Zebra Danio

Zebrafish, Striped Danio, Zebra Fish

Family: Cyprinidae Picture of a school of Zebra Danios, Danio rerio, ZebrafishDanio rerioPhoto © Animal-World: Courtesy David Brough
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I bought a new tank(Dimension:-L24"X B12"X H14") Kept 8 guppies , 15 neon tetras and 4 Zebra Danios, total fishes were 27, i made a water change on the very next... (more)  zoeb

The Zebra Danio is a popular aquarium fish favored for its charm and grace as well as its hardiness!

The Zebra Danio Danio rerio (previously Brachydanio rerio) is a lively little schooling fish that only reaches about 2 1/4 inches (6 cm) in the aquarium. It's easy to recognize with its attractively striped, black and white "zebra" patterned body. This is one of the first types of tropical fish to ever be kept in the aquarium, and it is still enormously popular. This pretty, inexpensive fish is a great choice for both beginning and advanced aquarists. Other common names it is known by are Zebrafish, Striped Danio, and Zebra Fish.

Dozens of variations of this Danio are selectively bred today, with a variety to suit every taste. Some of the best known include the Longfin Zebra Danio and color morphs like the Golden Zebra Danio, Albino Zebra Danio, Longfin Blue Danio, and Sandy Zebrafish. Other well known varieties are the Leopard Danio and Longfin Leopard Danio, both of which have spots instead of stripes. There is also a variety called the Hybrid Danio, for those who just can’t choose between spots and stripes, which has a combination with both. A recently introduced variety is a Zebrafish (Danio rerio) genome known as the “Glo-fish.” This is a genetically modified little fish available in beautiful fluorescent colors of bright red, green, orange-yellow, blue, and purple.

These hardy and attractive Cyprinids are ideal for beginners. They are prolific breeders and the easiest type of egg layers to breed. A schooling fish, they should be kept in a small group of at least 3 individuals, though 5 or more is best. Because they are so small, a school is suited to a smaller aquarium of at least 20 gallons. They can be housed with most any community fish. Just make sure that the danio will not be eaten and that the other fish aren’t startled by swift movement.

Zebrafish are very durable and can withstand an impressive range of water temperature and conditions. They will generally do just fine without a water heater as they are comfortable at temperatures down to the low 60s (F). But even though they are not finicky about water conditions, it's best to not keep your aquarium at any extreme. Don’t be surprised if the school spends a lot of time in the water flow of the filters or pumps as a swift-moving environment is what they are accustomed to in nature.

Take care that neither specimens of this fish nor fertilized eggs be released into the environment. Zebrafish are tropical and can't survive in areas of extreme weather conditions. They have been used for mosquito control and have invasively populated some environments.

For Information on keeping freshwater fish, see:
Freshwater Aquarium Guide: Aquarium Setup and Care

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Cypriniformes
  • Family: Cyprinidae
  • Genus: Danio
  • Species: rerio
Zebra Danio - Quick Aquarium Care
  • Aquarist Experience Level: Beginner
  • Size of fish - inches: 2.4 inches (5.99 cm)
  • Minimum Tank Size: 10 gal (38 L)
  • Temperament: Peaceful
  • Aquarium Hardiness: Very Hardy
  • Temperature: 64.0 to 75.0° F (17.8 to 23.9° C)
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Habitat: Distribution / Background

The Zebra Danio Danio rerio (previously Brachydanio rerio) was described by Hamilton in 1822. They are found in Asia from Pakistan to India and as far as Myanmar. They occur in the Kosi River in Uttar Pradesh, northern India, and in smaller numbers in Nepal, Bhutan, and Bangladesh. This species is listed on the IUCN Red List as Least Concern (LC) as they are widespread throughout their range with no major identified threats. Other common names this species is known by include Zebrafish, Striped Danio, and Zebra Fish.

There are dozens of variations of this Danio, with the Albino Zebra Danio being a naturally occuring color morph. Many varieties and color morphs, including the Albino, Longfin, Golden, Sandy, and Leapard Zebra Danios, are bred in captivity today. A more recently introduced variety is a Zebrafish (Danio rerio) genome known as the “Glo-fish,” a genetically modified little fish developed by scientists. They added a natural fluorescent gene to the fish, which will absorb light and then re-emit it, in the hopes of being able to detect contaminates in waterways. Though Glo-fish are perhaps the most controversial little fish in the hobby, at present there are no known adverse effects to the fish or to the environment. They became commercially available in the United States in late 2003 and are available in beautiful fluorescent colors of bright red, green, orange-yellow, blue, and purple.

