Should I buy it?
Celestial Pearl Danio
Danio margaritatus
Also known as: galaxy rasbora, cpd
A 2.5 cm nano gem with spotted pattern and red fins. Peaceful in a careful community. Stress-intolerant in boisterous or overstocked setups.
Celestial Pearl Danio tank mates · 30L tank size hub
peaceful · intermediate care
Sources & confidencehigh · partially verified · beginner: caution
Checked against several solid care sources that mostly agree. Numbers here are a careful starting point. Your tap water, tank size, and habits decide the rest. How we evaluate.
Best for: Planted nano tanks 30–60L with a school of eight or more CPDs and small peaceful companions or shrimp.
Avoid if: You keep active larger fish that outcompete for food or stress the 2.5 cm fish with constant motion.
Common mistakeHousing CPDs with active danios or barbs is how keepers invent slow starvation in a ‘peaceful’ nano. Competition at feeding stresses the smaller fish until they stop eating. Keep calm nano neighbours and an honest school of eight or more — not zebra danios for ‘energy.’
Top things that go wrong
- Group welfare — not a solo display fish. Plan at least **8** together for normal behaviour; smaller groups often mean stress, colour loss, or nipping depending on species.
- Shrimp & snails. Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
What most shops don't tell you
- 1.Myth: celestial pearl danios thrive mixed with any active danio or barb community for interest. Reality: they lose feeding contests and fade — keep eight or more with calm nano species only, not a high-speed midwater free-for-all that starves the pearls.
- 2.Buying three or four to start. Celestial Pearl Danio settles in a group of 8 or more. An understocked school sulks at the back of the tank and loses colour within a fortnight.
- 3.Very small. Avoid large or predatory tank mates. Best in planted nano tanks with gentle filtration. Keep eight or more from one tank.
About this species
Celestial pearl danios are 2.5 cm Myanmar cyprinids with pearl spots on a blue body and orange-red fins. A nano schooler that needs eight or more of its own kind to settle.
- Chili Rasbora20L min · same group, comparable tank size
- White Cloud Mountain Minnow40L min · same group, comparable tank size
- Cherry Barb60L min · same group, similar adult size
- Dwarf pencilfish60L min · same group, similar adult size
- Harlequin Rasbora60L min · same group, similar adult size
- Lambchop / Espei rasbora60L min · same group, similar adult size
- Zebra Danio60L min · same group, similar adult size
- Golden / Beckford's pencilfish80L min · same group, similar adult size
- Cardinal Tetraalso intermediate peaceful, similar tank size
- Chili Rasboraalso intermediate peaceful, similar tank size
- Clown Killifishalso intermediate peaceful, similar tank size
- Dwarf pencilfishalso intermediate peaceful, similar tank size
- Golden dwarf cichlid (Nannacara)also intermediate peaceful, similar tank size
- Green neon tetraalso intermediate peaceful, similar tank size
- Chili Rasbora tank matesnames this fish as a conditional pairing — read the pair page conditions
- Pygmy Corydoras tank mateslists this fish as a safe and recommended mate
- Sparkling Gourami tank matesnames this fish as a conditional pairing — read the pair page conditions
Plan grid
Key limits are above. Here: pH band, swim level, bioload, and activity.
Swim zones
Care snapshot
Quick compare before you buy. Not a score of how “good” the fish is.
- Beginner ease38
- Peacefulness90
- Community fit76
- Small-tank fit100
- Hardiness54
- Energy24
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Example setups
Starting points only. Run the pair checker for every fish you add.
Rough 90L+ layout: one calm centrepiece, 8–12 small tetras/rasboras, 6–8 corydoras-type bottom fish — verify every name in the pair checker before buying.
Safer directions include: Otocinclus, Pygmy Corydoras.
Prioritise 8+ of Celestial Pearl Danio in 30L+ with filtration sized for messy feeding — add only mates that already pass pair checks with this species.
Compatibility
Tank mates for Celestial Pearl Danio
Usually safer (engine GOOD): Otocinclus, Pygmy Corydoras. Conditional (CAUTION — read the pair page before buying): Betta, Chili Rasbora, Tiger Barb. Avoid (RISKY): Angelfish, Oscar. Every name links to a live pair check — the lists are a shortlist, not a stocking plan.
Usually safer
Open a pair page with this fish as the starting point.
Needs planning
Read the blocking rule on each pair page before experimenting.
Usually avoid
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Celestial Pearl Danio + Otocinclus
- Try Otocinclus — open the pair check.
- Try Pygmy Corydoras — open the pair check.
Behaviour and temperament
Celestial pearl danios are peaceful nano schoolers that stay calmer in groups of eight or more. They do not bully robust neighbours. Stress shows as hiding and refusal to feed when larger active fish monopolise every food pinch at the surface.
