Celestial Pearl Danio With Betta

Celestial Pearl Danio With Betta

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Celestial Pearl danios are beautiful, peaceful nano fishes that make a very attractive addition to a community tank. But can these fish get along with betta fish?

Despite their reputation for being aggressive, Siamese Fighting fish or bettas are generally happier with some peaceful tank mates. A lonely betta can easily get stressed, and these fish often enjoy a little company.

So, is the Celestial Pearl Danio a good fit for your betta, and can the two be forever finned friends? 

Keep reading to find out!

What Are Celestial Pearl Danios?

Celestial Pearl Danio

Celestial Pearl danios (Danio margaritatus) are small freshwater fish that live in heavily vegetated ponds in South East Asia, specifically Hopong. These fish were discovered in 2006, quickly gaining popularity in the hobby and now appearing in many home aquariums.

These fish are brightly-colored active little creatures that thrive in densely planted tanks as part of a peaceful community setup. These fish are quite shy and can be skittish, so they don’t appreciate the company of boisterous or semi-aggressive species.

Celestial Pearl danios are also often called Galaxy rasboras and Fireworks rasboras.

The species was initially called Celestichthys margaritatus, and the genus Celestichthys was created specifically for them. But a few years later, the species was reclassified as a danio, and the fish was renamed the Danio margaritatus.

Endangered Species

Shortly after the fish was first discovered, its numbers in the wild reportedly crashed. At the time, breeding the Galaxy rasbora in captivity was difficult, so most of the specimens that found their way into the trade were taken from the wild. That caused even further depletion of the wild population.

Since these fish live in small pools, populations were being wiped out in some places by overfishing. Fortunately, these fish are prolific breeders, spawning almost constantly. So, fished-out ponds were discovered completely restocked within just a few months.

To protect the fishes’ wild numbers, the Myanmar government banned the exportation of Celestial Pearl danios in 2007. However, according to the IUCN Red List of Endangered Species, the species is listed as “decreasing.”

Celestial Pearl Danio vs. Betta

So, how do Celestial Pearl danios compare with bettas?

Origins and Natural Habitat

Bettas are found in slow-moving waters, such as ponds, marshes, and rice paddies across much of Asia.

Galaxy rasboras are small cyprinids from the southeast of Asia, specifically from a tiny area near Hopong in Burma. These fish also inhabit shallow waters where the current is slow, and both species live in densely planted, dimly lit habitats.


Celestial Pearl danios are small fish that grow to measure between 1 and 1.5 inches long.

Males are bright blue and bronze-green, adorned with tiny pearly spots. Females are dull blue-green with a yellowish-white belly. Both sexes have transparent gill covers that show off the gills’ bright scarlet color. In the breeding season, male fish develop a red underbelly, and the pearls become even more apparent.

In comparison, bettas are larger, growing to measure up to 3 inches in length. Bettas also boast brilliant colors and come in many different forms, as well.

Life Expectancy

Celestial Pearl danios can live for up to five years, the same average lifespan as bettas.

Activity Levels and Temperament

Bettas are generally peaceful characters, spending parts of their days patrolling their territory and resting between by taking naps on flat leaves and betta hammocks. 

But, these fish are also known to be territorial, and they can be very aggressive. For that reason, you can’t keep two male bettas together. Bettas are also called Siamese Fighting fish, and for very good reason! That said, some betta fish can get lonely and stressed, and so they benefit from the company of small peaceful tank mates, including shrimp or snails.

Celestial Pearl danios are fast swimmers and are somewhat nervous and skittish, taking cover and remaining hidden when alarmed. These fish swim in all areas of the water column but gravitate mainly to the mid-water and bottom areas of the aquarium. Unlike many small fish species, these danios are not natural schooling fish, although they will gather in loose groups to feed.

Celestial Pearl danios can live in groups, but males can be very aggressive toward each other, so it’s best to keep one or two males and several females.

Diet And Feeding

Although bettas are primarily meat-eaters, they do eat some plant matter and algae. Galaxy rasboras are also omnivores, enjoying a natural diet of zooplankton, insect larvae, small worms, and algae. 

