Danio margaritatus
Cooler-water nano gem, keep below 25 °C for best colour and lifespan. Males display brightest with females present and dense plant cover.
Celestial Pearl Danio (Danio margaritatus) reaches 2–2.5 cm as an adult and needs a minimum tank of 40 L. Native to Hopong area, Myanmar, it lives in the mid to bottom water column with a peaceful (males spar) temperament. Aim for 20–24 °C, pH 6.5–7.5, and 2–10 dGH hardness. Lifespan is 3–5 years with good care. Keep celestial pearl danio in groups of 6+, yes (loose shoal) schoolers need numbers to display natural behaviour. Diet: micropredator, Micro pellets, baby brine shrimp, daphnia, microworms. Plant-safe: Yes. Shrimp-safe: Yes (adult shrimp).
Care at a glance
Cooler-water nano gem, keep below 25 °C for best colour and lifespan. Males display brightest with females present and dense plant cover.
By Mike ElmiraUpdated 2 min read
Part of our complete guide to aquarium fish for the planted tank.
The parameters that decide whether celestial pearl danio fits in your tank.
Mid to Bottom
Yes
Group of 6+
Cyprinidae
Micropredator
Micro pellets, baby brine shrimp, daphnia, microworms.
3–5 yrs
Medium
Tiny grass-edged ponds and rice paddies of Myanmar
Hopong area, Myanmar
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Best as species-only or with similar cool-water nano fish (white cloud mountain minnows, hillstream loaches, cherry shrimp).
Soft-water blackwater species (chili rasboras, cardinals) — they want opposite parameters. Aggressive larger fish.
Hard-won lessons from the tank.
Keep more females than males (2:1) — males spar constantly and a stressed female loses colour. A 40 L tank with 12 fish, dense plants, broken sightlines is the sweet spot.
Genus 'Danio' (from Bengali 'dhani'); species 'margaritatus' = 'pearl-like'. Originally described as Microrasbora rasbora, reclassified to Celestichthys, now Danio.
What can go wrong and how to spot it.
Failure modes, in order of how dramatic the fix is.
Generally hardy. Stress from too-warm tanks shortens lifespan dramatically.
Often kept too warm. They are a HIGHLAND fish — 20–24 °C is correct; >26 °C shortens life. Often called 'galaxy rasbora' but it's a danio.
The practical routine, read top to bottom.
30 L+. Heavily planted, hardscape with multiple sightlines (males display territory). Hard alkaline water (pH 7.0–7.5, dGH 8–15). Avoid soft-water-tank setups despite their nano size.
2–3 weeks. They ship surprisingly well.
Where it comes from, how it behaves, and the variants you'll see at retail.
Where it lived before it came home.
Cool, shallow, spring-fed grass pools at high altitude in Myanmar's Shan State (Hopong area). Water is hard and alkaline in the wild — opposite of most nano fish.
Tiny crustaceans, insect larvae, algae.
Originally listed as nearly extirpated by collection within 2 years of discovery (2006). Captive breeding now meets nearly all demand and wild populations have partially recovered.
How they pair, reproduce, and grow.
Males have intense red fins, deeper blue body, and more white spots. Females are paler with rounder bodies and clear fins.
Easy. They scatter eggs continuously in moss or spawning mops. Adults will eat eggs and fry if not separated. Cooler water (~22 °C) and pH 7.0–7.5 trigger spawning.
The named cultivars and the lookalikes worth flagging.
Wild type only. Some captive lines are paler or weaker — buy from reputable breeders.
Direct answers to the questions search engines and AI assistants surface most often about this species.
Celestial Pearl Danio (Danio margaritatus) needs a minimum tank of 40 L. They live in the mid to bottom water column and should be kept in groups of 6+, so a longer footprint matters more than depth.
Target 20–24 °C, pH 6.5–7.5, and 2–10 dGH hardness. Acclimate slowly when moving them between water sources.
Shrimp safety: Yes (adult shrimp). Plant safety: Yes.
Celestial Pearl Danio are micropredator. Micro pellets, baby brine shrimp, daphnia, microworms.
On Fin & Stem's 1–5 difficulty scale this species rates 2/5. Forgiving, beginner-friendly once the tank is cycled. Breeding difficulty: medium.
Typical lifespan in a well-maintained tank is 3–5 years.
A planted tank is a system. Pair this fish with one entry from each other pillar to plan the whole scape.
