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
- 18 gal
- 70 L
- Temperament
- Peaceful
- Social behavior
- Schooling
- Swim level
- Middle
- Difficulty
- Beginner
- Breeding
- Egg scatterer · Medium
- Rarity
- Rare
- Family
- Cyprinidae
- Origin
- Thailand
Overview
The blue danio is a small, fast schooling fish for a peaceful community tank. It is easy to keep and makes a good first fish.
Did you know
The blue danio is a close relative of the zebra danio, and the two sometimes hybridize in aquariums. That happens when they are kept together without enough of their own kind.
Caring for the blue danio
Keep blue danios in a group of at least six, and more if you can. They settle down and look better in numbers. Give them 18 gal (70 L) or more, with open swimming room and some current from the filter.
Keep the water at 68 to 79°F (20 to 26°C) and a pH of 6.0 to 7.5. They are easy to feed. Give them good flake and small pellets, plus frozen brine shrimp or daphnia a few times a week.
Blue danios are peaceful, fast, active swimmers, and they stay in the middle of the tank. They are egg scatterers with no parental care, and the eggs usually hatch in a day or so. Breeding them is a moderate challenge.
Good to know
The blue danio, Danio kerri, is a small cyprinid first described from the Ko Yao islands of Thailand. Wild stocks are stable, though deforestation and pollution are the usual long-term concerns for stream fish like this one.
In the wild
Blue danios come from clear, gently flowing streams in Thailand and nearby parts of Southeast Asia. They often live over sand and rock, with plants along the edges. The water there runs soft and a little acidic to neutral.
Weekly picks
Tank mates
The blue danio is a peaceful, schooling species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.
Neocaridina shrimp
Neocaridina davidi
Freshwater1.6 in (4 cm) · 5 gal (19 L)59–84°F (15–29°C)
Guppy
Poecilia reticulata
FreshwaterBrackish2.4 in (6 cm) · 10 gal (38 L)64–82°F (18–28°C)
Neon tetra
Paracheirodon innesi
Freshwater1.5 in (3.8 cm) · 11 gal (40 L)70–77°F (21–25°C)
Xingu cory
Hoplisoma xinguense
Freshwater2 in (5 cm) · 18 gal (70 L)72–81°F (22–27°C)
Blue panchax
Aplocheilus panchax
Freshwater3.5 in (9 cm) · 20 gal (75 L)72–82°F (22–28°C)
Striped nannacara
Nannacara taenia
Freshwater2.4 in (6 cm) · 18 gal (70 L)75–82°F (24–28°C)
Common questions
What size tank does a blue danio need?
A blue danio needs at least 18 gal (70 L). It spends most of its time in the middle.
What temperature and pH does a blue danio need?
A blue danio is comfortable at 68–79°F (20–26°C) with a pH of 6.0–7.5.
What does a blue danio eat?
A blue danio eats good flake and small pellets. Add frozen brine shrimp or daphnia a few times a week.
How big does a blue danio get?
An adult blue danio reaches about 1.8 in (4.5 cm).
Does a blue danio need a group?
Yes. A blue danio is a schooling species and should be kept in a group, not singly.
How does a blue danio breed?
Blue danios scatter their eggs and give no parental care. The eggs usually hatch in a day or so, and breeding them is a moderate challenge.
Related species
1.5 in (3.7 cm)15 gal (55 L)64–79°F (18–26°C)Spotted danio
Danio nigrofasciatus
1.5 in (3.7 cm) · 15 gal (55 L)
2.4 in (6 cm)18 gal (70 L)61–77°F (16–25°C)Pearl danio
Danio albolineatus
2.4 in (6 cm) · 18 gal (70 L)
1.2 in (3 cm)11 gal (40 L)64–79°F (18–26°C)Gold ring danio
Danio tinwini
1.2 in (3 cm) · 11 gal (40 L)
2 in (5 cm)11 gal (41 L)64–75°F (18–24°C)Zebra danio
Danio rerio
2 in (5 cm) · 11 gal (41 L)
0.8 in (2 cm)9 gal (35 L)72–79°F (22–26°C)Celestial Pearl danio
Danio margaritatus
0.8 in (2 cm) · 9 gal (35 L)
0.8 in (2 cm)11 gal (40 L)68–75°F (20–24°C)Emerald dwarf rasbora
Danio erythromicron
0.8 in (2 cm) · 11 gal (40 L)