Celestial pearl danio care (galaxy rasbora)

Celestial pearl danios, or CPDs, are tiny fish with dark blue bodies, gold spots and bright orange fins. They look like a starry sky in a planted tank. They're hardy, but shy and small-mouthed, so they need the right tank and food to show their colors.

CPDs are one of the fish I keep in my own planted tanks.

Celestial pearl danio facts

• Other names: galaxy rasbora, Danio margaritatus
• Size: about 1 inch
• Tank: 10 gallons for a small group, 20 gallons long or more for a group of 10 or more
• Temperature: 72–76°F. They like it a little cooler than most tropical fish.
• Water: pH about 6.5 to 7.5, soft to medium hardness
• Group: 6 at the very least, 10 or more is better
• Lifespan: about 3 to 5 years

Setting up a CPD tank

• Plants, and lots of them. CPDs hide in open tanks and come out in planted ones. Java moss, stem plants and floating plants that soften the light all help. See easy aquarium plants.
• Dark sand or soil brings out their colors.
• A gentle filter. A sponge filter or a small hang-on-back with the flow turned down.
• A lid. Small danios can jump when startled.
• A cycled tank. Add them only after the tank is fully cycled. See how to cycle a fish tank.

Males and females

Males have deeper blue-black bodies and bright red-orange fins with black stripes. Females are more olive with paler orange fins and a rounder belly. Males spar with each other all day, flaring their fins. It looks dramatic but rarely causes harm in a big enough group with plants to break up sight lines.

Feeding

Their mouths are tiny. Feed small foods like micro pellets or crushed flakes once or twice a day, with frozen or live baby brine shrimp, daphnia or cyclops a few times a week. New CPDs often ignore dry food at first, so frozen food helps them settle in. See how often to feed fish.

Good tankmates

Avoid anything big enough to fit a CPD in its mouth, like angelfish, and fast, pushy eaters like tiger barbs. Bettas prefer warmer water and may chase them. Check a mix with the fish compatibility checker.

Do they breed in a community tank?

CPDs scatter eggs in moss and plants, and in a well-planted tank you may spot a few fry hiding near the surface. The adults eat most eggs, so moving a clump of java moss to a small, bare tank with a sponge filter is the usual way to raise more. For the basics of raising fry, see breeding aquarium fish.

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