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Passport
- Family
- Danios / Whiteclouds / Medakas
- Grows to
- 5 cm (2")
- Lives
- 3–5 years
- Temperament
- Peaceful
- Care
- Beginner
- Swims
- Near the surface
- Keep
- In a group of 8 or more
- Water
- 18–25 °C (64–77 °F)
India
Care requirements
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On record for Zebra Danio: adult size, lifespan, minimum tank, temperature, ph, hardness, minimum group, diet, care level, swim level, tank length.
A figure that is not on record is left out rather than guessed. One marked Suggested comes from keeping knowledge rather than a page.
- Minimum tank 57 L / 15.0 US gal
- pH 6–8
- Hardness 5–20 dGH
- Diet micropredator
- Tank length 90 cm minimum
Care notes written from general aquarium knowledge, not from the cited sources.
About
Fast, tough and very nearly impossible to kill, which is why they're the standard advice for a first tank and why they're so often kept badly. A zebra danio will survive conditions that would finish most tropical fish, and "survive" is doing a lot of work in that sentence.
They're relentless swimmers. Put them in a small tank and they pace; put them in too small a group and they turn that energy on each other and on the fins of anything slower.
The wild form is a small striped fish. The long-finned and dyed varieties sold alongside it are the same species, and they swim considerably worse.
Tank setup
Give them length above all else. This is the fish where a long, shallow tank genuinely beats a tall one of the same volume — they need a run to swim down, not depth.
Get the numbers right. A proper group settles them, and a few individuals turn nippy and nervous. This is the most reliable fix for danio behaviour problems and it's almost always the answer.
Put a lid on it. They're surface-oriented, quick, and they jump.
Keep them cooler than most tropical fish. They come from subtropical water and are one of the few species that genuinely doesn't want a warm tropical tank all year — a heater set for a community of tetras sits at the top of their comfortable range, not in the middle of it.
Feeding
Danios are unfussy and enthusiastic about everything. Flake, micro pellets, frozen daphnia and bloodworm all get taken readily, usually at the surface, and fast.
They'll outcompete almost anything slower, and in a mixed tank that's the main practical problem with them. Feed in more than one spot, and check the slower fish are getting anything at all.
Avoid: overfeeding, which is easy because they always act hungry.
Filtration and flow
They like flow, which is unusual and worth taking advantage of — a stronger outflow gives them something to swim against and settles them down.
Keep the water well oxygenated. Otherwise they're undemanding on filtration, and hardy enough that people cycle tanks with them, which is a practice worth avoiding on its own terms rather than because they can't take it.
With plants
Safe with plants, and fairly indifferent to them. They won't dig or eat anything, but they use open water rather than cover, so the planting is for the tank's sake more than for theirs.
Plant the edges and leave the middle clear. A heavily planted tank with no swimming lane suits nearly every other community fish better than it suits a danio.
Health
They're genuinely hardy, and most of their problems are consequences of the tank rather than pathogens.
Fin damage is the common one, and in a danio tank it's usually self-inflicted by the group — an undersized shoal nips. Increase the numbers before you treat anything.
The long-finned varieties are noticeably weaker swimmers and correspondingly more prone to being nipped and to trailing fin rot.
They're used as laboratory animals, which means their diseases are unusually well documented. Mycobacteriosis in particular shows up as wasting and spinal curvature with no obvious external cause, and it isn't treatable.
Breeding
This happens readily, and they're among the easiest egg-scatterers to spawn on purpose. They scatter over a substrate and then eat the eggs immediately afterwards with obvious enthusiasm.
The standard approach is a bare tank with marbles or a mesh for the eggs to fall through, and removing the adults the moment spawning finishes. The fry are free-swimming within days and grow quickly.
None of it needs soft water or special conditions, which is a fair summary of the species generally.
Tank mates
Avoid8
- Convict Cichlid Convict Cichlid grows to 15 cm against Zebra Danio at 5 cm, big enough to eat it.
- Jewel Cichlid Jewel Cichlid grows to 15 cm against Zebra Danio at 5 cm, big enough to eat it.
- Least Killifish Zebra Danio grows to 5 cm against Least Killifish at 2 cm, big enough to eat it.
- Scarlet Badis Zebra Danio grows to 5 cm against Scarlet Badis at 2 cm, big enough to eat it.
- Demasoni Cichlid Demasoni Cichlid is not safe with Zebra Danio: african cichlids and danios / whiteclouds / medakas are a bad pairing.
Only with care17
- Chinese Algae Eater Chinese Algae Eater is aggressive and Zebra Danio is peaceful.
- Agassiz's Dwarf Cichlid Zebra Danio and Agassiz's Dwarf Cichlid are an uneasy mix: danios / whiteclouds / medakas and sth american cichlids - dwarf are a pairing to watch.
- Bala Shark Bala Shark is a risk to Zebra Danio: danios / whiteclouds / medakas and sharks are a pairing to watch.
- Bolivian Ram Zebra Danio and Bolivian Ram are an uneasy mix: danios / whiteclouds / medakas and sth american cichlids - dwarf are a pairing to watch.
- Cockatoo Cichlid Zebra Danio and Cockatoo Cichlid are an uneasy mix: danios / whiteclouds / medakas and sth american cichlids - dwarf are a pairing to watch.
No conflict is recorded with the other 81 species in the database, so nothing to flag. 2 species are not covered at all, so they could not be judged either way.