Celestial Pearl Danio: Care, Breeding, Diet & Behavior

Celestial pearl danio is a vividly colored, tiny cyprinids found in Southeast Asian seas. They are not hostile in any way, and they like swimming in shoals.

Because they can only reach a maximum length of around 2.5cm, a small fish tank is suitable for them. They do best in a tank with a slow flow rate, and their tank should be filled with plants and other objects that provide hiding places.

Even though they’re little, they’re never insignificant in the aquarium. For starters, they are brightly colored and quite active. So there’s never a dull time in the tank with them.

This page goes into great detail about their behavioral patterns, food habits, lifestyle, and tank mates. Again, you’ll learn a few care recommendations as well as how to breed them in your home aquarium.

Celestial Pearl Danio Overview

Celestial Pearl Danio Overview

Family: Cyprinidae
Origin: Myanmar
Temperament: Peaceful
Size: Up to 1 inch
Minimum Tank Size: 10 Gallons
Diet: Omnivore
Care: Medium
pH: 6.5 – 7.5
Alkalinity Levels: 2 – 10 dGH
Temperature: 73°F – 79°F

The Celestial Pearl Danio or Galaxy Rasbora, scientifically known as Celestichthys margaritatus, is a stunning pint-sized fish that was initially discovered by Thai aquarist Kamphol Udomritthiruj in 2006. Since then, it has gained a lot of popularity and has been given several other names.

Habitat and Distribution

Small, shallow, and densely planted ponds in Southeast Asia are home to this unusual species of fish. The species was initially discovered in Hopong Village, Burma, in a tiny plant-laden spring-fed pond. Celestial Pearl Danio can only be found in small ponds in mountainous areas in the villages around Hopong, about 1040 meters above sea level in Myanmar’s northwestern region. The area is largely grassland, with plenty of sunlight and high-quality aquatic plants.

The water where the species lives reaches 95 degrees Fahrenheit in the summer and practically freezing in the winter. For numerous years, westerners were barred from entering the Hopong region where the fish was discovered, and several additional species were eventually identified in the same location. Since then, these fish have been discovered in waters connected to the Salween River throughout Southern Shan and across the Thai border in Northern Thailand.

The species was on the verge of extinction in 2007 due to overfishing. Due to the ease of breeding, aquarists were able to breed the species under tank conditions, eliminating the need for wild fishing.

Physical features

You’ll fall in love with these fish’s heavenly beauty, which includes wonderful hues all over their bodies, pearl-like markings on the sides, and stunning red fins. Any backdrop may be brought to life by a bunch of Celestial Pearl Danio. The coloring of these fish’s fins, which feature two parallel lines of red or orange depending on their sex, is what sets them apart.


Males of this species are slimmer and have a more brilliant hue. The pearlescent specks are placed in a pattern that is plainly apparent on the flanks, and they have a deep dark blue tone overall. Their fins and belly are likewise striped in vivid red. On the backs of males, there is a distinct flash of red that goes all the way from the head to the dorsal fin.


Females get rounder and larger in form while they are pregnant. They have a lighter tint than their male counterparts, who have a bright blue shine. The iridescent dots aren’t as brilliant in females, and the fins are a pale orange color. Only a small percentage of females get an orange hue in their stomach. At the start of spawning, females are supposed to grow a black mark in front of the anal fin.

Fish have an unusual physical form, with their body length being around three times their height. The blood arteries may be seen through the gill plates, which are virtually transparent. Male fishes are given precedence when people buy them for their aquariums because of the noticeable variation in colors between males and females. Having all-male fish in the tank, on the other hand, can lead to a fight, therefore it’s best to have an equal number of males and females in the tank.


In stable aquariums, the Celestial Pearl Danio can live for 3-5 years.


This species of fish is a maximum of 1 inch from head to tail in size


Because this kind of fish lives in groups, you may keep a group of 6-7 fish to keep them active. These fishes are calm and serene in nature, and they coexist alongside groups of Mollies, Killifish, Tetras, and Guppies that have similar behavioural patterns. Having fish of the same species or origin is also a good idea because their activity patterns are almost identical.

These fish are believed to get along well with Neon Tetras, which prefer to stay on the surface of the water. Celestial Pearl Danios live in a tranquil community tank with many other species, making them suitable for it.

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If you opt to have a variety of schooling species, your tank will require more water per fish. To lessen their timidity, these fish should be kept among other fish of similar size. The Celestial Pearl Danio will be scared and outcompeted for food by larger, more aggressive species.

The majority of males’ time is spent pursuing females and battling with competing males. Male fights are nothing to be concerned about; they are mainly ritualized, and the weaker men are unharmed if they simply swim away.

If they can’t get away from the fight, powerful males can use their fangs to attack lesser males. If there are a lot of males, it’s best to put them in a larger tank with a lot of plants to discourage conflicts. The male fishes will have a nice hiding spot in the tank if there are plants in the tank when they are battling for females.

It’s also worth noting that these fish have a proclivity for eating immature shrimp, so it’s best to keep adult shrimp in the tank.