So, you can feed both fish the same diet of mini slow-sinking pellets, frozen bloodworms, daphnia, brine shrimp, etc. Feed your fish twice a day, only offering what they will take in a few minutes. However, we recommend that you include one fasting day in your betta’s feeding regimen. That allows the betta’s digestive system to process any food that’s still passing through it before adding more, preventing common problems, including bloat, constipation, and swim bladder disorders. 

Tank Requirements

Tank Size

Both Celestial Pearl danios and betta fish are regarded as nano fish. That means you can keep both of these fish in a small 5-gallon tank, although a 10-gallon aquarium is better if you’re planning on keeping a community of fish.

Ideally, you want a long, shallow, and wide tank for bettas and Celestial Pearl danios. Bettas aren’t powerful swimmers, and they need to be able to reach the water surface easily to breathe through their labyrinth organ and feed. The danios need a decent amount of swimming space, but they also appreciate hiding among plant stems when they need to.

Both bettas and danios can jump, so you need an aquarium with a tightly fitting lid or a cover slide.


Betta fish and Celestial Pearl danios live in similar environments with lots of dense vegetation and many places to hide. Caves, rocky overhangs, and well-soaked driftwood all make good decorative items for both these fish species.

Use a wide array of plants, including carpet and low-growing species, to provide shelter at the bottom of the tank for the danios to use as shelter, and include taller species that provide a safe haven in the mid to upper areas of the water column. 



Both bettas and Celestial Pearl danios inhabit very slow-moving waters where the current is very slow or non-existent. 

So, in the aquarium, you need a filtration system that doesn’t create much current, or the fish will become stressed, potentially leading to health problems. For that reason, we recommend a sponge filter for betta fish and these danios. 

Water Parameters

If your fish are to thrive and be happy, the water parameters in their home must be suitable.

Water Temperature

Both these fish species are tropical, warm water creatures. Celestial Pearl danios require a water temperature of between 71° to 78°F while betta fish like a water temperature between 75° and 81°F. So, both fish can tolerate the same water temperatures, although the danios prefer slightly cooler conditions.

In a betta tank, the water temperature should be as close as possible to the ambient room temperature so that the sensitive labyrinth organ isn’t damaged.

Water Hardness and pH

Celestial Pearl danios prefer water with a pH range of between 6.5 and 7.5 and a soft to medium water hardness of between 2 to 10 dKH.,

In comparison, betta fish need a pH between 6.5 to 7.5 and a water hardness of between 3 and 5 dKH. So, the two species enjoy very similar water conditions.


Both Celestial Pearl danios and bettas live in dimly lit waters in their natural habitat. In the home tank, you can recreate that environment by including floating plants and using a lighting unit that has an adjustable setting.

Tank Maintenance

Even though bettas live in stagnant waters in their natural environment, you must keep your pet’s tank clean and well-maintained if he’s to thrive. Similarly, your danios will suffer if the water is dirty.

Well-oxygenated water is also essential for both species. The amount of dissolved oxygen in the water is not enough to support bettas, which is why they breathe atmospheric air at the water surface through their labyrinth organ.

For both species, stable water parameters are essential. Any rapid fluctuations in temperature can severely stress your fish, causing temperature shock and potential fish deaths. 

Partial Water Changes

Every week, you need to carry out partial water changes, replacing around 20% of the old tank water with fresh. That ensures nitrate levels remain around or below 20ppm, which is a healthy level for your tank.

Remove Organic Waste

When performing your partial water changes, use an aquarium vacuum cleaner to remove any organic matter from the aquarium substrate. Fish waste, uneaten food, and plant debris fall into the substrate where they slowly rot, releasing toxins into the water that could potentially kill your fish.

There are hotspots to watch out for underneath filter boxes, around plant bases, and in the tank corners. As you work, push the vacuum deep down into the substrate to eliminate any hypoxic dead zones that might form.

Maintain Filters

Your tank water won’t stay clean and healthy for your fish if you don’t maintain the filtration system. So, every month, you need to remove the filter media and rinse it in tank water to remove solid waste that would otherwise clog the media and obstruct the water flow.

