Blue Danio (Danio kerri) in aquarium
🌿 Freshwater · Tropical

Blue Danio

Danio kerri — Cyprinidae
📏 Size: 4-6
Lifespan: 3-5
Care level: Beginner

Blue Danio Overview

The Blue Danio, also known as the Kerri Danio, is a popular freshwater fish known for its vibrant blue color and peaceful nature. It is a great addition to community tanks and is suitable for beginners. These fish are active and enjoy swimming in groups, though they do not school. They require a well-maintained tank with a temperature range of 22-28°C and a pH level between 6.0 and 8.0.

Quick fact: Danio kerri belongs to the family Cyprinidae. Care level: beginner.

Blue Danio Scientific Classification

RankClassification
FamilyCyprinidae
GenusDanio
SpeciesDanio kerri
Water typefreshwater

Blue Danio Natural Habitat

Native to the Mekong River in Laos, the Blue Danio thrives in slow-moving, warm waters with dense vegetation.

Blue Danio Appearance & Size

The Blue Danio has a slender body with iridescent blue scales and a silver sheen along its sides. It has a distinctive forked tail and a long, flowing dorsal fin.

Coloration: iridescent blue with silver sides

Blue Danio Behavior & Temperament

Blue Danios are generally peaceful and can be kept with a variety of tankmates. However, they may exhibit nipping behavior towards tankmates, especially during breeding season. They are active swimmers and enjoy the company of other fish.

TraitValue
Temperamentpeaceful community fish
SchoolingNo
Activity levelmoderate
Important: occasionally nippy with tankmates

Blue Danio Water Requirements

ParameterIdeal RangeNotes
Temperature2228°C (7282°F)Use a reliable adjustable heater
pH68Avoid sudden swings
Hardness (GH)5-15 dGH dGHSoft to moderately hard
Ammonia0 ppmAny detectable ammonia signals a problem
Nitrite0 ppmToxic even at low levels
Nitrate<20 ppmManage through regular partial water changes
Min. tank20L (5 gal)Larger tanks are easier to keep stable
Important: Always dechlorinate tap water before adding it to the tank. Chlorine and chloramines damage a fish's gills and reduce life expectancy.

Interesting Facts About Blue Danio

  • Blue Danios are one of the most commonly bred aquarium fish.
  • They are known for their ability to change color based on their mood and environment.
  • The species is an important food source for many local communities in its native range.

Related Species & Guides

Editorial review

This species profile was reviewed for biological accuracy and practical aquarium care guidance. For suspected illness or disease, test your water parameters first and consult an aquatic veterinarian if symptoms persist.