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

Quick 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 in 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. (You can read the Seymour Fish HOB filter reviews 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 the fish seem to 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.

zebra daniosBreeding

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 (I personally recommend New Life Spectrum Small Fry Starter Formula or Hikari First Bites).While it takes a bit more effort and planning, most aquarists prefer to use newly hatched brine shrimp. You can find a brine shrimp hatchery at Amazon.com here.

Comments

  1. cora says

    Thanks for the info.I have danios and when I shut the lights off at night and peek after half and hour or so the only active swimming around are the Zebra Danios, all the other fish are either hiding or sleeping.

  2. bobbi says

    hi there, i have a very round danio and am sure she is carrying eggs, but it’s been awhile now that we have noticed so i’m not exactly positive at least a month or so we noticed her (?) big. for now i have but her in a floating mesh thing to keep her away from other fish. i’m sure not a breeder but would like to take care of any babies that come about…any suggestions would be appreciated…thinking now of putting rocks and marbles in that little mesh thing, i can attach to edge of tank so it doesn’t sink

    • says

      Hello Bobbi,

      Unfortunately those mesh nets generally only work for live-bearer fish, and a zebra danio female won’t release her eggs unless she is kept with males. Zebra danios have courtship behaviour and the male needs to fertilize the eggs as they are released. The eggs inside of the female now won’t be fertilized and she will retain them until she is placed with males in a tank again.

      And zebra danios regularly breed in aquariums – the problem is that they normally eat all of their eggs and fry, which is why in most cases you need a separate aquarium to breed them in, where they can be removed after breeding. I have seen a few zebra danio fry in community tanks over the years, but they only happen in heavily planted tanks that more often than not contain Java moss.

  3. AndreaK says

    Hi. My sun has a few danio’s. Our filter went last night. So My concern. Will the fishes be ok without the filter ? I did try and google. But didn’t find the answer. But came across yours

    • says

      Sorry for the late response, but I’ve been having some issues with the comments. Fish can survive a short while without the filter, but only for about 24 hours max. And that’s assuming the tank is overstocked. I lost a whole tank once after a power outage, and the fish just kept dying one by one. I’m assuming you have a new filter by now, but I like to keep some sponge filters on hand for instances like this. They can never go out.

      • AndreaK says

        Ni no worries. Yes I got a new filter and the fishes are fine. I might look into the sponge filters . Sounds like a good idea

  4. Elisabeth says

    Hello! We love our fish! Have a 10 gallon tank. One red zebra danio, one Glo fish tetra and one small pleco. Noticed a white spot on zebra danio’s back fin today after I siphoned 30% water. He is swimming fine and is happy and active just do not know what to do…. (History: These fish have been in my tank for one year. Had an accident last month with fish when my 2 year old accidentally got a hold of flake food and poured half into the tank). Horrible ordeal . Lost 7 fish. So these three are the lone survivors… PetsMart said to redo the whole tank so I did and these three are last surviving ones). They seem happy. Anyway— I don’t know what the white spot is on Zebra? Could it be stress? They have more room to swim..Plan to get other zebra and tetra soon… Any advice about the one spot? or any other advice would be appreciated. Thanks!

    • says

      That’s horrible about the fish, and I understand the dangers of letting kids near fish food. lol

      What does the white spot look like? Is it more of a fuzz? Or does it look like a speck of salt almost? If it looks like salt, it might be ich, which has to be dealt with. The best way to deal with it, is to start doing daily water changes, making sure to vacuum the substrate daily. The temperature should also be increased to around 80-86, though this should be done slowly, and only a few degrees at a time.

      If this doesn’t deal with it, then you should remove the charcoal from your filter, and buy some medicine to treat the ich. This is very stressful, and will often kill the fish weakened by ich. You also need to be careful, since catfish are very susceptible to this, and you should only use half dosage on them.

      Let me know how it goes.

  5. Linda says

    Hi I have one Zebra Danio and a golden platy in our tank. I don’t know the sexs of these fish but my Zebra looks like it’s pregnant. When we got it it was long and thin and darted constantly around the tank, over the past weeks it’s been getting a bigger belly and less active. Could they have mated? What should I do?

    Linda

    • says

      There could be two things going on here. The first is that it may be bloat, which means your fish is very ill. Otherwise, it may be laden with eggs, but zebra danios don’t get pregnant. They are egg scatterers, so they will never be pregnant in the traditional way.

      If it is bloat, it can be very hard to treat, so hopefully it’s just laden with eggs.

        • says

          I found a picture of a zebra danio with bloat.

          If it looks that bloated, then you’ll want to put it in a hospital tank to separate it from your other fish. Once separated, add some aquarium salt, feed high quality foods (frozen or live work best), and treat with antibiotics that you can pick up at your local fish store.

          If it is bloat, I’ll warn you now that it often doesn’t end well. There have only been a handful of occasions that I’ve won the battle against bloat, and fish often don’t live long afterwards. Hopefully it’s just an egg laden female for you.

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