Danio rerio – Zebra Danio – 2 cm

Danio rerio – Zebra Danio

The Danio rerio, commonly known as the Zebra Danio or Zebrafish, is a small Asian fish particularly popular in the aquarium hobby.

It is easily recognised by its silvery body marked with several long dark blue horizontal stripes extending towards the caudal fin. Juveniles may display more subtle colouration, which gradually becomes more contrasting as they grow.

The specimens offered here are approximately 2 cm.

Adult Size of Danio rerio

Adult Danio rerio can reach approximately 4 to 5 cm.

Adult females are generally slightly larger and have a more rounded abdomen, while males are usually more slender.

A Very Active Shoaling Fish

Danio rerio is a sociable, shoaling fish that should be kept in a group.

A group of at least 8 to 10 individuals is recommended. Keeping a sufficiently large group allows the fish to display more of their natural behaviour and helps distribute interactions between individuals.

Danio rerio is particularly active and spends much of its time swimming in the middle and upper levels of the aquarium.

What Size Aquarium Does Danio rerio Need?

Despite its relatively small size, Danio rerio is a fast and very active swimmer. Aquarium length is therefore particularly important.

For an adult group, an aquarium measuring approximately 90 cm in length provides a good basis.

Plants can be positioned along the sides and rear of the aquarium while leaving a sufficiently large open area for swimming.

Water Parameters

Temperature: 18 to 25 °C
pH: 6 to 8
Hardness: approximately 5 to 20 °dGH
Nitrite: 0 mg/L

Danio rerio prefers relatively moderate temperatures. Keeping this species permanently at 28 °C is therefore not recommended.

Nitrite should remain undetectable. Clean, stable and properly filtered water is important for maintaining the fish in good condition.

Feeding Danio rerio

In its natural habitat, Danio rerio feeds on small crustaceans, worms, insect larvae and other small invertebrates.

In the aquarium, it readily accepts good-quality pellets and flakes of a suitable size.

Its diet can be supplemented with Artemia, Daphnia, bloodworms and other suitably sized live or frozen foods.

A varied diet helps keep the fish in good condition and encourages attractive colouration.

Behaviour and Compatibility

Danio rerio is generally a peaceful but extremely active fish.

It can be kept in a community aquarium with many species that have similar requirements, but its constant activity should be taken into account when choosing tank mates.

Very calm or particularly shy species may be disturbed by its energetic behaviour.

Breeding Danio rerio

Danio rerio is an egg-laying fish that scatters its eggs.

During spawning, the eggs are released amongst vegetation or over the substrate. The adults provide no parental care and may eat any eggs they find.

In a densely planted aquarium, some young may occasionally survive. For controlled breeding, the eggs should be protected or the breeding adults removed after spawning.

Origin of Danio rerio

Danio rerio is native to South Asia. Its natural range includes India, Bangladesh and Nepal, with distribution records varying between sources and taxonomic revisions.

In the wild, it inhabits a variety of freshwater environments, including streams, canals, ditches, ponds and seasonally flooded areas.

Lifespan

In the aquarium, Danio rerio generally lives for approximately 3 to 5 years, although some individuals may live longer under suitable conditions.

Conservation Status

Danio rerio is listed as LC – Least Concern on the IUCN Red List.

Never Release Aquarium Fish into the Wild

Aquarium fish must never be released into a river, pond, lake or any other natural environment, in order to protect natural ecosystems and wildlife.

Key Facts About Danio rerio

• scientific name: Danio rerio;
• common names: Zebra Danio and Zebrafish;
• size offered: approximately 2 cm;
• adult size: approximately 4 to 5 cm;
• origin: South Asia;
• very active, sociable shoaling fish;
• group of at least 8 to 10 individuals recommended;
• aquarium approximately 90 cm long recommended for an adult group;
• temperature: 18 to 25 °C;
• pH: 6 to 8;
• varied diet;
• egg-scattering reproduction;
• lifespan: approximately 3 to 5 years;
• IUCN status: LC – Least Concern.