Blue Danio (Danio kerri) Care Guide
Danio kerri is a powder-blue danio from islands off the Thai-Malay coast, with gold lines and active, peaceful shoaling behaviour.
Compiled by Aquairi from published sources · Published · Updated
Overview
Danio kerri, the blue danio, was described by H. M. Smith in 1931. It is a deep-bodied, powder-blue danio marked with several pinkish-gold lines running from tail to gills, which may be continuous or broken. It is an active, peaceful shoaling fish.
Taxonomy
- Family: Cyprinidae
- Genus: Danio
- Scientific name: Danio kerri
- Described by: H. M. Smith, 1931
- Common synonym: Brachydanio kerri
Habitat
It is found on the islands of Langkawi and Ko Yao Yai in the Thai-Malay region.
Tank requirements
- Minimum tank volume: 80 L
- Temperature: 20-25 °C (68-77 °F)
- pH: 6.5-7.5
- GH: 5-15 °dGH
- School size: at least 6 individuals
- Lifespan: 3-5 years
An active species, it appreciates a long aquarium with moderate flow and tends to prefer slightly cooler water within the danio range.
Diet
Like other small danios it is omnivorous, accepting dried foods and benefiting from small live or frozen foods such as Daphnia and Artemia.
Compatibility
It is peaceful, active and prefers group living, so it should be kept in shoals of at least six with other peaceful, similarly sized fish; aggressive species should be avoided.
Breeding
It spawns at dawn over coarse gravel, scattering eggs that hatch approximately 36 hours after deposition; no parental care is given.
Blue Danio (Danio kerri) Breeding Guide
Overview
Danio kerri is a small iridescent danio that reaches around 40-45 mm in standard length. It is an egg-scattering cyprinid with no parental care; in established, densely-planted tanks fry may appear naturally, but a controlled setup yields far more reliable results.
Sexing
Sexually mature females are usually rounder-bellied, slightly less colourful and a little larger than males, and the difference becomes especially pronounced once the fish are in spawning condition.
Conditioning
Condition adults together on live and frozen foods until females fill with roe. Well-fed fish come into condition quickly and respond strongly to the spawning triggers described below.
Breeding Setup
Use a small container of about 30-40 litres filled only halfway. Provide a spawning medium such as Java moss, wool mops, or a spawning grid so eggs can settle out of reach. Keep the water slightly acidic to neutral and toward the upper end of the temperature range. Swap any power filter for a sponge unit to protect the fry from suction.
Spawning Behavior & Trigger
Spawning can be triggered by adding small amounts of cool water every few hours, or by a large 50-60% water change combined with feeding live and frozen foods. The fish scatter eggs over the medium during this activity.
Egg & Fry Care
Adults will consume the eggs and should be removed as soon as any are spotted. Incubation usually takes 24-36 hours, with the young free-swimming a few days later. First foods are Artemia nauplii or similar small live foods.
Common Challenges
The main risks are egg predation by the parents and fry being lost to filter intakes; both are addressed by a suitable spawning medium, prompt removal of adults, and sponge filtration. Clean, stable water supports the delicate free-swimming stage.