Filter media and cartridges will need replacement every so often, as per the manufacturer’s recommendations.

Health and Disease 

Bettas and Celestial Pearl danios are reasonably robust species, but they can be susceptible to common fish diseases if the water quality in the tank is poor. 

The best way to keep your fish healthy and safe from the likes of Ich and bacterial diseases is to keep the tank clean, don’t overcrowd your tank, only use high-quality fish food, and avoid overfeeding your fish.

However, some common health problems might affect your fish, including the following:

White Spot Disease (Ich)

White Spot Disease, Ich, and Ick are all the same disease but by different common names. 

Ich is just about the most common freshwater fish parasite that attacks aquarium fish. The disease is caused by Ichthyophthirius multifiliis, an aquatic parasite that occurs in most home tanks. Healthy fish living in good conditions are not generally affected by Ich, but the parasite strikes when fish are weak.

When the free-swimming form of the parasite attaches itself to the fish, the irritated fish rubs or flashes against solid objects in the aquarium, including the substrate. A few days later, the parasite becomes visible as a scattering of minute white dots like grains of salt across the body, gills, and fins.

White Spot disease is easily treatable by increasing the water temperature to 82 degrees Fahrenheit and using an Ich medication to treat the whole tank.

Bacterial Infections

When fish are injured or weakened by disease, bacterial infections can develop. Some species of bacteria attack the fish’s gills, others target the internal organs, while some affect the fins.

Common symptoms of bacterial infections include:

  • General poor health and failure to thrive
  • Lethargy
  • Lack of or loss of appetite
  • Red sores or ulcers on the skin
  • Torn, ragged fins

You can treat many bacterial diseases relatively easily if you spot them quickly. Generally, antibacterial medication and water changes are effective.

Digestive Problems

Both bettas and Celestial Pearl danios can be susceptible to digestive disorders, such as bloat, constipation, and swim bladder problems.

Those issues are generally caused by overfeeding or feeding the fish with poor quality fish food. You can usually prevent those problems by only buying high-quality food that doesn’t contain grains and other fillers. Also, include frozen meaty foods in the fishes’ diet to provide fiber and keep the food moving through the fishes’ digestive tract. 

You can also include one fast day per week when you don’t feed your fish at all, allowing any residual food in the fish’s gut to move through and be expelled before adding more to the load.


Both betta fish and Celestial Pearl danios are egg layers. However, bettas are much easier to breed than danios.

Celestial Pearl Danio

Unfortunately, it’s difficult to breed Celestial Pearl danios in the home tank, primarily because the fry are extremely delicate and sensitive to water conditions, and they often don’t make it.

Also, if the female lays her eggs while you’re not around, the chances are that the parent fish will eat the eggs before they hatch.

Betta Fish

Betta Fish

In contrast, bettas are pretty easy to breed in the home tank. 

Betta fish are bubble nesters, with the male typically creating nests underneath flat plant leaves, in tank corners, or under floating plants. 

After an elaborate spawning ritual, the female lays her eggs under the nest. The male fish picks up the eggs in his mouth and carefully transfers them to the nest. He will then guard the eggs until they hatch. At this point, you need to remove the female, as the male might attack her.

The fry become free-swimming after a few days. Now, you’ll need to remove the male, as he might mistake the fry for food and eat them.


You can find Celestial Pearl danios and bettas in most local fish stores and online. 

Bettas cost around $15, although you will pay more for unusual colors and extravagant finnage. Celestial Pearl danios general retail for about a few dollars per fish.

Can Celestial Pearl Danios And Bettas Live Together?

As you can see in this video, Celestial Pearl danios and betta fish can be pretty good tank mates.

Both species share comparable water conditions and temperatures, and both need a well-planted tank with lots of shelter. You can keep the two species in a relatively small tank, and both enjoy a very similar diet.

However, bettas are highly territorial, aggressive fish, whereas the danios are skittish and easily startled. So, the two might not mix if the betta is super-feisty. However, you can mitigate that potential issue by keeping a larger group of danios.

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