Photo: Sc99cs at English Wikipedia (Original text: Steven Coburn sc99cs) (Public domain) — via Wikimedia Commons
Pearl Danio (Danio albolineatus)
A shimmering, ice-blue shoaler built for beginners: fast, forgiving, and stunning in a group of six or more.
Will it live with a Pearl Danio?
We compare each fish against your pearl danio on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Adolf's Cory✅ CompatiblePeaceful · 5.5 cm · Medium care · 22–26 °C (72–79 °F)
- Both are peaceful, and their water overlaps around 22–25 °C — no size, zone or temperament conflicts.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Adolf's Cory in a shoal of 6+ or it gets stressed and nippy.
- Agassiz's Corydoras✅ CompatiblePeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 22–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Agassiz's Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Blackline Rasbora✅ CompatiblePeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 22–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Blood Red Tiger Pleco✅ CompatiblePeaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
- Compatible on the things that matter: shared water near 24–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Bloodfin Tetra✅ CompatiblePeaceful · 5.5 cm · Easy care · 18–28 °C (64–82 °F)
- Compatible on the things that matter: shared water near 20–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Bloodfin Tetra in a shoal of 6+ or it gets stressed and nippy.
- Butterfly Hillstream Loach✅ CompatiblePeaceful · 6 cm · Hard care · 18–24 °C (64–75 °F)
- Compatible on the things that matter: shared water near 20–24 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Celebes Rainbowfish✅ CompatiblePeaceful · 7 cm · Medium care · 22–28 °C (72–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Celebes Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Corydoras Catfish✅ CompatiblePeaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Corydoras Catfish in a shoal of 6+ or it gets stressed and nippy.
- Diamond Tetra✅ CompatiblePeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Diamond Tetra in a shoal of 6+ or it gets stressed and nippy.
- Duplicareus Corydoras✅ CompatiblePeaceful · 5.5 cm · Medium care · 23–27 °C (73–81 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Duplicareus Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Elegant Cory✅ CompatiblePeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Elegant Cory in a shoal of 6+ or it gets stressed and nippy.
- False Julii Corydoras✅ CompatiblePeaceful · 6 cm · Easy care · 22–26 °C (72–79 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep False Julii Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Glass Bloodfin Tetra✅ CompatiblePeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Glass Bloodfin Tetra in a shoal of 6+ or it gets stressed and nippy.
- Guppy✅ CompatiblePeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the top of the tank — offer enough cover so they aren't always in each other's space.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Hillstream Loach✅ CompatiblePeaceful · 6 cm · Hard care · 20–24 °C (68–75 °F)
- Compatible on the things that matter: shared water near 20–24 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Narcissus II Cory✅ CompatiblePeaceful · 5.5 cm · Medium care · 22–26 °C (72–79 °F)
- Both are peaceful, and their water overlaps around 22–25 °C — no size, zone or temperament conflicts.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Narcissus II Cory in a shoal of 6+ or it gets stressed and nippy.
- Neon Dwarf Rainbowfish✅ CompatiblePeaceful · 6 cm · Easy care · 23–27 °C (73–81 °F)
- Compatible on the things that matter: shared water near 23–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Neon Dwarf Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Panda Loach✅ CompatiblePeaceful · 6 cm · Hard care · 18–23 °C (64–73 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Platy✅ CompatiblePeaceful · 6 cm · Easy care · 21–28 °C (70–82 °F)
- Both are peaceful, and their water overlaps around 21–25 °C — no size, zone or temperament conflicts.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Rust Corydoras✅ CompatiblePeaceful · 5.5 cm · Easy care · 23–27 °C (73–81 °F)
- Both are peaceful, and their water overlaps around 23–25 °C — no size, zone or temperament conflicts.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Rust Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Samurai Gourami✅ CompatiblePeaceful · 6 cm · Hard care · 24–28 °C (75–82 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Slate Corydoras✅ CompatiblePeaceful · 6 cm · Medium care · 23–28 °C (73–82 °F)
- Compatible on the things that matter: shared water near 23–25 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Slate Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Spotfin Corydoras✅ CompatiblePeaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Spotfin Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Sterbai Corydoras✅ CompatiblePeaceful · 6.5 cm · Medium care · 24–30 °C (75–86 °F)
- Both are peaceful; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Sterbai Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Ash Lipped Apisto⚠️ With cautionSemi-aggressive · 7 cm · Hard care · 24–29 °C (75–84 °F)
- Ash Lipped Apisto and Pearl Danio are close in size, but the semi-aggressive one tends to dominate — add pearl danio in a group to spread the pressure.
- Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Banded Dwarf Cichlid⚠️ With cautionSemi-aggressive · 7 cm · Medium care · 24–30 °C (75–86 °F)
- Banded Dwarf Cichlid and Pearl Danio are close in size, but the semi-aggressive one tends to dominate — add pearl danio in a group to spread the pressure.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Betta⚠️ With cautionSemi-aggressive · 6.5 cm · Easy care · 24–28 °C (75–82 °F)
- Betta and Pearl Danio are close in size, but the semi-aggressive one tends to dominate — add pearl danio in a group to spread the pressure.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Black Ruby Barb⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 22–26 °C (72–79 °F)
- Black Ruby Barb and Pearl Danio are close in size, but the semi-aggressive one tends to dominate — add pearl danio in a group to spread the pressure.
- Your 75 L tank is below the ~100 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Black Ruby Barb in a shoal of 6+ or it gets stressed and nippy.
- Black Skirt Tetra⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 20–26 °C (68–79 °F)
- Black Skirt Tetra and Pearl Danio are close in size, but the semi-aggressive one tends to dominate — add pearl danio in a group to spread the pressure.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Bleeding Heart Tetra⚠️ With cautionSemi-aggressive · 7 cm · Medium care · 23–28 °C (73–82 °F)
- Expect Bleeding Heart Tetra to harass Pearl Danio at times; give dense cover and watch them at feeding.
- Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Bleeding Heart Tetra in a shoal of 6+ or it gets stressed and nippy.
- Bright Diamond Tetra⚠️ With cautionPeaceful · 7 cm · Hard care · 24–28 °C (75–82 °F)
- Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Bright Diamond Tetra in a shoal of 8+ or it gets stressed and nippy.
- Colombian Tetra⚠️ With cautionSemi-aggressive · 6.5 cm · Easy care · 24–28 °C (75–82 °F)
- Colombian Tetra is semi-aggressive and may chase or nip the smaller Pearl Danio — plant heavily and break up sight lines.
- Your 75 L tank is below the ~114 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Colombian Tetra in a shoal of 6+ or it gets stressed and nippy.
- Desert Goby⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 18–28 °C (64–82 °F)
- Expect Desert Goby to harass Pearl Danio at times; give dense cover and watch them at feeding.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Dwarf Chain Loach⚠️ With cautionPeaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
- Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Dwarf Chain Loach in a shoal of 6+ or it gets stressed and nippy.
- Eastern Betta⚠️ With cautionSemi-aggressive · 6 cm · Medium care · 24–28 °C (75–82 °F)
- Eastern Betta and Pearl Danio are close in size, but the semi-aggressive one tends to dominate — add pearl danio in a group to spread the pressure.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- GloFish Tetra⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 21–28 °C (70–82 °F)
- Expect GloFish Tetra to harass Pearl Danio at times; give dense cover and watch them at feeding.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep GloFish Tetra in a shoal of 6+ or it gets stressed and nippy.
- Odessa Barb⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 20–26 °C (68–79 °F)
- Expect Odessa Barb to harass Pearl Danio at times; give dense cover and watch them at feeding.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Keep Odessa Barb in a shoal of 6+ or it gets stressed and nippy.
- Peaceful Betta⚠️ With cautionSemi-aggressive · 6 cm · Medium care · 24–28 °C (75–82 °F)
- Peaceful Betta is semi-aggressive and may chase or nip the smaller Pearl Danio — plant heavily and break up sight lines.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Smaragd Betta⚠️ With cautionAggressive · 6 cm · Medium care · 23–28 °C (73–82 °F)
- Smaragd Betta is aggressive and may chase or nip the smaller Pearl Danio — plant heavily and break up sight lines.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Three-striped Dwarf Cichlid⚠️ With cautionSemi-aggressive · 6 cm · Medium care · 23–29 °C (73–84 °F)
- Expect Three-striped Dwarf Cichlid to harass Pearl Danio at times; give dense cover and watch them at feeding.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Alligator Gar⛔ Not recommendedAggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
- Pearl Danio is bite-sized to a 250 cm predatory alligator gar — it will be eaten.
- Alligator Gar is aggressive and may chase or nip the smaller Pearl Danio — plant heavily and break up sight lines.
- Your 75 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Clown Knifefish⛔ Not recommendedAggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
- Pearl Danio is bite-sized to a 90 cm predatory clown knifefish — it will be eaten.
- Expect Clown Knifefish to harass Pearl Danio at times; give dense cover and watch them at feeding.
- Your 75 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Fire Eel⛔ Not recommendedSemi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
- Size gap is too large (100 vs 6 cm): Fire Eel will treat Pearl Danio as food.
- Expect Fire Eel to harass Pearl Danio at times; give dense cover and watch them at feeding.
- Your 75 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Koi⛔ Not recommendedPeaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
- Size gap is too large (90 vs 6 cm): Koi will treat Pearl Danio as food.
- Your 75 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Redtail Catfish⛔ Not recommendedAggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
- Size gap is too large (120 vs 6 cm): Redtail Catfish will treat Pearl Danio as food.