Zebrafish inhabit the lower reaches of streams, canals, ditches, and ponds. Their habitat varies greatly depending on the time of year. Adults are found in large numbers in seasonal pools and rice paddies during the wet season where they spawn and feed. These are still waters with a substrate that is silty and heavily vegetated. The adults then return to the faster moving waters of rivers and streams for the dry season, where the substrate is normally rocky and shaded. The young will stay in the still waters until maturity, then they too migrate to the rivers. In the wild, these fish are considered micropredators and feed on worms, small aquatic crustaceans, insects, and insect larvae.

  • Scientific Name: Danio rerio
  • Social Grouping: Groups
  • IUCN Red List: LC - Least Concern


The Zebra Danio has a slender, compressed body and a barbel at the end of each lip. These small fish reach lengths of only up to about 2 1/4 inches (7 cm) in the aquarium, though they can get slightly larger in a pond. They are thought to be primarily an annual species in the wild, but in captivity they can have a lifespan of 3 to 4 years. Some have lived up to 5 1/2 years with proper care.

The body of this species has a very pale yellow to white background marked with five steel-blue horizontal stripes that fade into the fins and extend onto the tail fin.

Some varieties and color morphs of this fish include:

  • Long finned Zebra Danio
    This is merely the Zebra Danio selectively bred to have extended fins. It has nearly exceeded the traditional variety in popularity.
  • Leopard Danio & Longfin Leopard Danio
    Although sometimes separated as different species, the Leopard Danio is actually a captive-bred color morph first developed by a Czech scientist. Instead of stripes, this sides of this fish are adorned with steel blue spots. They will readily school with regular Zebra Danios, and they can even breed together. The longfin variety has been bred to have an extended tail and fins.
  • Hybrid Danio
    The Hybrid Danio is a selectively bred color morph for those who just can’t choose between spots and stripes. Its sides are spotted about halfway down the body, at which point the spots condense into stripes. Hybrid danios are fairly new to the hobby. They can breed with either the Leopard or Zebra Danio, but offspring won’t stay true to the parent’s coloration.
  • Golden Zebra Danio
    This gold color morph of the Zebra Danio has had the blue stripes bred out. This fish can sometimes be confused with the Pearl Danio Danio albolineatus, which is an entirely different species.
  • Albino Zebra Danio
    This color morph is a naturally occurring phenomenon. As the name suggests, this variation has no pigments. Do not confuse it with the Pearl Danio.
  • “Glo-fish”
    This little fish is a recently introduced Zebrafish (Danio rerio) genome. It has been genetically modified to sport fluorescent red, green, orange-yellow, blue and purple colorations. They also glow in the dark or under a black light. Their care does not vary from the natural Zebra Danio.
    • Size of fish - inches: 2.4 inches (5.99 cm)
    • Lifespan: 4 years - They have an average lifespan of about 3 1/2 years, though some have lived up to 5 1/2 years with proper care.

    Fish Keeping Difficulty

    The Zebra Danio is a great choice for beginning aquarists, and they are great companions in a community aquarium. These fish will eat just about anything that is offered as long as it floats at the surface where they can readily consume it. They tolerate water condition changes without too many issues and can even be kept without a heater.

    • Aquarium Hardiness: Very Hardy
    • Aquarist Experience Level: Beginner

    Foods and Feeding

    These fish are omnivorous, feeding mostly on a variety of worms, small crustaceans, and insect larvae in the wild. In the aquarium, they will eat most any prepared or live aquarium food, though it does need to float at the surface.. They enjoy chasing after tubifex worms, either living or freeze-dried. These fish will do best when offered food several times a day, but offer what they can eat in 3 minutes or less at each feeding. If you feed only once per day, provide what they can eat in about 5 minutes.

    • Diet Type: Omnivore
    • Flake Food: Yes
    • Tablet / Pellet: Yes
    • Live foods (fishes, shrimps, worms): Some of Diet
    • Vegetable Food: Some of Diet
    • Meaty Food: Some of Diet
    • Feeding Frequency: Several feedings per day - Offer only what they can consume in 3 minutes or less with multiple feedings per day.

