Celestial Pearl Danio Care: Tank Setup, Feeding, Breeding

Are danios nano fish? Small tanks aren’t great for zebra danios who are hyperactive swimmers that need space to dart around.

But celestial pearl danios, also known as galaxy rasbora, are excellent nano fish. Colorful, peaceful, small, and not the most avid swimmers, a shoal of these beautiful little fish will brighten up any tank. They like to have many hiding spaces, slightly colder water, and a good amount of food.

Celestial pearl danios aren’t the best centerpiece fish out there, as they can be a bit shy, but with the right setup, diet, and tankmates they will be spending plenty of time out in the open.

Let’s see what galaxy rasboras need to thrive.

Celestial Peral Danio Water Parameters

Celestial pearl danios come from Burma, but they don’t like their water overly warm because their natural habitat is slightly elevated. While fully compatible with a tropical tank setup, their preferred temperature is up to 24°C-25°C or 75°F-76°F. This is on the lower end of the spectrum for most tropical fish.

Here are the basic water parameters for celestial pearl danio:

• Temperature — 21°C-26°C or 70°F-78°F
• pH — 6.5-7.8 is the recommended range, but celestial pearl danio can tolerate ph in the 8.0-8.3 pH, too
• Hardness — 1-6 dGH

Lower water temperatures have a few benefits. They slow down the decomposition of uneaten food or decaying plant matter, impeding the ammonia release in the water column. Rabbit snails and mystery snails also benefit from these lower temperatures, while many corydoras species prefer them, too

However, ich is one of the diseases that also likes colder waters.

CPDs are fairly easy to stress out if the water parameters fluctuate and the water column is polluted. Recognizing early signs of stress is essential, but maintaining the water parameters stable is the way to go in the long run.

Buffers like higher KH and a reliable maintenance routine help a lot in that regard.

Tank Size and Setup for Celestial Danios

Celestial pearl danios are excellent nano fish. Besides their small size, they aren’t as frantic swimmers as other danio species like the regular pearl danio or zebra danio.

Galaxy danios like calm water, so a sponge filter or hang-on-the-back are great options, whereas a powerhead can tire them out.

They swim in the mid-lower strata of the water column and need spots with calm water to chill. If the fish are few in number (and sometimes even if they are many), they are likely to spend most of their time hiding among vegetation.

Providing enough cover in the form of stern plans like Ludwigia repens and Hygrophila polysperma or Vallisneria is essential for keeping CPDs stress-free and comfortable.

• Tank size — Even a 5-gallon or 20-liter tank would do, but since celestial pearl danios are social fish that feel secure in numbers, at least a 10-gallon or 40-liter aquarium would be better.
• Tank shape — Any will do, galaxy rasboras don’t swim like crazy
• Substrate — Whether sand or gravel, it doesn’t matter much, but opt for darker shades. Darker substrates make their colors stand out and give them a greater sense of security, lowering stress.
• Decorations — Celestial pearl danios like to hide among dense vegetation. Rocks will also do, but plants are definitely a better choice for these slightly skittish little fish.
• Light — Medium to strong light will do. Basically, plan lighting for a planted tank, as you’ll have to keep a good amount of greenery for these beautiful nano fish.

Indeed, water parameters aren’t as crucial as their stability, the water cleanliness, and the amount of plants for hiding. In larger tanks, you can keep more galaxy danios and observe increasingly complex social dynamics.

CPD: Origin Story

Celestial pearl danio is a relatively new addition to the fishkeeping hobby. The species were discovered in 2006 and were initially classified as rasboras, hence their popular common name galaxy rasbora.

Upon closer inspection, the new species were identified as a member of the Danio family and re-classified accordingly.

• Name  — Danio margaritatus
• Common names  — Celestial pearl danio, galaxy rasbora, galaxy danio
• Country of origin  — Burma (Myanmar), the Salween river

The way this species was discovered is a truly fascinating story that sheds light on the way new animal species are analyzed, classified, and popularized, within the hobby and beyond.

