Max Size: 4.5cm

Blue Danio (Danio kerri)

Blue Danios are a peaceful and hardy species that can adapt to various water conditions, making them suitable for the beginner aquarist. In addition, these Danios are friendly fish that won't disturb or hurt anything too large to be eaten. These Danios are relatively common in the aquarium trade, and you should be able to find them if you want them.

Blue Danios are shoaling fish in nature; therefore, you should keep them in groups of 8 or more individuals. Maintaining these Danios in decent numbers will not only make the fish less skittish but will also result in a far more effective, natural-looking display. At the same time, males will also display their best colours as they contend with one other for female attention.

Blue Danios have no particular demands when it comes to water chemistry; therefore, you can combine them with the most popular fish in the aquarium hobby. Tankmates could include other small Cyprinids, Tetras, Livebearers and Rainbowfish, as well as Loaches and Catfish.

The ideal aquarium setup for Blue Danios would be a heavily planted aquarium designed in such a way to mimic a flowing stream or river with a darker substrate, as they may appear paler in a sparsely decorated aquarium. Adding gravel, smooth stones or different sized rocks will also add to the effect. In addition, driftwood branches and roots, along with some aquatic plants, with hardy genera such as Anubias, Bolbitis or Microsorum, are ideal because they can be grown attached to the decor.

Blue Danios prefer clean well-oxygenated water; therefore, good filtration is essential. The aquarium needs to be set up in such a way that they have a current of water flowing from one end to the other against which these Danios will constantly swim. Filter outlets or additional powerheads will help provide flow; however, it would be best to avoid torrent-like conditions because these Danios usually occupy calmer stretches in nature.

You will need to have a tight-fitting lid on the aquarium as members of this genus are excellent jumpers and can fit through tiny gaps.

Blue Danios have slightly deep torpedo-shaped bodies that are either powdery-blue or yellowish-green, continuing into the caudal fin, depending on their location. These Danios also possess some pinkish-gold lateral stripes that extend from their opercle to their caudal peduncle.

It might be helpful to know that populations from different localities vary in body colouration; for example, fish from the northern end of the range tend to be more of a blue colour, while those from the south are typically more yellowish.


Blue Danio
Blue Danio
Blue Danio
Quick Facts
Scientific NameDanio kerri
Other NamesKerr's Danio, Turquoise Danio
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
Best kept asGroups 8+
Lifespan3 - 5 years
Water Parameters
Water TypeFreshwater
PH6.5 - 7.5
GH8 - 12
TDS36 - 215
72 - 78℉
22.2 - 25.6℃


In the home aquarium, the Blue Danio will readily accept most good quality dried foods such as granules, flakes and sinking pellets. These modern food products have been developed to provide all adequate nutrition to maintain your fish's health and dietary requirements.

Providing additional foodstuffs such as live, frozen, and freeze-dried meals such as bloodworm, daphnia, and tubifex once or twice a week will provide additional benefits to your fish's health and well-being but is not a must for this fish.

It should be noted that bloodworms should only be given as an occasional treat and should not be used as the staple diet as they are difficult for fish to digest and can potentially cause blockages.

This fish is an omnivore in the wild, meaning it will consume some vegetable matter. Although most modern fish foods take this into account and include them in their products, you can still supplement your fish's diet with blanched vegetables such as spinach, broccoli, and zucchini. Ensure you do not overfeed your fish and remove any leftovers the following day.

Sexual Dimorphism

It is relatively straightforward to distinguish the males from the female Blue Danios. Adult males are slightly smaller and slimmer than females and are more vibrantly coloured. In contrast, Sexually mature females are usually larger, more rounded in their abdomens and duller than males. The differences are apparent when the fish are in spawning conditions.

Other Danios of interest

Assam Danio(Devario assamensis)
Barred Danio(Devario pathirana)
Bengal Danio(Devario devario)
Black Barred Danio(Danio absconditus)
Blood Tailed Danio(Devario annandalei)
Celestial Pearl Danio(Danio margaritatus)
View all Danios
Date Added: 09/12/2021 14:52:53 - Updated: 11/08/2022 14:58:59