Why did my Guppy Fish Die After Giving Birth?

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Guppy fish may suddenly die after giving birth or even while giving birth. This can happen for various reasons that I’m going to cover in this article.

Some of these reasons are preventable (e.g. by reducing stress, keeping water conditions at ideal parameters, etc.), others may not be preventable.

The labor of your guppy fish should go smoothly, but sometimes due to external factors or some pre-existing conditions problems may arise that will cause the death of the pregnant female guppy.

So, why do guppy fish die after giving birth and what can you do to prevent this from happening?

Here are the most common reasons why your female guppy fish may die just after releasing the fry:

Complications During Labor

Guppy fish can release a lot of fry when giving birth and the process may take a couple of hours, even a day or two in some instances.

Female guppies usually reach reproductive maturity at three months of age, sometimes even sooner if water conditions are favorable for breeding. But how can you tell if she’s pregnant or not?

One indicator that a female guppy is pregnant is that her gravid spot – a dark spot under the tail, at the back of the abdomen – becomes enlarged and darker in color.

Another indicator – which becomes more apparent as she advances in her pregnancy – is an enlarged abdomen. The female guppy will grow larger and bulkier around her belly.

The gestation period can last anywhere between 21 days to 30 days or even longer if water conditions are not ideal for her. E.g. the water is too cold or if she feels in danger.

Pregnant guppy females prefer warmer water in the 72-79 degrees Fahrenheit range. In colder water, the pregnancy will last longer.

If everything is in order in your aquarium, female guppy fish have no issues releasing fry, however, difficult labors when the female guppy has trouble expelling the fry do occur.

There are various reasons why this happens:

  • Fry get stuck in the birth canal due to a deformity or an overdue pregnancy (stress can prevent female guppy fish to release the fry);
  • The female becomes stressed out because she has been moved or handled in a way to induce stress (this can lead to miscarriage or spontaneous abortion);
  • Labor complications due to bad water conditions.

If you see your guppy fish struggling to give birth or the labor process drags on too long, there are a few things you can do to ease the process of labor:

  • Try turning off the lights in the aquarium and make sure to provide a comfortable hiding space for your fish;
  • Some aquarists report having some success when adding a bit of aquarium salt to the water.

Above all, I suggest that you make sure the water is clean and there are plenty of plants or decorations that would allow the female guppy fish to hide.

It’s also better for her to be kept in her own breeding tank and not in a mixed aquarium to prevent her from getting bullied or stressed out by other fish.

Plus, other fish will eat the fry, which you presumably want to avoid if you’re breeding them. A separate breeding tank will also make it easier to prevent the fry from getting eaten since you can remove the female as soon as she gives birth.

Too High Stress (Related to Pregnancy)

When female guppy fish become pregnant, they’re more susceptible of getting stressed out. It’s important for them not to feel in danger. Therefore, stress is a major pregnancy risk factor in guppies.

When you buy an already pregnant guppy from the pet store, the simple act of moving her to a new aquarium where water parameters are different from the tank of origin exacerbates any stress she may be experiencing.

Ideally, pregnant female guppy fish should be left undisturbed and should be made to feel as comfortable as possible.

When moving her to a breeding tank, you should match the water parameters of the original tank otherwise you risk shocking the fish because of differing water parameters.

You should also provide plants for cover and avoid keeping her with other fish that might disturb her.

Signs of stress include erratic swimming in the tank, refusal to eat, sitting at the bottom of the tank (although this can also be a sign that she’s preparing to spawn), fading colors.

Technically, any major behavioral change you may notice can be a sign of stress, so keep an eye on your female guppy to notice any signs that may be cause for alarm.

You should also make sure to feed pregnant guppy fish with a nutritious diet because the pregnancy itself, and then later the labor, can be very exhausting considering that guppies can drop anywhere between two to 200 fry with every pregnancy.

Female Guppy Was Already Sick

Sometimes when your female guppy fish dies after releasing the fry, isn’t necessarily caused by the pregnancy itself or stress factors.

If you got her from a pet store, it’s possible that she’d been sick before you even took her home.

It’s also possible that she could have become sick while in your care because of various factors like improper water conditions, unstable temperatures, a parasitic infection or a bacterial infection.

Depending on the particular disease, you may be able to prevent her from dying if you catch the disease in its early stages.

You will also need to apply treatment, if possible, to the fry as many guppy fish diseases can be passed on to fry as well.

Therefore, I recommend that you familiarize yourself with the symptoms of the most common guppy fish diseases, so you can spot the signs of a disease early and offer adequate treatment.

Inadequate Water Parameters

Bad water conditions can be a significant stress factor for pregnant guppy fish. But so can inadequate water parameters, especially when moving female guppies to a new place just as they’re about to give birth.

As I mentioned in one of the previous points of this article, I always match the exact water conditions of the tank of origin when setting up a breeding tank.

This will help pregnant guppy fish feel more at ease. I also transfer her as quickly as possible and with the least amount of disturbance.

If water parameters are bad or inadequate, you increase the chances of something going wrong during labor because of the high stress your guppy fish are experiencing.

Stress due to Keeping Guppy Female in Breeding Box

Breeding boxes can be useful when you have a larger tank and you don’t want to set up a separate tank, or you simply don’t have the time to properly set it up.

You can set up a breeding box – a hang-on type – even if you have a small aquarium, but you’ll need extra equipment to help the water circulate through the breeding box.

Either way, while useful, breeding boxes can be stressful for a pregnant guppy fish, especially if it’s too small or there isn’t any place to hide.

Ideally, you shouldn’t keep her in the breeding box for too long, only for the time it takes for her to release the fry.

Guppy Fish Pregnancy Care

It’s clear that stress is a major risk factor in pregnancy and doing your best to keep your fish comfortable during the gestation period and the labor process is crucial to ensure a problem-free labor.

Female guppies can become pregnant again within a few hours after giving birth, which earned them the name million fish because of their prolific breeding abilities.

Moreover, females can store the sperm of the male for a long period and get pregnant multiple times from a single insemination.

Proper pregnancy care, however, is important to avoid labor complications, fry deformities, and illnesses that can cause the death of your female guppy.

Reducing stress, keeping the water clean, monitoring for diseases, offering stable water parameters and a healthy diet will reduce not only pregnancy-related complications but will also maintain the health of your fish.

Fish with deformities or health issues should not be allowed to breed as both can be passed down to baby guppies.

Likewise, excessive breeding can also put a strain of the female guppy, eventually shortening her lifespan.


There are many reasons why your guppy fish may die just after giving birth, some of which are pre-existing conditions (e.g. an illness), some are related to complications that arise during labor (e.g. fry getting stuck in the birth canal), while others have to do with inadequate keeping conditions.

In any event, making sure your pregnant guppy fish are well cared for by eliminating stress, ensuring healthy water conditions and offering them a healthy diet can minimize the chances of something going wrong during labor.

Always monitor your fish for diseases and, whenever possible, avoid buying guppy fish that are already pregnant. Buy your guppies from a reputable breeder that breeds healthy fish.

Updated: January 10, 2022
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