- Expect Redtail Catfish to harass Pearl Danio at times; give dense cover and watch them at feeding.
- Your 75 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Spotted Gar⛔ Not recommendedAggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
- Size gap is too large (90 vs 6 cm): Spotted Gar will treat Pearl Danio as food.
- Expect Spotted Gar to harass Pearl Danio at times; give dense cover and watch them at feeding.
- Your 75 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Wels Catfish⛔ Not recommendedAggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
- Size gap is too large (300 vs 6 cm): Wels Catfish will treat Pearl Danio as food.
- Wels Catfish is aggressive and may chase or nip the smaller Pearl Danio — plant heavily and break up sight lines.
- Your 75 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Wolf Cichlid⛔ Not recommendedAggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
- Pearl Danio is bite-sized to a 72 cm predatory wolf cichlid — it will be eaten.
- Wolf Cichlid is aggressive and may chase or nip the smaller Pearl Danio — plant heavily and break up sight lines.
- Your 75 L tank is below the ~760 L this pairing really wants — crowding raises aggression.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
Compatibility is computed from each species' care data — a strong starting point, not a guarantee. Individual temperament varies, so always introduce new fish slowly and watch them.
Pearl Danio care specs
- Care level
- Easy
- Breeding
- Easy
- Max size
- 6 cm (2.4 in)
- Min tank size
- 60 L (15.9 gal)
- Temperature
- 20–25 °C (68–77 °F)
- pH
- 6–7.8
- Hardness
- 4–18 dGH
- Lifespan
- 3–5 years
- Diet
- Omnivore
- Swim level
- Top
- Group size
- 6+ (shoaling)
- Family
- Cyprinidae
- Origin
- Myanmar, Sumatra, and mainland Southeast Asia — rivers and streams of low to moderate current
What is a Pearl Danio?
The pearl danio (Danio albolineatus) is a small, quick-moving cyprinid from mainland Southeast Asia, valued for its soft iridescent sheen and genuinely easygoing nature. At full size it reaches around 6 cm (2.4 in), with a slender, torpedo-shaped body that catches light in shifting tones of silver-blue and, along the lateral line, a flush of pale pink to orange that intensifies in well-conditioned fish.
Unlike many fish labelled “beginner-friendly,” the pearl danio earns the description honestly. It tolerates a wide temperature band, adapts to a broad range of water chemistries, and eats almost anything offered. Its one firm requirement: it is a shoaling species and must be kept in a group of at least six. A lone pearl danio will hide, pale out, and decline — a proper shoal turns a tank into a display of constant, coordinated motion.
Where do Pearl Danios come from?
Pearl danios originate from Myanmar, Sumatra, and the river systems of mainland Southeast Asia — clear, well-oxygenated streams and shallow upland rivers of low to moderate current, with sandy substrates and dappled riparian light.
The water is generally soft to moderately hard and close to neutral in pH, though conditions vary with season and altitude. Pearl danios prefer cooler temperatures than most tropical cyprinids, moderate water movement, open swimming lanes and some surface cover from floating plants.
What size tank does a Pearl Danio need?
The minimum practical tank size is 60 L (16 gal) for a starter group of six. Because pearl danios are open-water swimmers that move fast and horizontally, tank footprint matters more than height — a long, shallow tank serves them better than a tall column of the same volume. A 75–90 L (20–24 gal) tank with a 90 cm (36 in) footprint gives eight to ten fish the room to school properly.
Provide a tight-fitting lid: pearl danios will jump if startled. Filtration should deliver moderate flow — they come from moving water and appreciate a gentle current — but avoid a spray bar that churns the entire tank. Leave open upper and midwater swimming lanes, with planting around the edges and back for cover and contrast.
What water parameters do Pearl Danios need?
- Temperature: 20–25 °C (68–77 °F). This is notably cooler than most tropical community fish — pearl danios thrive at the lower end of the “tropical” range and are one of the few species that can be kept in a well-placed room-temperature setup in mild climates. Avoid sustained temperatures above 26 °C.
- pH: 6.0–7.8. A wide tolerance; mid-neutral is ideal.
- Hardness: 4–18 dGH — soft to moderately hard.
Stability is the priority. Pearl danios are hardy, but sudden swings in temperature or chemistry stress any fish. Cycle the tank fully before adding them, keep up with weekly partial water changes of around 25–30 %, and match new water temperature before adding it. Clean, well-oxygenated water brings out the full intensity of their iridescence.
What do Pearl Danios eat?
Pearl danios are omnivores with a strong surface-feeding instinct — in the wild they pick insects, small invertebrates and plant material from the upper water column. In the aquarium they accept a wide variety of foods:
- Staple: High-quality micro-pellets or fine flake for small cyprinids.
