil is not really necessary and it is up to you whether you want to use a special mineral-rich substrate. The most important consideration is the depth of the substrate.

If the substrate is not deep enough, the roots could get entangled and suffer from a deficit of nutrients. So, deep-rooted plants will need at least two to three inches.

– Equipment

For your planted tank setup, you will need the following:

A bubbling sponge filter or a power head-type filter could work, as bright lighting is vital for plants to thrive.


There have been several shots of Celestial Pearls swimming together in a large group. These photos may have prompted fishkeepers to obtain this species. Now, the question is — do these fish truly exhibit schooling behaviors, or were they just crammed in the dealer’s display tank?

– Are Celestial Pearl Danios a Schooling Fish?

No, the Celestial Pearl Danio is not a true schooling fish. Schooling behaviors are rare once the group settles in their new tank. Females may congregate every so often but you would not really see them display schooling behaviors in a classical sense.

– Are Celestial Pearl Danios Aggressive?

Indeed, they are. For a creature so tiny, it is surprising to know that males can be so brutal. Males spend most of their time wooing females, which often involves a ritualized circular dance. Skirmishes take place when there are rival males nearby and weaker males will be harassed to the point of death.

Due to this intra-species aggression, it is advisable to keep these fish in a spacious tank so that the losing males can swim away from their tormenters with no trouble.


The first successful captive breeding took place just a few weeks after the Celestial Pearl Danio was discovered in the wild. That’s when it was observed that this species spawns almost daily in both wild and captive settings.

– How Do Celestial Pearl Danios Breed?

The actual spawning occurs only when a male hovers above the spawning medium, with his body at a slight head-down angle to the bottom to show off its saturated colors.

If a female is interested, she will swim over to the male and initiate spawning by shoving her head against his anal fin. Both will dive into plants or mops, releasing eggs and milt.

The pair would then break apart and go separate ways. No bonded pair will be formed; both sexes will spawn with multiple mates.

– Do Celestial Pearl Danios Lay Eggs?

Yes, the Celestial Pearl Danio is an egg scatterer. A large female can lay a dozen to 30 Celestial Pearl Danio eggs in a single spawning event. As with other egg-scattering fish, there is no paternal care taken here. The eggs will fall off and adults, including the parents, may feed on them.

– How Do You Raise Celestial Pearl Danio Fry?

You will need to separate the eggs from the adults using a spawning grate, such as a plastic needlepoint canvas, followed by setting it up with plants or acrylic spawning mops. Fertilized eggs are only lightly adhesive; thus, they fall to the bottom rather quickly.

Fertilized Celestial Pearl Danio eggs will hatch as early as the third day if the water temperature is kept at 76 F. Newly hatched fry are dark in color and these little buggers will spend most of their time lying on the bottom. So, don’t be confused or mistake them for being dead.

Depending on the temperature, the fry will be up and swimming in two to four days. The baby fish will eventually lose their dark coloration and take on a lighter silver color.

We suggest feeding the free-swimming fry with liquid fish food and crushed commercial fry flakes for a week before introducing newly hatched brine shrimp. Once the baby fish develop orange to pink bellies, they are ready to take on worms and other live foods.

Growth will be rapid from this point onwards. Juveniles will start taking on their adult coloration at about nine weeks of age until they reach their maximum size at about three months.

Ideal Tank Mates

Choosing Celestial Pearl Danio tank mates is a breeze. Highly adaptable, you don’t have to worry that these little guys might not share the same water requirements with the species you have in mind.

Size is the main thing you need to consider because even large peaceful species may pose a problem; big fish may view your little danionins as food.

So, here are some of the best tank mates for your Celestial Pearls:

When adding a few of these compatible fish, you may need to increase the size of your tank to accommodate them. Learn about each species to ensure their needs do not cause conflict among other fish.

How Many Celestial Pearl Danios Can You Keep Together?

You may start with five to six Celestial Pearls in a 15-gallon tank with more emphasis on females than males. Having more females than males lowers the risk of intra-species aggression.

Frequently Asked Questions

Celestial Pearl Danio Care, Breeding and Tank Setup

1. Where Are Celestial Pearl Danios From?

The Celestial Pearl Danio inhabits a series of plant-laden pools in the Shan Plateau that were created by seeping groundwater and overflow from springs.

Small populations can also be found in flooded grasslands and rice paddies in the mountainous area around the town of Hopong east of Inle Lake at an elevation of 3,400 feet above sea level.

Water movement is low and the ponds are open to the sun, thus breeding a rich variety of aquatic plants that offers their dwellers refuge.

The water would heat up rather quickly during the hot summer months as they are shallow. Thankfully, plants like the Hydrocharitaceae provide fish shade.

2. Is the Celestial Pearl Danio Extinct?

No, it is not. In February 2007, just a few months following its discovery, the Myanmar government banned exports of the said fish to prevent rapid decline. The ban was lifted after Myanmar officials discovered populations of the fish in five more locations in Hopong.

The rumors about the Celestial Pearl Danio being pushed to the verge of extinction were exaggerated. This species is far from being “endangered” or “extinct” as the locals are trying their best to keep the fish populations strong so they have a source of income for many years to come.

3. How Do Male and Female Celestial Pearl Danios Differ?

Apparently, the Danio Margaritatus exhibit sexual dimorphism. As stated earlier, males display deeper hues of blue and red. The dark outlines and pearlescent spots are more prominent compared to females.

During the spawning season, courting males will show off a deeper red coloration on their stomachs. This coloration may have fueled some hobbyists to exclude females but keeping a ratio of males to females is key to keeping a healthy group.

4. Danio Margaritatus vs. Microrasbora Erythromicron

Some people have also mistaken the Celestial Pearl Danio for the Microrasbora Erythromicron, commonly known as Emerald Dwarf Danio and Emerald Dwarf Rasbora.

The Celestial Pearl Danio resembles the Emerald Dwarf Rasbora more than any other species due to their size and colors. However, instead of pearly dots, the Emerald Dwarf Rasbora has vertical bands.

Regardless, both species make for an impressive display on a planted tank.         


Since its discovery, the Celestial Pearl Danio became one of the most coveted fish in the aquarium hobby due to its enthralling appearance since its discovery. The fish has been sold under the trade name Galaxy Rasbora, although these cyprinids are not really rasboras.

Furthermore, we spent our article helping you make sure it gets the best care it possibly can, so here is a summary of all the information we shared:

  • As Celestial Pearl Danios are a highly adaptable species, the water parameters are not as important as the water quality. Keep the water pristine and well-oxygenated
  • Celestial Pearls will eat anything from live foods to commercial fish feed
  • For ornamental purposes, you can keep them in a community aquarium with other small fish, such as mollies and guppies
  • The more plants they have to hide in the tank, the more likely Celestial Pearls feel confident enough to be out in the open
  • Albeit considered a peaceful fish, males would often fight. Squabbles between males can cause injury and sometimes, death
  • It would be best to keep these danios in a species-inclusive tank with no other fish if you wish for them to breed
  • Celestial Pearls are a cinch to breed. But as these fish are egg-scatterers, it would be best to keep the breeding pair in a separate tank and remove the adults right after the spawning ends
  • Their love for plants makes them the perfect fish for those who like aquascaping. However, you don’t want to place a group in a desk tank due to their intra-species aggression

We do hope that this article has provided you with everything to know about caring for the Celestial Pearl Danio.

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