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Contents
Overview
The celestial pearl danio, also sold as the galaxy rasbora, was discovered in 2006 in small, heavily vegetated ponds and marshes on the Shan Plateau of Myanmar. It became an instant hit: a dark blue body dotted with gold spots like a starry sky and fins banded in red and black, brightest on the males.
At only about 1 inch (2.5 cm), it is a favorite for planted nano tanks and shrimp tanks. Nearly all fish sold today are captive-bred, which matters, because heavy collection in the early years hit wild populations hard. It isn't difficult, but it is shy, and it only truly shines in calm, densely planted aquariums.
Care and tank setup
A school of ten or more does well in a 10-gallon (40-liter) tank or larger, 18 to 24 inches long and heavily planted. In a bare tank they hide and lose their color.
- Plants: dense stands of fine-leaved stem plants, mosses and floaters to soften the light.
- Water: clean and stable, near-neutral pH and moderate temperatures; they don't handle prolonged heat well.
- Flow: gentle. A sponge filter is ideal.
- Tank mates: dwarf shrimp, snails, otocinclus, pygmy corydoras and other nano danios or tiny rasboras.
Males spar often, flaring and circling each other, but rarely cause damage when there is cover. A classic mistake is housing them with large or boisterous fish that outcompete them at feeding time and keep them hiding. Aim for more females than males.
Feeding
Their mouths are tiny. Offer micro pellets, crushed flakes and, above all, small live or frozen foods: baby brine shrimp, daphnia, cyclops or microworms. New arrivals sometimes accept only live food at first. Several small feedings a day work best.
Breeding
They spawn readily in mature tanks: males court the females and the pair scatters eggs into moss or fine roots. The parents eat them, so if you want fry, move the moss to a separate container filled with tank water. Eggs hatch in about three days; the fry need infusoria, then baby brine shrimp.
Compatible tank mates
Species from our database that share water parameters, size and temperament with the Celestial pearl danio. Calculated from the data in each profile.
Bristlenose pleco Ancistrus sp. 26 gal (100 L) · 72–81 °F (22–27 °C) 
Bronze cory Corydoras aeneus 21 gal (80 L) · 72–81 °F (22–27 °C) 
Guppy Poecilia reticulata 14 gal (54 L) · 72–82 °F (22–28 °C) 
Nerite snail Neritina natalensis 5 gal (20 L) · 72–82 °F (22–28 °C) 
Horned nerite snail Clithon corona 5 gal (20 L) · 72–82 °F (22–28 °C) 
Panda cory Corydoras panda 16 gal (60 L) · 68–77 °F (20–25 °C) 
Zebra danio Danio rerio 16 gal (60 L) · 64–77 °F (18–25 °C) 
Amano shrimp Caridina multidentata 11 gal (40 L) · 64–82 °F (18–28 °C) 
Cherry shrimp Neocaridina davidi 5 gal (20 L) · 64–81 °F (18–27 °C) 
Otocinclus catfish Otocinclus vestitus 16 gal (60 L) · 70–79 °F (21–26 °C) 
Platy Xiphophorus maculatus 16 gal (60 L) · 68–79 °F (20–26 °C) 
Harlequin rasbora Trigonostigma heteromorpha 16 gal (60 L) · 72–81 °F (22–27 °C) Check the compatibility of your whole tank →
What not to keep it with
Popular species you shouldn’t house with the Celestial pearl danio, and why.
- Common goldfish: one may eat the other due to size
- Discus: incompatible temperatures, one may eat the other due to size
- Angelfish: incompatible temperatures, one may eat the other due to size
- Yellow lab cichlid: incompatible temperatures, incompatible pH, one may eat the other due to size
- Clown loach: incompatible temperatures, one may eat the other due to size
- Oranda goldfish: one may eat the other due to size
- Oscar: one may eat the other due to size, incompatible temperaments
- Ram cichlid: incompatible temperatures
Recommended equipment
What you need to keep the Celestial pearl danio healthy, checked against Amazon stock.
Frequently asked questions
How many liters does a Celestial pearl danio need?
At least about 40 liters for a group of at least 10 fish. More space always helps keep the water stable.
What water temperature does the Celestial pearl danio need?
Between 20 and 25 °C, with a pH of 6.5 to 7.5.
What fish can live with the Celestial pearl danio?
Based on water, size and temperament, it fits with species such as Bristlenose pleco, Bronze cory, Guppy, Nerite snail and Horned nerite snail. Use our compatibility calculator to check your whole tank.
Can the Celestial pearl danio be kept with shrimp?
Yes: it usually won’t eat adult shrimp, though some shrimplets may get picked off. A tank with plenty of moss gives the babies cover.