    Aquarium Care

    These fish are easy to care for provided their water is kept clean. Aquariums are closed systems, and regardless of size, all need some maintenance. Over time, decomposing organic matter, nitrates, and phosphate build up, and water hardness increases due to evaporation. Replace 25 to 50% of the tank water at least once a month. If the tank is densely stocked, 20 to 25% should be replaced weekly or every other week.

    • Water Changes: Monthly - If the tank is densely stocked, water changes should be done every other week.

    Aquarium Setup

    The Zebra Danio is a schooling species that will spend most of its time in the top and middle regions of the aquarium, particularly if there is open water or water current. This fish is fairly hardy and will adapt to most aquarium conditions. The waters they inhabit in the wild are acidic, but the stock now available in the hobby is many generations past this. Though a school of danios can be kept in a smaller aquarium, they will do best in about a 20-gallon size. Provide good filtration and keep the tank covered as these fish may jump.

    These fish are most effectively displayed in tanks that simulate their natural habitat and bring out their colors. Use a dark, fine gravel or sand substrate, and provide a variety of plants to make them feel safe. Some good selections include Water Wisteria, Hornwort, and Java Moss. As with most Cyprinid fish, they are most at home in well-planted aquariums, but as these fish are extremely active swimmers, they also need some open areas for swimming.

    • Minimum Tank Size: 10 gal (38 L)
    • Suitable for Nano Tank: Yes
    • Substrate Type: Any
    • Lighting Needs: Moderate - normal lighting
    • Temperature: 64.0 to 75.0° F (17.8 to 23.9° C)
    • Range ph: 6.0-8.0
    • Hardness Range: 2 - 20 dGH
    • Brackish: No
    • Water Movement: Weak
    • Water Region: All - They will spend most of the time in the top and middle regions of the aquarium, particularly if there is open water or some current.

    Social Behaviors

    The lively Zebra Danio makes a good community fish. It will get along with its own kind and most other species. They are best kept in a school of 5 or more of their own kind. Groups of this fish can be hierarchal, and a pecking order may emerge in the school, but nothing will come of it. Select tankmates that are similar in temperament. You want tankmates that can keep up with the fast-paced lifestyle of this Danio. Mellower fish that need a less hectic environment can become stressed.

    • Temperament: Peaceful - They are good community fish with other fast-moving tankmates.
    • Compatible with:
      • Same species - conspecifics: Yes - They are best kept in groups of 5 or more.
      • Peaceful fish (): Safe - Tankmates need to be able to tolerate the lively nature of this species.
      • Semi-Aggressive (): Monitor
      • Aggressive (): Threat
      • Large Semi-Aggressive (): Threat
      • Large Aggressive, Predatory (): Threat
      • Slow Swimmers & Eaters (): Monitor - Large groups of Zebra Danios may make these fish nervous because of their activity level.
      • Shrimps, Crabs, Snails: Safe - not aggressive
      • Plants: Safe

    Sex: Sexual differences

    The females are generally more colorful while the males are more streamlined and slim.

    Breeding / Reproduction

    The Zebra Danios are very easy to breed, and it may even occur on accident. Two fish will form a breeding pair, which they often keep for life. If you wish to retain the young, the breeding tank should be empty except for a 2-inch layer of large glass marbles, 1/2 to 1 inch in diameter. Add the female to the tank, and let her settle for about a day before adding the male. When they are both in the tank, adding a few cups of cold water will cause the courtship to begin.

    If conditions are favorable, the female will release her eggs in open water, and the male will fertilize. The eggs will then sink to the bottom and fall through the marbles, out of their parents' reach. The fry will emerge from the marbles after about 7 days. At that time or before, parents should either be removed or kept constantly well-fed. See the description of breeding techniques in Breeding Freshwater Fish: Barbs. Also, see Fish Food for Fry for information about types of foods for raising the young.

    • Ease of Breeding: Easy

    Fish Diseases

    Zebra Danios are extremely hardy, so disease is not usually a problem in a well-maintained aquarium. They are primarily susceptible to Ich if good water quality is not provided. Anything you add to your tank can also bring disease. Not only other fish but plants, substrate, and decorations can harbor bacteria. Take great care and make sure to properly clean or quarantine anything that you add to an established tank so as not to upset the balance.