Celestial Pearl Danio Appearance

CPDs are beautiful but hard to capture in a still photo (especially by a mediocre photographer like yours truly), but I gave it a fair few shots.

All the same, let’s see if words can do justice to this little aquarium trout.

• Lifespan  — 3-5 years
• Size  — 1.5cm-2.5cm or 0.75in-1in

Celestial pearl danios got their initial name — galaxy rasbora — thanks to the dark, deep blue or black sides of their bodies, which are dotted with numerous white spots. A bit like stars in the night sky.

Their fins are brownish-red, with dark stripes running along. Overall, it is a stunning-looking fish.

Their shape resembles a trout and, honestly, the dotted patterns also look a bit trouty.

Sexing and Breeding Celestial Pearl Danio

Breeding celestial pearl danios is relatively easy.

Feed them a high-protein diet, keep the water clean and cool, and they should start their mating rituals which involve a lot of dancing and some competition among the males to assert dominance.

Separating male from female celestial danios isn’t that difficult. Males are slightly slimmer and longer, with brighter colors. Females are plumper, with rounded bellies and duller colors.

Just like danio rerio breeding, their celestial cousins are likely to eat their eggs. Spawning mops or moss helps the eggs to hang, but for increased safety is better to put a net or plastic mesh. This way, the eggs will fall through the mesh, out of reach from their hungry parents.

The fry eat infusoria and egg yolk. Baby brine shrimp can enter their diet 7-10 days after they spawn.

Celestial Pearl Danio Behavior

CPDs are very docile fish. They like to swim among plants and feel safer in a shoal of 5-6 (or more) fish.

They aren’t aggressive, even though, like most danios, can be fin-nippers.

The only time celestial danios show aggression is toward their own species. Males will stack against each other to determine their hierarchy.

That’s why it is best to keep celestial pearl danios in tanks of at least 40 liters or 10 gallons. This way, the subdued males will have room to hide. Again, provide plenty of leavy cover so that all your galaxy danios feel safe.

CPD Tankmates

Celestial pearl danios can coexist with pretty much any other peaceful fish species that can tolerate slightly cooler water. I’ve heard they may nip fins, which is easy to believe for any danio, but I haven’t seen it myself.

I’ve kept them with a betta fish, and didn’t have any issues.

They can live happily with:

• Barbs
• Tetras
• Gouramis
• Loaches
• Swordtails
• Catfish
• Bottom-dwellers of all kinds
• Snails
• Shrimp

Just to be perfectly safe, guppies aren’t on the list.

Celestial Pearl Danio Diet

Celestial pearl danios are omnivores. They eat wafers, flakes, live food, eggs, and more. However, feeding them is not the easiest thing in the world.

See, these danios occupy almost exclusively the mid-lower layer of the water column and rarely venture higher up. That means that any food should sink slowly enough for them to catch it, but quickly enough so that higher-swimming fish don’t eat it all.

The other difficulty is that CPDs are very small and so are their mouths. Crushing flakes or egg yolk completely is the way to go. With live or frozen food, chopping it down helps them eat it.

When Buying Celestial Pearl Danios

Celestial pearl danios are still relatively rare in the hobby. I got my last batch as an impulse buy, only because they were available. (I was planning to get harlequin rasboras when going to the shop).

When purchasing them, look for healthy individuals, with vibrant colors and good-looking fins. The CPDs can be a bit crooked, with a small angle starting at the dorsal fin. If they are too bended, it can be a sign of genetic issues, though.

Take a few minutes to observe them and make sure they are swimming without any issues. Also, make sure you have the budget and space to purchase at least five or six danios.

Celestial pearl danio are very beautiful nano fish with unique behavior, especially in larger groups. 12-15 individuals will create a very dynamic hierarchy that will enliven your tank.

They are peaceful, small, and easy to breed.

However, they are also relatively easy to stress out by dirty water and unstable water parameters, which makes them slightly more challenging fish for absolute beginners.

Hopefully, this detailed guide on the celestial pearl danio will help you to take good care of them.