Zebra Danio – The Care, Feeding and Breeding of Zebra Danio Fish

zebra danioQuick Stats

Minimum Tank Size: 5 Gallon (10 Gallon Recommended)
Care Level: Very Easy
Water Conditions: pH 6.5-7.2 and Soft to Medium Hard
Temperature: 65-77 °F (18-25 °C)
Maximum Size: 2.5 inches (6 cm)

The zebra danio (Danio rerio) is one of the most iconic fish in the aquarium hobby, and many people have even owned this interesting fish at some point in their lives.

In addition to their attractive coloring and stripes, the zebra danio has a well founded reputation for being a playful and curious fish and makes an excellent addition to almost any community fish tank.

They were originally found in the streams of India, Pakistan and several bordering countries, but have since spread as an invasive species in several US states. In the wild, they can be found in everything from fast flowing streams,  to stagnant rice fields. But their preferred habitat is usually water with a moderate amount of current.

While many of the original zebra danios in the fish trade were wild-caught, nearly all of the ones available now have been breed in captivity on fish farms. Because of this, they are adapted to a wide variety of water types, and if given enough time to adapt, will thrive in most home aquariums.

Zebra danios stay relatively small in the home aquarium, and most will only grow to around 2 inches (5cm) in length. With that being said, some have been known to reach sizes of 2.5 inches (6cm) and there have been reports of even larger ones. They also tend to be a short-lived fish, and most will only live two to three years in a home aquarium, though it’s not unheard of for some to live as long as four or even five years.

Housing

People who has ever kept zebra danios, will often swear that these fish have a touch of ADHD. They are constantly zooming around their aquarium, and because of this, should be provided with the largest aquarium possible – or at least the largest one that you can fit into your budget.

While they can survive in a 10 gallon (37 litre) aquarium, they tend to only really thrive in larger aquarium. Since they are a schooling fish, they need to be kept in groups of at least five, and five danios can quickly become cramped in a 10 gallon (37 litre) aquarium. Any zebra danios that aren’t kept in a school, will often become stressed and may begin to display aggressive behavior towards other fish in the aquarium. However, once their numbers are brought up so that there are at last five of them, most of the aggressive behavior will disappear.

Zebra danios are not a demanding fish when it comes to filtration and any HOB (hang-on-back) filter or sponge filter will usually suffice. HOB filters are usually the best choice, since they not only provide excellent filtration, but they also keep the danios occupied for hours playing in the filter’s current, or making vain attempts to jump up into the filter discharge.

I would strongly recommend choosing an Aquaclear Power Filter for a zebra danio tank. This filter combines excellent filtration with a durable design, and it will keep your tank sparkling clear for years to come. You can also read the Aquarium Tidings Aquaclear Filter Review here.

It should really come as no surprise, that a fish that enjoys jumping up into the filter outflow, also enjoys trying to jump out of their fish tank. So to avoid any untimely fish deaths, any tanks containing zebra danios should always be covered. Barring a cover, the water level should be lowered to make it more difficult for the fish to jump out.

Feeding

Zebra danios are not what you would call fussy eaters, and will eat nearly anything that you offer them. In the wild they tend to mainly feed on small crustaceans, insects, worms and algae. This diet should be reproduced as closely as possible in the home aquarium, and this can be accomplished through feeding them a high quality flake food, and occasional feedings of live or frozen foods. I personally use New Life Spectrum Small Fish, and my fish love it.

But when it comes to live foods, there are few fish that enjoy regular feedings of live food more than zebra danios. They they will greedily accept wingless fruit flies, blackworms, bloodworms, brine shrimp and daphnia. If you can’t provide live foods, then they can be provided with frozen bloodworms, daphnia, blackworms and brine shrimp.

Long fin zebra danioBreeding

The zebra danio has a reputation as one of the easiest fish to breed in the hobby, and they can be a great way for a beginner to experience breeding fish for the first time.

Like many other fish, zebra danios first have to be conditioned to trigger their mating  behavior. The first step in breeding them should always be to separate the sexes into their own tanks. The females can be identified by their plump bodies and rounded bellies, while the males tend to have more streamlined and narrow bodies.

After the sexes have been placed in separate tanks, they should be fed live food  for at least a week. If live food isn’t available, a high quality frozen food can be substituted. Over the course of a week, the female will begin to plump up visibly, as they begin to swell with eggs.

While the fish are being conditioned, a special breeding tank should be set up. It should be fully cycled, and should only be filled with a few inches of treated water, with river rocks or marbles lining the bottom. The rocks or marbles are integral to the breeding process, since it allows the eggs to fall between them – and out of the reach of the hungry parents.

After the fish have finished being conditioned, they can be introduced into the breeding tank, and spawning will normally occur the next day. After spawning, the females will be noticeably thinner, and if they haven’t spawned after a day, they should be moved back into their separate tanks to begin the process over again.

