Max Size: 6.5cm

Pearl Danio (Danio albolineatus, Brachydanio albolineata)

The Pearl Danio is a great beginner fish and ideal for most community aquariums as they are peaceful and pretty adaptable when it comes to their water parameters. Unfortunately, these Danios are highly underrated and are often overlooked by many hobbyists.

Pearl Danios are a naturally shoaling species; therefore, they do better when kept in groups of 6 or more individuals. Depending on your aquarium size and stocking levels, try to keep the highest number of these fish as possible. Individuals within large groups of Pearl Danios will continually chase and interact with one another; this is part of their natural social communications, but don't worry, injuries from these behaviours rarely occur.

If you keep these fish in numbers less than five, the playful chasing seen in larger groups may become stressful for the less dominant individuals. When kept singly, these Danios may become nervous and hover in the top corners of the aquarium.

Tankmates for Pearl Danios are not much of a problem as you can combine them with most other fish in the aquarium hobby. For example, you can house them with medium-sized Cyprinids, Tetras, Livebearers and Rainbowfish, as well as Anabantoids, Catfish and Loaches. You can also use Pearl Danios as a dither fish for many types of smaller, less aggressive Cichlids, such as Kribensis, Keyhole Cichlids and Flag Acaras.

Due to their high activity levels and their shoaling nature, you should not maintain Pearl danios in any aquarium that is less than 75 litres. The larger the aquarium, the better, and these Danios thrive in standard aquariums ranging from 110 to 285 litres. It is also recommended that you keep these Danios in a well-planted aquarium or a setup designed to mimic a flowing stream or river, with a substrate of different sized rocks, gravel and some large smooth boulders.

You can use additional powerheads or filter outlets to provide flow. Still, it would be best if you avoided torrent-like conditions because small Danionins tend to occupy calmer marginal zones and stretches in nature. You could also add some driftwood and hardy aquatic plants such as Microsorum, Anubias or Bolbitis; these are ideal as you can attach them to the decor.

Pearl Danios have a pearl-like sheen on their bodies, and healthy fish will often show various beautiful colour schemes. Most individuals possess an iridescent pink or purple body and a yellow or neon-orange stripe that runs down one third or more of the body length to the caudal fin. These Danios also have yellow or neon-orange eyes, hints of olive on the body, and subtle hints of yellow in their fins.

Quick Facts
Scientific NameDanio albolineatus, Brachydanio albolineata
Other NamesNone
OriginsCambodia, Indonesia, Laos, Malaysia, Myanmar, Thailand, Vietnam
Aquarium LevelMiddle - Top
Best kept asGroups 6+
Lifespan3 - 5 years
Water Parameters
Water TypeFreshwater
PH6.0 - 8.0
GH5 - 19
TDS18 - 357
60 - 77℉
15.6 - 25℃

Photos of the Pearl Danio

Pearl Danio
Pearl Danio
Pearl Danio

Natural Habitat

Pearl Danios are endemic to Myanmar, Sumatra, Cambodia, Laos, Vietnam, Peninsular Malaysia and Thailand in Southeast Asia. In addition, these Danios occur in several major river drainages, including the Mekong, Irrawaddy, Salween, as well as the Chao Phraya and the Mae Klong. These Danios live in various habitat types, from well-oxygenated, clear streams with rocky substrates to forested areas as well as still bodies of water such as ditches, ponds and rice paddies. You can often see them swimming along the surface of the water.

What to feed the Pearl Danio

In the wild, Pearl Danios feed mainly on aquatic and terrestrial insects and their larvae. However, in the aquarium, these Danios are not picky and will accept most food given. Therefore, it would be more beneficial if you provide your fish with a good quality dried product as the diet staple; however, you should supplement this with frequent meals of small live and frozen food such as daphnia, bloodworm and artemia.

How to sex the Pearl Danio

It is quite simple to differentiate between the male and female Pearl Danio. Sexually mature females usually are a little larger, rounder-bellied and slightly less colourful than males. The differences are particularly

clear when the adults are in spawning condition as the males intensify in colour and the female's stomach will fill with eggs.

How to breed the Pearl Danio

Like most Cyprinids, Pearl Danios are an egg-scattering spawner that displays no parental care. If the fish are in excellent condition, they will often spawn, and in a heavily planted, established aquarium, small numbers of fry may start to appear without interference. However, if you would like to increase the number of fry, a slightly more controlled approach will be required.

You may still condition the adult group together, but you will need to set up a separate breeding tank half-filled with water. This tank will need to be dimly lit and the bottom covered with some mesh of a significant enough grade so that eggs can fall through it but small enough that the adults cannot reach them. You can also use artificial grass matting or fine-leaved plants such as java moss; these can also return good results.

The water itself should have a slightly acidic to neutral pH with a slightly higher temperature than the main aquarium. You can add a small power filter initially, which should be positioned in a way that flow is directed down the entire length of the tank.

Once the adults are well-conditioned on live and frozen food and the females appear gravid, you should then introduce one or two pairs into the breeding tank. You may initiate spawning by adding small amounts of cool water every few hours so that the tank is gradually topped up. The pair should then spawn the following morning.

The adults will consume any eggs they find if given a chance, so it would be best to remove them after a couple of days. You should also swap the power filter for a mature sponge-type unit to avoid fry being sucked into it.

The incubation period is temperature-dependent; however, the eggs will usually hatch somewhere between 24 and 36 hours later, and the babies will become free-swimming a few days after that.

It would be best to initially feed the fry with Paramecium or a crushed dry food of sufficiently small size, introducing baby brine shrimp or microworm once the fry is large enough to accept them.

The Pearl Danio has been featured on the following stamps

Vietnam - 1987