Skip to Content

14 Reasons Why Your Guppy Fry Died In Your Tank!

After publishing our article going over why and adult guppy may die in your tank, we have noticed more and more people reaching out and asking why the guppy fry in their tank died.

Guppy fry can be extremely delicate and fragile, especially if you are not used to breeding your guppies so survival rates can be low for the species, even if your tank setup is perfect.

Still, there are a number of things that you are able to try and prevent occring in your tank in the future to try and increase the potential lifespan of your pet guppies.

This is why we have decided to publish this article, to try and go over some of the most common mistakes that we see people within the fish keeping community make time and time again that can result in your guppy fry dying.

They Were Eaten!

As we covered in our article going over the tank makes that eat guppies, the small size of guppy fry make them an ideal snack for a hungry fish. Unfortinatley for guppy fry, this also includes their own parents who will commonly turn around and eat them!

This is why we recommend that you seperate your fry from the rest of the fish in the tank as soon as they are born by using a breeding box if possible. Not only will this protect them from being eaten, but it will also give them time to grow a little bit before being reintroduced into the main tank.

Ideally, if you are intentionally breeding your guppies, you will be putting the pregnant females into a cheap, 10 gallon breeding tank. As soon as the female guppies have given birth to their fry, you remove the mothers so the guppy fry as in a safe environment free from predators.

The Guppy Fry Had Bad Genetics!

Unfortinatley, due to their popularity, guppies have been inbred for decades often resulting in very bad genetics in the fish. This is why you will sometimes see fish that have extremely deformed tails or bodies.

The inbreeding has also resulted in many guppy fry being born with genetic defects that can be passed down from generation to generation.

These defects often result in the death of the fry soon after they are born or shortly thereafter. In some cases, the fry may live for a few weeks or months but will eventually succumb to their injuries.

There is no real way to know if your guppy fry have bad genetics until they are born and start to die off. However, if you notice that a high percentage of your fry are dying soon after birth, it is likely due to bad genetics.

As we covered in our guide to mutt guppies, although many guppy breeders will try to keep mutt guppies out of their breeding lines, this actually prevents this genetic issues in mutt guppies often making them a very hardy guppy that is more forgiving for beginners that can produce healthy guppy fry with ease.

More and more people are trying to crossbreed their guppies with mollies to create the muppy hybrid fish too. Although this is possible, we would never recommend that beginners try to cross breed their guppies as the fry are often weak and have issues with their genetics.

Complications During The Birthing Process!

Guppies are livebearers, meaning that they will give birth to live fry instead of eggs. This is why you will often see people say that their female guppy “gave birth.”

The process of giving birth can be very difficult for the female guppy and if there are any complications, it can result in the death of fry and potentially the mother. This is surprisingly common and we have an article going over how to help a pregnant guppy not giving birth that you may find helpful.

The Fish Tank Was Too Highly Stocked!

One of the most common reasons why fry die soon after birth is because the fish tank that they were born in was too highly stocked. This often happens when people don’t realize how fast guppies can reproduce and end up with too many fish in their tank.

This results in poor water quality which can lead to all sorts of problems such as disease, stress, and death. This is why it is so important to keep up with your water changes and make sure that your tank is not too highly stocked.

If you have too many fish in your tank, the best thing that you can do is to remove some of the fish and either put them in another tank or give them away. A heavily stocked tank also increases the number of potential predators wanting to eat your guppy fry too.

We have an article going over what to do if you have too many guppies in your tank that you may find helpful if you are looking to keep breeding your guppies.

The Guppy Fry Starved To Death!

Another common reason why fry die soon after birth is because they starve to death. This often happens because the fry are too small to compete with the other fish in the tank for food.

Even more common than this is that the guppy fry are being offered food that they are not actually able to eat. Guppy fry are tiny for their first week or two and their small jaws can’t offer many foods that are usually given to guppies.

You will be surprised that this is one of the leading causes of guppy fry dying but something as simple as a fry fish food starter product can be enough to prevent this from happening and ensure your guppy fry have plenty of food.

Not Enough Hiding Spots In The Tank!