When it comes to parental care, zebra danios are not exactly the model parents of the fish world. They should be removed immediately from the breeding tank after they have spawned, as they are more than happy to eat every egg that they can find. This is why it’s so important to use the marble setup, since it’s unlikely any eggs will survive without it.

Within 48 hours, the eggs will begin to hatch, and the newborn fry can be fed with infusoria, baby brine shrimp or any of the commercial fry foods.While it takes a bit more effort and planning, most aquarists prefer to use newly hatched brine shrimp.

Comments

  1. Dave bullock says

    I’ve got a zebra danio that’s gone very big around the belly and it’s belly is red like a boil is it I’ll or could she be ready for breeding

    • says

      That sounds like your fish may have dropsy, which can be tough to cure. Zebra danios may become more plump when laden with eggs, but it shouldn’t look like that. If it is dropsy, the best bet is to immediately remove it to a hospital tank, so that it doesn’t spread. The hospital tank should have one teaspoon of aquarium salt per gallon, and the fish should be fed high quality live or frozen foods while treating it with antibiotics. The chances for recovery aren’t great, but sometimes you get lucky.

      To make sure it’s dropsy, you can send me a picture to my e-mail at aquariumtidings@gmail.com. Once I see it, I should be able to confirm that it’s dropsy.

      • Laura says

        My zebra danio looks very thin with an unusual arch on this tail, I’m just worried he might die. I have a 1 gallon glofish tank with a cleaner fish and another glofish. What do you recommend?

        • says

          I would recommend getting a larger tank. It’s almost impossible to keep a 1 gallon tank clean, even if you’re changing the water on a daily basis. This is especially true if you’re cleaner fish is a pleco, since they are pooping machines and absolutely kill small tank water quality. I would recommend at least a 5 gallon, though a 10 gallon would be a much better choice.

          The tank probably has ammonia and nitrites building up in it, which is probably making your danio sick. Once you upgrade to a larger tank, your fish should hopefully start to recover. Make sure to use your current filter on the new tank in conjunction with whatever new filter you pick up, since it will take some time for beneficial bacteria to build up on the new filter.

          If you can’t afford a new tank, I would start doing at least two water changes a week while you save up for a new one. I hope this helps.

  2. Rowena Ravenclaw says

    Hi, I have a long-fin danio whose belly is kind of plump. I’ve checked and I’m fairly sure it’s a male. He’s eating and swimming normally and there are no protruding scales or bumps or anything like that on his body, But I’m worried that he’s sick or something. Please help!

    • says

      Plump generally isn’t an issue if there are no other symptoms of bloat or illness. It is likely either eggs and it’s a female or you might want to try and change up the diet a little bit. I’d try feeding it blanched and shelled peas to begin with.

  3. Destinee Tucker says

    I was told that room temp tap water was fine. Is that ok? I can get drops if needed tho. I can’t afford a filter . How often do you feed them ?

    • says

      Room water temperature is fine, but you absolutely have to get the water conditioner. Chlorine will kill of any of the beneficial bacteria that exists in the tank that help to process waste.

      As for a filter, unless you plan to have a heavily planted tank, you will probably just kill your fish. A filter is absolutely necessary, and many are really quite cheap. A sponge filter is a great filter, and with the airline, filter and air pump, you can usually get one for under 20 dollars.

      Feeding can be done once a day, or twice a day in smaller feedings.

  4. says

    At the bottom of my tank there are little balls. Kinda fuzzy and yellowish. I don’t know if they are eggs or not. My emerald green Cory catfish and my zebra danios have not yet noticed them and I don’t have any type of breeding setup and haven’t conditioned my fish. Is there anyway that these could be eggs? What should I do!??

    • says

      They sound like eggs that have become infested with fungus. Either they were never fertilized, or they just went bad for a variety of reasons. My bet would be that they were from your cory catfish, and not from your zebra danios.

    • says

      Do you have snails at all? It definitely sounds like eggs that have grown fungus though. It’s rare for any eggs to survive that long in a zebra danio tank. They are notorious for eating their own eggs, and while I’ve kept danios from the very beginning, I don’t think I’ve ever seen any eggs in their tank.

  5. Maddy says

    i have three zebra danios in a community 10 gallon tank and two of my zebra danios are really fat. they cant swim that well any more. i am pretty sure the third is a male. i put all three in a intank nursery today and both of the fat ones would rest on the bottom. not laying on their side but perched on their bellies. are they pregnant? or am i doing something wrong

    • says

      They sound ill, and they may possibly have bloat. When a female becomes swollen with eggs, it shouldn’t change its behavior in any majorly noticeable way. Are the bellies very swollen? Are the scales sticking up at all?

      I would immediately start with a large water change on their tank (25% of the water or so). Make sure that the water is treated to remove any chlorine, and then I would try to feed them some high quality frozen foods like bloodworms.

      If the bellies are very swollen, you may want to consider some antibiotics for them, though I should warn you that the recovery rate from bloat is very low.

