Should I buy it?
Celestial Pearl Danio
Danio margaritatus
Also known as: galaxy rasbora, cpd, Galaxy rasbora, CPD
Fishori provides conservative planning guidance, not guarantees.
Based on multiple reputable aquarium care sources with strong agreement. Use the numbers here as planning defaults — your room, water, and routine still shape real-world outcomes.
A 2.5 cm nano gem with spotted pattern and red fins. Peaceful in a careful community. Stress-intolerant in boisterous or overstocked setups.
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.
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. Shrimp: compatible in most setups. Cherry shrimp and other dwarf species coexist with peaceful small fish, though baby shrimp are food for almost any fish that gets to them.
Common mistakeCPDs with active danios or barbs. Competition at feeding stresses the smaller fish and they slowly stop eating.
What most shops don't tell you
- 1.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.
- 2.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 mateslists this fish as a safe and recommended mate
- Pygmy Corydoras tank mateslists this fish as a safe and recommended mate
- Sparkling Gourami tank mateslists this fish as a safe and recommended mate
Plan grid
Key limits are shown above; this section adds planning detail: pH band, swim level, bioload and activity, and the radar.
Swim zones
Planning trait chart
Six indices for comparing species on paper before you spend.
- Beginner ease38
- Peacefulness90
- Community fit79
- Small-tank fit100
- Hardiness54
- Energy24
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Common setup sketches
Conservative patterns from Fishori fields — still run the pair checker for every species you add; sketches are not a stocking guarantee.
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.
Safe directions on file include: Otocinclus, Pygmy Corydoras, Chili Rasbora.
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.
Tank mate intelligence
Strictly nano-tank companions: otocinclus, pygmy corydoras, chili rasboras, sparkling gouramis, dwarf shrimp in mature, heavily planted setups. Avoid all common community staples that would either out-compete them (tiger barbs, angelfish) or stress them out of feeding (bettas, larger danios).
Pair-level compatibility with this fish as anchor.
Read the blocking rule on each pair page before experimenting.
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.
- Try Chili Rasbora — open the pair check.
Behaviour, temperament, and what to watch
Prose and lists come from the same record: read temperament first, then glass-level signals so you are not surprised after day three.
Celestial Pearl Danio is peaceful in mixed company.
Stress / aggression triggers on file
- Sudden crowding
- Poor water quality
Fin nipping: Not a habitual fin-nipper, but individuals can still test fins under stress or in a crowded tank.
Predation: Not a predator toward similarly-sized community fish. The usual community caveats about mouth size still apply for very small fry or shrimp.
Territory: Not strongly territorial, but still claims a working area in the tank. Give it room to settle without overlapping the next species' patch.
Planted tanks: excellent — easy plant ideas
In the glass: typical and warning signs
- Often calm on the glass — bursts of movement around food or tank disturbance.
- Shoaling/schooling: most colour and confidence show when the group meets **8+**.
- Clamped fins, gasping at the surface, hiding non-stop, or refusing food after the first week.
- Rapid breathing when parameters swing — fix ammonia/nitrite first, then reassess mates.
- Low listed risk — still watch new introductions.
- Separate or rehome if injuries appear, one fish is pinned, or feeding becomes a daily chase.
- If water is stable but behaviour worsens, reduce stocking or remove the highest-impact species first.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Care parameters: water, food, inverts, grouping
Chemistry and group rules sit here so you are not re-reading the same line from tank mate or temperament blocks. Swim level is in the plan grid above.
Hardness
soft
Diet
omnivore
Mixed diet: a quality flake or pellet as the staple, with frozen or live foods two or three times a week.
Shrimp & snails
Shrimp: compatible in most setups. Cherry shrimp and other dwarf species coexist with peaceful small fish, though baby shrimp are food for almost any fish that gets to them.
Shoaling species. Buy 8 or more of one species together. Smaller schools sulk, lose colour, and redirect their schooling energy at whatever else is in the tank.
Egg scatterers and schoolers still spawn in stable tanks. Have a plan for the fry, or accept that the parents and tank mates will eat them in a community setup.
- 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
Same library as the rest of Fishori: tank-mate index for this species, category peers, guides, and litre-based stocking lists where min tank on file is within the hub volume.
Plan with tools
Pair-level rules and multi-fish stocking use the same conservative engine — add this fish in the tank builder only after mates pass pair checks.
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:
Profile status: partially verified · Evidence tier: high · 3 linked source(s). Fishori does not fabricate citations.
Fishori uses conservative planning rules based on these sources.
Confidence is explained in the summary at the top of this page (same tier as here), not repeated below.
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.
- Fishori profiles work from typical aquarium trade sizes and hobby care norms. Specialist site checks and literature review for this species are not yet recorded here, so the ranges on this page are planning numbers rather than guarantees.