Zebra Danio Fry Care – How Long Does It Take Them to Grow?

Also known as zebrafish, or even striped danio, the zebra danio is a type of minnow that is native to South Asia and is very popular with hobbyists for home aquariums.

Here we will detail everything that you need to know about zebra danio fry. We will discuss their dietary requirements, the breeding process as well as their journey into adulthood.

What do zebra danio fry eat?

When feeding your zebra danio fry you should treat them the same as any livebearer fry (although they are not). They will need to be fed flakes that have been crushed up into very small pieces. Any form of fish food will be a perfect source of nutrients for your little fry. You must just remember to make the pieces small enough for them to eat!

Zebra danio fry care

Because they are so incredibly tiny when they are born you will need to make sure that you are keeping a close eye on your zebra danio fry. Unfortunately, they can easily become a snack for the other fish in your tank! 

One easy way to do this is to invest in a mesh breeder which can be placed inside the existing tank. This way you can keep them safe from the mouths of other fish without the need to invest in a separate tank. 

However, you will need to make sure that the mesh is very fine as otherwise, your zebra danio fry may swim through the holes! 

How do zebra danio breed?

Zebra danios will typically lay 300-500 eggs along the bottom of your tank. These eggs will then hatch after approximately two days. 

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However, unfortunately, many of the eggs are either eaten by the breeders themselves, by other fish in your tank, or may simply be lost to the water filtration system.

So, in order to save as many fry as possible, you have two options: either remove the eggs from the tank and place them in a separate system (e.g. a mesh container or separate nano tank) or you can remove the fish. 

Basically, you need to separate the eggs from the fish. Thankfully, zebra danios are very avid breeders. So, even if you lose many eggs to fish or the tank itself your zebra danios will still continue to breed frequently.

How many fry do zebra danio have?

Naturally, the number of fry that you will get depends on the number of female zebra danio you have in your tank. One pair of zebra danios will mate together throughout their entire lifetime, so if you are after more eggs make sure that you have enough male-female pairings in your tank. 

One single female zebra danio will typically lay up to 100 eggs during one breeding session. 

How often do danios breed?

Zebra danios are sexually mature in only 10-12 weeks. But for the best egg production, you will need to wait until they are between 7-18 months old. 

When kept in good tank conditions you will find that your zebra danio fish are spawning roughly every 10 days. This is why you may find that you constantly have to keep an eye on your tank to look for zebra danio fry. Although many are lost to hungry fish the breeding pairs more than make up for this in the number of eggs laid.

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How do you tell if zebra danios are breeding?

One easy way to tell if your zebra danios are breeding is to look for what is known as “pairing off”. This is when a male and a female will choose each other to mate for life. 

In a short while, you should either notice that the belly of the female is bloated in appearance. This normally means that she is carrying eggs and will soon lay them along the bottom of the tank ready for them to hatch into little zebra danio fry!

You may also already have the eggs laying along the base of the tank. In this instance, you should take the necessary precautions to protect the fry by separating the eggs from the fish. This way you can ensure that you will manage to save the maximum number of fry possible. 

How long does it take for a zebra danio fry to grow?

As well as reaching sexual maturity by 10-12 weeks, zebra danio fry will usually reach 75-80% of their adult size by this time. 

If you are keeping your fish in a tank with the correct conditions and a good and constant source of food then you can see them reach their maximum size within another 6-12 weeks. By this point, they will be fully grown.

What to do if my zebra danio fish are chasing each other?

Although there is no precise reason why your zebra danio fish may be chasing each other, there are a few options that may affect their breeding process.

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Fish chasing each other can be a form of aggressive behavior. If you have too many males compared to the number of females in your tank then this may be the cause. The males will fight to breed with the female zebra danios, and as they typically mate for life, this can be a problem causing serious competition between the male zebra danios.

If this is indeed the problem then it is simply rectified. You will need to purchase and add more female zebra danios to your home aquarium. This will even out the male-female balance in the tank and stop the competition for breeding.


Zebra danios are a wonderful addition to your home aquarium but they can be a bit of a handful. If you are looking to breed your pairs then you will need to make sure that you are ready to invest the time and money into doing so.

The rate at which they breed means you will always need to keep a careful eye on your tank. Unfortunately, even with good care most of the eggs, or fry, will be lost, but with care, you can save as many as possible

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