    These fish are very resilient, but knowing the signs of illness, and catching and treating them early makes a huge difference. An outbreak of disease can often be limited to just one or a few fishes if dealt with at an early stage. The best way to proactively prevent disease is to give your fish the proper environment and a well-balanced diet. The more closely their environment resembles their natural habitat, the less stress the fish will have, making them healthier and happier. A stressed fish is more likely to acquire disease. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.


    The Zebra Danio is inexpensive and readily available in stores and online.


    Author: Clarice Brough CFS, Barbara Roth
    Lastest Animal Stories on Zebra Danio

    zoeb - 2019-06-05
    I bought a new tank(Dimension:-L24"X B12"X H14") Kept 8 guppies , 15 neon tetras and 4 Zebra Danios, total fishes were 27, i made a water change on the very next day by adding water to bucket and putting antichlorine and later after 30 min, putting the water in the tank. the 3rd day was a death day , 1 guppy died and then till today ie:- the 7 day , im just left with 8 fishes. initially i was suspecting my filter , then the water, now im left with no guppies, 2 zebra danios and 6 neon tetras.

    Ive been investigating what i did wrong, ive seen that 1 zebra danios keeps on chasing other neons and even nipping.

    i wonder if water was the problem or zebra danios was the reason or both..

    do zebra danios even attack guppies

    the chasing zebra seems twice the size of any other fish in the tank.

    please help

    • Dave - 2019-06-05
      More than likely the aquarium was not cycled. How long has it been set up? you should run the filters for about 6 weeks with only a couple of hardy fish in order for the bio-filter to establish itself.
    • Robert - 2019-09-15
      Zebras are very hardy and top surface fish can even be kept in cold water they always fast moving and i guess they need some good swim space - they should be in a shoal - neon's are more middle of the tank and also shoal fish - they need accurate temperature and the water needs to be right - changing water just a day after you introduced new fish is no good - means you changed them twice in short time and that can be hard for any fish to adjust. i never had Zebras doing any harm to any other fish. still must have nice 'furniture' in the tank so any fish got a chance to hide away from each other
    Doug - 2009-03-13
    Don't know why it's not on here but zebra danios will kill neon tetras. I have had fish for 15yrs & every time I put zebras in my tank they kill my neons. It's happened 6 differnt times. Has anyone else had this problem?

