Blue danio

Danio kerri

FreshwaterFish

Care at a glance

Temperature: 68–79°F (20–26°C)
pH: 6.0–7.5
Adult size: 1.8 in (4.5 cm)
Minimum tank: 11 gal (40 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Beginner
Breeding: Medium
Rarity: Rare
Origin: Thailand
Family: Cyprinidae

Overview

Keep them in a group of six or more, ideally more, since they settle down and look better in numbers. They're fast, active swimmers that hang in the upper half of the tank. Aim for around 40 liters minimum, pH from 6 to 7.5, and temperatures between 20 and 26 C. They're peaceful and easy to feed: good flake, small pellets, and frozen brine shrimp or daphnia a few times a week.

In the wild

Blue danios come from clear, gently flowing streams in Thailand and nearby parts of Southeast Asia, often over sand and rock with plants along the edges. The water there runs soft and a little acidic to neutral. Give them open swimming room up top, some current from the filter, and a temperature in the low to mid 20s C.

Good to know

This is a small cyprinid, reaching about 4 to 5 cm as an adult. It's an egg scatterer with no parental care, and eggs usually hatch in a day or so. Wild stocks are stable, though deforestation and pollution are the usual long-term concerns for stream fish like this one.

Did you know

Danio kerri was first described from Thailand's Ko Yao islands, and it's a close relative of the zebra danio. The two will sometimes hybridize in aquariums if you keep them together without enough of their own kind.