Another common reason why fry die soon after birth is because there are not enough hiding spots in the tank. This can be due to a number of different factors such as not having enough plants, not having enough rocks, or even not having enough caves.

If the fry do not have enough places to hide then they can get stressed and sick. Thankfully, something as simple as fish fry hides or breeding grass can be enough to prevent this and make sure that your guppy fry live.

Low Quality Water!

As we briefly mentioned earlier, one of the most common reasons why guppy fry die soon after birth is because of poor water quality. This can be due to a number of different factors but is often the result of overfeeding or not doing enough water changes.

Water quality is so important for all fish, especially fry that are very sensitive to changes in their environment. If the water quality in your tank is poor, it can lead to all sorts of problems such as disease, stress, and death.

This is why it is so important to do regular water changes and keep up with your maintenance.

Tank Water Temperature Was Not Correct!

Another common reason why fry die soon after birth is because the water temperature in their tank was not correct. This is often due to people not having a heater in their tank or not having it set to the correct temperature.

Guppy fry are very sensitive to changes in temperature and even a few degrees can be enough to cause problems. If the water is too cold, it can lead to the fry getting sick or even dying.

If the water is too warm, it can also cause problems such as stressing out the fry and making them more susceptible to disease. The ideal temperature for guppy fry is around 80°F (26°C) and should offer the highest possible survival rates.

Your Guppy Fry Were Stressed And Anxious!

Another common reason why fry die soon after birth is because they were stressed and anxious. This can be due to a number of different factors such as being in a heavily stocked tank, poor water quality, or even the wrong water temperature.

Stress and anxiety can lead to all sorts of problems such as disease, death, and even stunted growth. This is why it is so important to try and reduce the amount of stress in your fry’s environment.

One of the best ways to do this is by using a breeding trap or breeding net. This will allow the fry to have their own space away from the other fish in the tank and help reduce their stress levels.

A Lack Of Oxygen In The Tank Water!

One of the most common reasons why fry die soon after birth is because there was a lack of oxygen in the tank water. This can be due to a number of different factors such as overstocking, poor water quality, or even not having enough aeration in the tank.

If the water in your tank is low on oxygen, it can lead to the fry getting stressed, sick, and even dying. This is why it is so important to make sure the tank is properly aerated and that you are not overstocking.

The Water Flow Of The Tank Was Wrong!

Another common reason why guppy fry die soon after birth is because the water flow of the tank was wrong. This is often due to people not having enough filtration or not having the right type of filter for their fry tank.

If the water flow in your tank is too strong, it can stress out the fry and make them more susceptible to disease. If the water flow is too weak, it can also lead to problems such as a lack of oxygenation and poor water quality.

It is important to make sure the water flow in your fry tank is just right so that the fry are not stressed and the water quality is good. A low water flow is usually the highest we would recommend for guppy fry but many people will have no water flow at all in their breeding tank.

Ammonial Levels In The Tank Got Too High!

One of the most common reasons why fry die soon after birth is because the ammonium levels in the tank got too high. This can be due to a number of different factors such as overfeeding, not doing enough water changes, or even having too many fish in the tank.

If the ammonium levels in your tank get too high, it can lead to the fry getting stressed, sick, and even dying. This is why it is so important to do regular water changes and keep up with your maintenance.

Your Tank Has Problems With Parasites!

Another common reason why fry die soon after birth is because there are problems with parasites in the tank. This can be due to a number of different factors such as poor water quality, not cleaning the tank often enough, or even bringing parasites into the tank on new fish.

If there are parasites in your fry tank then they can be difficult to treat due to most of the better parasite treatments being too strong to use with fry in the tank. Due to this, you may be forced to just leave the fry with the parasites and hope for the best, especially if the fry are less than a week old as they are too weak for most parasite treatments.

There Was A Spike In Nitrates And Nitrites!

One of the most common reasons why fry die soon after birth is because there was a spike in nitrates and nitrites. This can be due to a number of different factors such as overfeeding, not doing enough water changes, or even having too many fish in the tank.

If there is a spike in nitrates and nitrites, it can lead to the fry getting stressed, sick, and even dying. This is why it is so important to do regular water changes and keep up with your maintenance.