  6. Cecile says

    Hi :)

    About a month ago I adopted 6 zebra danios off a friend who wasn’t looking after them at all! When I took them home they were pale and didn’t swim around much, I didn’t even think they would survive but they have and they seem much happier! As of recently though, 1 of them (who I think is a female after reading this post) seems to be chasing off all of the other fish away when they go near it, more then usual. I’m not trying to breed them at all, is there a chance that she has or has had babies? If not is this normal behavior? They all Chase each other around sometimes but this one stand out from the rest coz it’s a bit more rougher. Based on your post I THINK I have 5 boys and 1 girl. I’ve never owned fish before, I’m loving them heaps and find myself sitting there and watching them for ages lol I just want to make sure that I’m not doing anything wrong :) they are in a 10 gallon tank with a sponge filter and there is a male fighting fish living with them too :)

    • says

      That’s good that you adopted the fish off your friend and gave them a good home. Once zebra danios become more comfortable in their new home, they will often establish small territories in their tank. They also generally have a pecking order, so chasing is also quite normal for them. It sounds like you’re doing great so far with them.

      Just keep an eye on the fighting fish though. Zebra danios will sometimes nip their fins, and if you start seeing damage, you may need to rehome it.

  7. brandi says

    Hey matthew

    I recently bought a 55 gallon that came with 3 zebra danios in it. They are huge 2.5″ to 3″ and I am not sure of the age. I noticed several small fry inside my tank I was able to remove 7 of them.. 6 look ok. If I was to try and raise them what would be the best way. Right now they are in a betta sized tank at room temp since I wasn’t expecting any new additions. They are lucky as I have an albino rainbow shark, upside down catfish and a black ghost knife in the tank that they managed to escape from. Any advice or tips would really help me.

    • says

      That’s great that you found some fry. You definitely need to move them to a larger tank though. Fry are very sensitive to water conditions, and they won’t do well in a betta tank.

      I would recommend at least a 5 gallon tank, with a sponge filter on it. I would also include lots of fast growing plants like hornwort in the tank, since it won’t be cycled when they enter the tank. Once they’re in the tank, they can be fed crushed up flake food, or any of the small live foods like microworms of baby brine shrimp if you don’t mind putting in the extra work.

      If you can’t set up another tank, I would recommend using a breeding net in your main tank. I’m not the biggest fan of breeding nets, but in this situation it would be far superior to the betta tank. In a tank that small, there’s very little chance that ever a hardy fish like zebra danios will survive.

      I hope this helps.

      p.s As your ghost knife grows, all of your fish will start to disappear.

      • brandi says

        Ok great I actually have an empty 5 gallon and a few extra live plants currently. I will head to the aquarium store for some food for the fry. Right now my ghost knife is smaller then the danios but at what point should I separate them?

        • says

          In my experience they start to become dangerous to other fish when they reach around 4-5 inches in length. For safety sake, I would recommend relocating it at the point. They grow very large though, and an average one can easily reach 12-13 inches in the home aquarium. So it will need a big tank on its own.

  8. Vicki says

    I have 50 or so neon Danios. Apparently one of the adults laid eggs right before we switched tanks. The old tank was not emptied right away, and three days later it was swarming with fry. There were close to one hundred at first. They are now almost two months old. Our biggest tank is 25 gallons. How many will survive in there? What do I feed them now that they are bigger? They have been eating crushed shrimp pellets, but the tank gets nasty fast.

    • says

      They should be fine with what you’re feeding them, though they would appreciate frozen foods now and then. Once they’re a bit larger, you can start feeding them frozen blood worms, daphnia and brine shrimp.

      As for how many will survive, all I can say is that danios are incredibly resilient. They can survive in terrible conditions, which will cause problems for you later down the line. If you keep up with water changes, and the tank doesn’t crash completely, you could end up with most of them alive well into adulthood. However, they will probably be unhealthy, with damage to their gills from ammonia and they will also probably be stunted. I would give a large number of them away so that the ones you keep will remain healthy.

      • Vicki says

        Thank you for the info! We have been trying to give them away, but nobody wants them. I know we can’t sell them, but will a fish store take them off our hands? Otherwise we’ll be searching for a large enough tank so the survivors stay happy and healthy!

        • says

          Most fish stores will either take them for store credit, or will just simply take them off your hands for no money. The caveat is that they have to be at least half an inch (1.5 cm) before most stores will take them. Another great resource are regional fish forums. If you look, most major cities have a fish forum that usually have a for sale section.

          I hope you find a home for them.

      • Vicki says

        Also, what is a good bottom feeder for them? I’m afraid our Cory fish will eat them, and the snail doesn’t eat enough.

        • says

          The majority of fish will eat zebra danio fry if given the chance. And what do you want the bottom feeder for? If you’re looking for a clean up crew, I use Malaysian trumpet snails in most of my aquariums. They’re relatively attractive, and consume all the uneaten food and a fair bit of algae.

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