What sets them off
- Sudden crowding
- Poor water quality
Fin nipping: Not a habitual fin-nipper; stressed or crowded individuals can still test fins.
Predation: Not a predator toward similarly sized community fish; fry and dwarf shrimp are still fair game for most species.
Territory: Not strongly territorial, but still needs room so its working space does not overlap the next fish.
Planted tanks: excellent — easy plant ideas
In the glass: typical and warning signs
- Eight or more hold midwater among plants with males flashing pearl flanks.
- Mild in-school sparkle is normal display in a calm nano.
- Fish that stop rising at food after barbs arrive mean competition failed.
- A scattered handful usually needs more of their own kind first.
- Low listed risk as aggressors.
- Males may spar lightly inside a proper school without shredding neighbours.
- Remove active competitors before dosing mystery meds for ‘not eating.’
- Increase school size before adding another nano species to fix shyness.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Water, food, and grouping
Hardness
soft
Diet
omnivore
Celestial pearl danios are tiny midwater omnivores with small mouths. Micro-pellets, crushed foods, and frozen baby brine or daphnia get taken; wafers on the sand rot unnoticed. Feed small pinches a school of eight or more can finish among plants, and never make them compete with frantic danios or barbs for every crumb.
Shrimp & snails
Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
Schooling species — buy 8+ together. Smaller groups stress and lose colour.
- Hold 22 to 26 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 6.5 to 7.5 and a hardness you can re-test in two weeks. A one-time strip in the shop car park is not a water test.
- Schooling species. Buy 8 or more from the same tank on the same day before adding any centrepiece fish.
- Tank volume meets or exceeds 30L published minimum for adults.
- You can stock at least 8 individuals (group welfare).
- Heater can hold 22–26°C without cooking cooler-water tank mates.
Explore and stocking hubs
Tank-mates hub, matching guides, category peers, and litre stocking lists around this species’ minimum tank.
Plan with tools
Check mates as pairs first, then add this fish in the tank builder for the full stocking.
Filtration & heating
A 30L minimum tank needs a filter rated for at least 120L/hr turnover and a heater to hold 22–26°C reliably.
Plant suggestions
Celestial Pearl Danio does well in planted tanks. Plants compatible with 22–26°C and pH 6.5–7.5:
Research: partially verified · Confidence: high · 3 linked source(s). We do not invent citations.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- Seriously Fish. Danio margaritatus
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Danio margaritatus
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Danio margaritatus
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
Evidence notes
- The Seriously Fish profile for the binomial in this record was successfully reached as the primary aquarium reference.
- FishBase contributes natural-range size and habitat context. Translate those numbers through your heater, your water report, and your tank footprint before stocking.
- Wikipedia is only cited if the article URL returned OK. Use it for orientation, not as the only care sheet for an import.
- All compatibility text reflects typical hobby experience and the Fishori model. Individual fish, shop stress, and the order tank mates are added in can still defy a single-paragraph label.
Featured compatibility checks
Curated pair pages for Celestial Pearl Danio. Each opens a full verdict — not just a list label.
Common questions about Celestial Pearl Danio
- How big do Celestial Pearl Danio get?
- Celestial Pearl Danio adults reach about 2.5 cm. Shop fish look smaller; stock for the adult length.
- What size tank does Celestial Pearl Danio need?
- 30L is the planning floor for adult swimming space and bioload. A 37L+ tank is the more comfortable long-term footprint. Length and depth matter as much as raw litres for active or territorial fish.
- Are Celestial Pearl Danio aggressive?
- Celestial pearl danios are peaceful nano schoolers that stay calmer in groups of eight or more. They do not bully robust neighbours. Stress shows as hiding and refusal to feed when larger active fish monopolise every food pinch at the surface.
- Do Celestial Pearl Danio need to be kept in a group?
- Schooling species — buy 8+ together. Smaller groups stress and lose colour.
- What is the most common mistake with Celestial Pearl Danio?
- Housing CPDs with active danios or barbs is how keepers invent slow starvation in a ‘peaceful’ nano. Competition at feeding stresses the smaller fish until they stop eating. Keep calm nano neighbours and an honest school of eight or more — not zebra danios for ‘energy.’
- What fish can live with Celestial Pearl Danio?
- The Celestial Pearl Danio profile lists Otocinclus, Pygmy Corydoras among its safer pairings (engine-checked GOOD). Betta, Chili Rasbora, Tiger Barb are conditional (CAUTION): workable only with the specific conditions on each pair page. Avoid Angelfish, Oscar (RISKY). Run the pair checker for your exact water and tank size before stocking.