Pearl Danio

Also known as: Danio albolineatus

The Pearl Danio is a small, slender cyprinid known for its iridescent pearl-like sheen along the lateral line, especially visible under aquarium lighting. The Pearl Danio originates from Southeast Asia, specifically found in Myanmar, Thailand, and Malaysia, inhabiting slow-moving streams, rivers, and flooded forest areas with dense vegetation., reaches 5 cm in captivity, typically lives 3, and is kept at 22C (72F). Individual fish vary, so treat this as a general guide rather than a guarantee.

Species at a glance

Origin: Southeast Asia, specifically found in Myanmar, Thailand, and Malaysia, inhabiting slow-moving streams, rivers, and flooded forest areas with dense vegetation.
Adult size: 5 cm (2 in)
Life span: 3
Temperament: Peaceful and active schooling fish; best kept in groups of 6 or more to reduce stress and encourage natural behavior.
Tank size: 40 L (10 gal)
Water temp: 22C (72F)
pH range: pH 6.0-7.5
Diet: Omnivorous; accepts high-quality flake food, micro pellets, and live or frozen foods such as brine shrimp, daphnia, and bloodworms.
Other names: Danio albolineatus

About the Pearl Danio

The Pearl Danio is a small, slender cyprinid known for its iridescent pearl-like sheen along the lateral line, especially visible under aquarium lighting. Native to Southeast Asian freshwater habitats, it thrives in well-planted tanks with gentle water flow. It is a hardy and adaptable species, making it suitable for beginner aquarists when kept in appropriate social groups. Its active swimming behavior adds dynamic movement to community aquariums.

Lifespan and health

With proper care, Pearl Danios typically live 2–3 years in captivity, though exceptional individuals may reach up to 4 years under optimal conditions. Lifespan is strongly influenced by water quality, diet consistency, and stress levels; maintaining stable parameters and a peaceful environment significantly contributes to longevity. Regular observation for signs of illness, such as clamped fins or lethargy, allows for early intervention. Common health issues include ich (white spot disease), often triggered by sudden temperature drops or poor water quality, and fin nipping if kept with aggressive or overly active tankmates. Bacterial infections may occur if water is not regularly changed, manifesting as ulcers or frayed fins. Preventative measures include quarantining new fish, avoiding overstocking, and maintaining ammonia and nitrite at 0 ppm with nitrates below 20 ppm. Prompt treatment with appropriate medications and improved water conditions usually resolves most ailments.

Overview

Care and tank setup

For optimal care, provide a minimum 40-liter (10-gallon) tank for a group of 6 Pearl Danios, with a longer tank preferred over tall to accommodate their active swimming. Use a fine gravel or sand substrate and include dense planting with species like Java moss, Hornwort, or Vallisneria to mimic their natural habitat and provide hiding spots. Maintain gentle filtration to avoid strong currents, as they prefer calm to moderate water flow. Water parameters should be kept stable: temperature between 22–26°C (72–79°F), pH 6.0–7.5, and hardness soft to moderately hard (5–12 dGH). Perform weekly 25% water changes to maintain water quality, and ensure the tank is well-covered as Pearl Danios are known jumpers. Lighting should be moderate to enhance their iridescent coloration without causing stress. Feed small amounts 2–3 times daily, offering only what they can consume within 2–3 minutes to prevent overfeeding and water pollution. A varied diet including high-quality flakes, micro pellets, and 2–3 weekly feedings of live or frozen foods like brine shrimp or daphnia supports vibrant coloration and health. Avoid large or aggressive tankmates that may outcompete them for food.

Adding a Pearl Danio? Research the species’ adult size and temperament carefully, quarantine new fish before introducing them to your tank, and buy from reputable aquarium stores or breeders.

Breed information on this page is based on the Wikipedia article on the Pearl Danio, supplemented with additional research. Reviewed for accuracy.