Pearl danio

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: any.

Behavior

Plant interaction: plant safe.

Feeding

Eats anything. Flake, micro pellets, frozen bloodworm, frozen brine shrimp, frozen daphnia, live food. Surface and midwater feeder. Not picky, not slow. Feed twice daily. The iridescent pearl coloring shows best on a varied diet.

Compatibility

• Active, peaceful schooling fish. One of the prettier danios but overshadowed by the more widely available zebra danio. Groups of 6+ for proper schooling.
• Compatible with most peaceful community fish: tetras, rasboras, barbs, corydoras, and gouramis. Active swimmers that need horizontal space.
• Tolerates cooler water (18–25°C), making them suitable for subtropical setups alongside white clouds, rosy barbs, and paradise fish.
• Jumpers. Like all danios, they leap when startled or during play. A lid is necessary.

Origin and habitat

Widely distributed across Southeast Asia, with records from Myanmar, Thailand, Laos, Cambodia, Vietnam (including Phu Quoc Island), Peninsular Malaysia, and the island of Sumatra in Indonesia. Occurs in several major river drainages including the Irrawaddy, Salween, Mekong, Mae Klong, and Chao Phraya, plus numerous smaller coastal systems. Found along the surface of small, clear rivers and hill streams. The species name albolineatus means "white-lined" in Latin, referring to the pale stripe along the body. The body has a characteristic iridescent sheen that shifts between blue, pink, and gold depending on the light angle. Grows to a maximum of about 6.6 cm total length. The recorded temperature range is 20–25°C, placing it in the cooler-water category for tropical fish. Golden (semi-albino) varieties are common in the trade. The blue-redstripe form (var. pulcher) and Kedah form (var. tweediei) were once treated as varieties but may be separate valid species. Lifespan around 5 years. Diet in the wild consists of exogenous insects and zooplankton.

Breeding

Easy egg scatterer. Condition a group with frozen food. Breeding tank with fine-leaved plants or spawning mops, temperature at 24–26°C. Spawning occurs at dawn with the group scattering eggs among the plants. Clutch sizes are large (100-300 eggs). Eggs are non-adhesive and fall through the plant mass. Adults eat eggs; remove them after spawning. Eggs hatch in 24-36 hours. Fry take baby brine shrimp within 3-4 days. Growth is fast. Standard danio breeding protocol; no special requirements.

Common problems

Minimal. Pearl danios are hardy and adaptable. Ich in new arrivals is the most common issue; standard treatment works. Jumping is a risk; keep the tank covered. Color can look washed out under bright, cool-white lighting; warm LEDs and a dark substrate bring out the pearl effect. Short lifespan (3-4 years) is typical for small danios.

Outdoor pond suitability

Climate

subtropical

USDA zones

8–12 (winter low around -12°C or warmer)

Outdoor pond at least 60 cm deep for thermal mass. Local frost depth and surface freezing matter.

Bioload

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size