    • chad - 2010-02-19
      I have 4 glofish and one zebra danio. I recently added one glow light tetra and it was very calm. I thought these fish would get along, but now two days after I buy the tetra; I come home and my glofish had killed my tetra.
    • Gord - 2010-04-21
      I have had the same experience. I have introduced neons to a community of danios and bloodfins twice, and the neons disappeared within a two or three weeks. I would advise against trying to house them together.
    • caity - 2010-05-24
      eeee really I have not got them yet but I am getting soon. Do the zebra danios eat the neon tetras I have them :(
    • lps - 2010-07-25
      I'm having that same exact problem! How do I stop it from happening?!
    • w. r - 2011-01-16
      Yes, I first started my new tank with 1 zebra danio and yesterday I bought a neon tetra soonest I put it in the tank the zebra started to chase him, I return it to the store and came with another zebra and the biggest one started to chase the small zebra, are this fish crazy or what?, I think that they might need xanax.
    • Alden Finnie - 2011-09-10
      Wow, That's weird. I have 18 neon Tetras and 6 Zebra Danios. They get along fine and it's been 8 months. The Danios only seem to harmlessly bother each other. Chasing each other in a big circle around a rock.
      Thanks though. I'll keep an eye on them.
    • carla - 2011-09-15
      Hi I would just like to say that I disagree with you, as I have danios and tetra living together, and have had no problems. They are highly compatable. Mine have been living together for over 6 months and are very happy together,
    • Anonymous - 2011-10-18
      We have had 2 danios in with our tetras for over a year and there has been no problem. The male danio chases the female and the tetra very aggressively, but that is all.
    • Kim - 2011-12-01
      I have 8 big zebra danios and I had 24 neon tetras, I now have 7 neons left! I had never thought of this before, but they are the only fish big enough to eat the neons, so it has to be them! Damn it they have decimated the neons, going to have to sell the danios I think.
    • Tanya Altice - 2012-02-20
      When I had my tank I learned that a) you have to provide schools for each fish danios like at least 5 like fish in the tank. Neons like even more than that. b) generally you buy neons very small! and and small new fish don't do well with established bigger fish. So I would say get a small 5gal tank and set it up for a school of about 8 neons and let them get bigger than what you normaly buy them. Then put them in your tank with the others and give your danios some friends to play with so they will leave the others alone. Also neons aren't very hardy. I have had several trips around and around with neons where they simply die within a week of buying them. So be prepared to spend some time building a good school of neons.
    • Alonzo T. Fells II - 2012-04-15
      I have to disagree with that. I had group of 5 zerbra danios and they never had bother the neon or the rest of mine tetras. Yea, a little bit of fish nipping but they play tag with mine rams lol
    • Maeve - 2012-05-20
      Oh, really? I didn't know that. Do danios get along with goldfish?
    • Jeremy Roche - 2012-06-26
      Zebras Danios are famous for stressing and harrassing other fish.  They are small but they are very fast swimming and in groups this can be taken as aggressive and make others stressed.  Neons are easily stressed.
    • aiden - 2012-06-26
      i just put 10 neons in my tank with my 2 zebra danios, (there were 3 but the others bullied the smallest until it died) 3 hours later the first neon is dead and they're trying hard to single off another!
    • Anonymous - 2014-06-06
      I have zebra and leopard ones they killed my goldfish 😒
    • moonisha - 2015-11-11
      my big fish chases the small one
    • Nikki - 2015-11-14
      These guys have killed and eaten 5 mollies, 4 male guppies, 5 neons (since last weekend), 2 bottom feeders, a redtail fin shark (since last weekend). All since Christmas. Only things that have made it are 5 red tetras that the neons tried to stay with because the Zebras won't go near them, and my son's big gold fish he won at a carnival. I'm getting ready to put them in a tank of their own so I can get other fish. Oh we also have a small catfish that stays hidden until feeding time.
    • Skyler Goument - 2015-11-14
      Yeah I disagree when I first set my tank up I got 5 neon tetras and 2 danios and they have got along and lived well for almost 2 years now. Recently I aded a few more smalll neons and some of the others had died and the danios are treating them pretty well. Just make sure you have less danios then neons :)
    • Skyler Goument - 2015-11-14
      Niki, are you sure it was the danios that killed them and not a disease or a tank problem? As danios are very hardy they wouldnt have been affected by it? 

    • Steve - 2017-04-27
      I put four zebras in my 18 gallon aquarium to cycle it. Then, I added six neon tetras, six panda corydoras, three Virginia corydoras, six galaxy rasboras and four male guppies - not all at once, of course.

      There is no fighting or nipping. Everyone gets on great. Four of the rasboras disappeared quickly, but the other two are fine. (They are very tiny fishes.) I don't know what happened to the rasboras.

      During the last two or three weeks, one neon and one panda vanished. I don't know what happened. Maybe they just died of natural causes. No carcase was ever seen. I replaced the neon and the panda yesterday.

      I have seen nothing to suggest that the zebras are attacking the neons or any of the other fishes.
    • Ren - 2018-06-22
      The reason is because neons are so small
      that it looked like food to the zebras. I
      recommend you get bigger fish.
    Jack - 2016-07-31
    I have a spotted danio and I went on holiday I got back and it had a hole on the back left of its tummy. Also it was breathing heavily. Any ideas what caused it?

    Mishel - 2016-01-18
    I have had Zebras for a while and never suspected them to be aggressive until I upgraded to a larger tank. I added 7 neon tetras and my zebras harassed them to the point where 6 died off. Some tetras were half eaten. They even tore up 1 male guppy I had. I just finished feeding them and the guppy was fine until I checked back on it 3 hours later and the back fin was torn into shreds along with marks all over its body.

    • shivam sachan - 2016-06-30
      Hi mishel, sorry to hear about your neon tetras.. i have 10 danios and along with them i have 20 guppies and 10 neon tetras and lots of other fishes to.
      But i had no problems with zebras and neon tetras they are good and they love each others company. well recently some of my neon tetras died but it was my newly bought killi fish who killed them.. i would like to hear did you had any other fish in tank when your tetras died?