Galaxy Rasbora fish are omnivores that eat small animals. They consume spineless species, zooplankton, worms, and tiny invertebrates in the wild. The mouths of these fish are tiny, and they feature pharyngeal teeth. These fish can eat dry food that is tiny enough to fit their mouth in the tank, such as premium grade flakes. Because these fish like to stay at the bottom of the tank and rarely swim to the surface, it’s best to feed them food that sinks rather than floats.

You may also feed them small frozen foods like daphnia, moina, brine shrimp, small tubifex, small white worms, and dry krill to aid improve fin colour and spawning.

Make sure to offer them a variety of foods rather than the same thing over and over, since this will make them more vivid. Also, keep an eye on the fish to see if any of them are being crowded for food. This will help them survive longer; on one side, you may feed the more dominating fishes, while on the other, you can feed the shy ones.


The fish were successfully bred for the first time by aquarists Pete Liptrot and Paul Dixon of the Bolton Museum Aquarium in the United Kingdom. Every day, whether in their natural habitat or in the tank, these fish reproduce.

Breeding is not difficult since the sex of the fishes is so easily distinguished. At the age of three months, Celestial Pearl Danio begins to reproduce. Simply seek for fish with a round belly that are larger in size. Female fish will also be noticeably darker in color. If the female fishes are in good shape, they will spawn more frequently in a well-kept aquarium.

Introduce a single pair or two males and multiple females to a single tank. The greater the number of males, however, the greater the chance of egg predation and increased rivalry among them. Males hover over a clump of plants with their bodies at a head-down angle at the bottom during a spawning session, while females swim over to them and begin the spawning. The couples do not create any kind of bond and might have several mates. Because they can consume the available eggs, it’s better to have only one couple in a tank for breeding. Remove them once spawning is over.

In a single spawning session, well-conditioned fish may deposit up to 30 eggs, and they lay eggs in areas with low to medium water flow. Feeding them live food, as previously mentioned, will encourage early spawning. If you want the females to lay more eggs, make sure the tank is kept at the proper pH and temperature. Fine wool mops or another fine-leaved plant should be present in the tank.

Because the males are voracious egg eaters, they will hunt out any eggs that are strewn about; if you find any, place them in a breeding tank. To isolate the eggs from the aggressive males, use a spawning grate, such as a plastic needlepoint canvas. These eggs will require 72 hours to incubate before moving on to the larval stage, where they will begin to swim.

The freshly born fry is black in color and may be found near the tank’s bottom. They don’t move much at first and only start swimming after a few days. They lose their black hue with time and take on a faded silver tone.

Feed the fish micro meals, such as paramecia, in the breeding tank at first, and then live food, such as newly born brine shrimp, once the fry are old enough to consume them, after approximately a week. This species grows quickly; in approximately 10 weeks, they develop adult colour and size, and by the 14th week, they have reached adult size. At 11-12 weeks of age, you can begin breeding the following generation.


It’s critical to keep a watch on males courting females right from the start, as they spend the majority of their time doing so and competing with other guys for possible mates.

On the sides of the fish, you can see any ripped fins or bite marks. This is not only harmful to the fish, but it also causes fin rot. Fin rot may also be caused by poor water quality in the aquarium, and there are several strategies to avoid it. Maintain the right pH and temperature of the water to keep the tank in the best possible condition for the fish.

Fin rot may be treated or avoided by changing the water often and using antibacterial treatments.

Aquarium requirements

These fish live in tiny ponds that are alkaline and have a temperature of above 24 degrees Celsius in their native habitat. However, because the water is shallow, the temperature fluctuates, and the fish have been used to this.

The Celestial Pearl Danio is a very cautious fish that may quickly adjust to a new environment in an aquarium setting. To provide them with a comfortable living environment, fill the tank with a variety of plants and a dark substrate. The lack of vegetation will make the fish agitated and uncomfortable, causing them to hide all of the time. These fish will act naturally in the presence of a big number of plants. Males have plenty of room to wander about and avoid fighting in a huge tank with up to 10 gallons of water. This species should not be kept alongside other fish or shrimp for reproductive reasons. You can, however, introduce other suitable species to these fishes for exhibition purposes.

The following are some fundamental aquarium requirements for keeping these fish:

  • Water should be medium-hard with a pH of 7 or slightly higher.
  • The water must be filtered on a regular basis to ensure that it is clean.
  • The temperature in the tank should be between 22 and 24 degrees Celsius; else, the fish may perish.
  • Because the fish come from sunlight ponds, strong illumination is required. As long as the LED light does not grow too bright, you may utilize it.
  • You may also add some floating plants since if the aquarium is completely covered with plants, it will be difficult to view the fish.
  • Large aggressive fish should not be kept with this species; instead, introduce adult shrimps to the aquarium. The fish gets along well with other fish of similar size.
  • Only males and females of the same species are allowed in the tank when mating.
  • Slow to medium-moving water is ideal for these fish.
  • To provide them a natural-looking habitat, you should include a lot of pebbles, almond leaf litter, and driftwood.
  • Maintain a shallow tank to match the characteristics of their natural environment.

This is a low-maintenance fish that may be kept in tiny aquariums. It does, however, need a steady environment and some upkeep. Their vibrant colors and ability to clump together provide vitality to any aquarium. It is a nice breed of fish for novices to learn about because it is a less difficult breed.