- Variety: Frozen or live daphnia, baby brine shrimp and bloodworm are taken eagerly and help condition fish for breeding.
- Supplemental: Spirulina-enriched foods support the iridescent pigments.
Feed small amounts two to three times a day. Pearl danios are fast, competitive feeders, so check that calmer tankmates get their share.
Are Pearl Danios aggressive — and what fish can live with them?
Pearl danios are peaceful by temperament and make excellent community fish. They pose no serious threat to tankmates — they are not fin-nippers in the chronic sense — though a group moving at speed around a solitary, slow-finned fish like a betta or a fancy guppy can cause enough stress to warrant separation. Their energy level is the only compatibility consideration, not aggression.
Good tankmates include corydoras catfish, small rasboras, tetras, livebearers (standard-finned varieties), and other danio species. Because pearl danios are top-dwellers, pairing them with mid- and bottom-oriented species fills the tank evenly. Avoid large predatory fish — anything that can fit a 6 cm fish in its mouth will try.
For a detailed, filterable list of what pairs well and what to avoid, see Pearl Danio tank mates.
How do you tell male and female Pearl Danios apart?
Sexing pearl danios is reasonably straightforward in a conditioned group. Females are slightly larger and noticeably rounder-bodied, particularly when carrying eggs — the abdomen becomes visibly full as they come into condition. Males are slimmer and more streamlined, and they develop a stronger pink-to-orange flush along the lateral line, especially when actively chasing females or displaying to rivals within the shoal.
The difference is most visible when the fish are well-fed and the water temperature is at the warmer end of their range. In juvenile fish the distinction is subtle; wait until they reach around 3–4 cm before attempting to sex them reliably.
How do Pearl Danios breed?
Pearl danios are egg-scatterers that breed willingly in captivity — they are often recommended as a first spawning project for hobbyists new to egg-layer breeding. The process is straightforward:
Condition a small group (two males per female works well) with live or frozen foods for one to two weeks. Set up a shallow breeding tank — 20–40 L is sufficient — with a fine-leaved plant or spawning mop on the bottom and slightly cooler, soft water. Add the conditioned fish in the evening; spawning typically occurs the following morning, triggered by the first light.
Eggs are adhesive and sink into the mop or plant. Remove the adults immediately after spawning — they will eat the eggs. Eggs hatch in approximately two to three days at 22 °C; fry become free-swimming shortly after and accept infusoria, commercial fry food or freshly hatched baby brine shrimp. Fertility is typically high, with clutch sizes of 100–300 eggs common.
What are common Pearl Danio diseases?
Pearl danios are robust fish and do not have species-specific vulnerabilities beyond the standard freshwater concerns:
- Ich (white spot): Fine white dots on the body and fins, often triggered by a sudden temperature drop or adding an unquarantined fish. Prevention is straightforward — maintain stable temperature, quarantine all new arrivals for two to four weeks before adding them to the display tank.
- Fin rot: Frayed or receding fin edges, almost always a water-quality issue. Regular water changes and avoiding overcrowding prevent it in most cases.
- Velvet (Oodinium): A dusty or golden-yellow sheen, often first noticed on the head. Early detection is key; it spreads fast in a shoal. Strict quarantine of new fish is the main preventive.
- Internal parasites: Wasting despite a good appetite can indicate intestinal worms, occasionally introduced via live foods. Sourcing live foods from reputable suppliers reduces the risk.
Health note: a care profile is not a treatment guide. Before medicating, confirm the diagnosis against a reputable veterinary or fish-health source — many symptoms overlap between conditions, and the wrong treatment can make things worse.
How long do Pearl Danios live?
With good care, pearl danios live 3–5 years. The keys to reaching that upper end are consistent water quality, a varied diet, a large enough group to allow normal social behaviour, and a tank temperature held at the cooler end of their range — warmth accelerates metabolism and shortens lifespan in small fish. A shoal bought as juveniles and maintained well can remain a lively, colourful centrepiece of a community tank for several years.
Frequently asked questions
How many pearl danios should I keep together?
Keep at least six — they are active schooling fish and become timid and stressed in smaller numbers. A group of eight to ten in a 75–90 L tank gives the best display, with the fish constantly moving together in tight formation. The more swimming room you give them, the more dramatic the schooling behaviour.
Are pearl danios compatible with other community fish?
Yes. Their peaceful temperament and fast movement make them a near-universal community choice. Pair them with other calm mid-to-small fish — corydoras, tetras, rasboras, livebearers — in soft-to-moderately-hard water. Avoid slow, long-finned tankmates like bettas or fancy guppies, as danios are energetic enough to stress them even without nipping.
What you need to keep a pearl danio
The baseline is a heated, filtered 60 L+ tank: a reliable heater to hold 20–25 °C (68–77 °F), a gentle filter that won't batter a pearl danio in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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