How Long Are Guppies In Labor? (Explained)

Female guppies usually spend between 2 and 8 hours in labor. Sometimes labor can last as long as two days. Many factors can affect how long a guppy’s labor takes including the size of the female, the temperature of the water, and whether or not environmental factors are stressing her.

Eating Daphnia
Eating Daphnia

Guppies have been one of the most popular fish in the freshwater fishkeeping hobby for decades. The guppy’s easy-going attitude, bright coloration, and simplicity to breed have cemented their popularity.

I have been keeping and breeding guppies for over 30 years. Over that time I have probably watched hundreds of female guppies give birth to thousands of guppy babies. I have always been amazed how such a little fish gives birth to so many babies in such a short time.

How Long Is A Female Guppy In Labor?

Female guppies are usually in labor for between 2 and 8 hours. Labor is usually an uncomplicated affair with the guppy giving birth to between 40 and 80 babies. Sometimes however things can take a little longer than they should and a female guppy can be giving birth for up to a couple of days.

The best thing to do is just to leave your female guppy to it. She won’t appreciate being picked up in a net and plunged into a breeder box.

If you believe your female guppy is struggling, and the labor is taking a long time, check a couple of the water parameters to see if there are issues with the water. First, check the temperature.

The warmer the better. If the temperature has fallen below 76°F (24°C) consider turning your heater up a couple of degrees. If her water is too cold she may not be able to pass the babies correctly.

Equally, if the water temperature is above 82°F (28°C) consider either turning the heater down or trying to cool the water temperature. Much like when the water is too cold, if it is too hot, your female guppy may be stressed.



Other factors that can cause a female guppy to be in labor for longer than usual are;

  • Stress caused by being moved to a breeder box
  • High levels of nitrates in the water
  • Bullying from another fish

Stress caused by being moved to a breeder box

I am not a massive fan of breeder or birthing boxes for guppies. The problem is, we typically take a heavily pregnant fish and, a few days before she is due to give birth, drop her into a tiny, floating plastic box that offers her no cover.

Female guppies can and will die if they are stressed out prior to birthing. I never use breeder boxes and I wouldn’t recommend anyone else to either

High levels of nitrates in the water

Our filters convert fish waste (ammonia) which is very toxic, into the less toxic nitrate. Nitrate is less toxic than ammonia, but only at low levels. It is up to us aquarists to keep the nitrate levels low by changing water on a regular basis.

If the aquarium housing our female guppy has a high level of nitrates because we haven’t been changing the water frequently enough, it can be incredibly stressful for the fish. I recommend changing about 30% of the aquarium water every week, especially in an aquarium where a female is about to give birth.

Newborn baby fish means an increase in the amount of fish waste in the aquarium!

Bullying by Another fish

A female guppy is at her most vulnerable in the days and hours before she gives birth. If she is constantly being harassed by another fish, she won’t feel safe enough to release her babies. This can lead to long, drawn-out labor, and potentially the death of the female guppy.



Signs A Female Guppy is Preparing For Labor

Female guppies are usually pregnant for between 25 and 35 days. The actual number of days often depends on water temperature. It can be almost impossible to work out which days a female guppy conceived, so knowing the signs she is about to give birth can be useful.

In the final days before a female guppy gives birth, her abdomen will become so swollen that it almost looks square. It is known as being ‘boxy’. A heavily pregnant female is unmistakable.

Another sign a female is due to give birth is if she starts to hide. Female guppies close to giving birth will often try to hide from the other fish. They may sit in the corners of the aquarium, behind decorations, or in a clump of plants.

In Conclusion

Guppy labor is usually a fairly uneventful act lasting between 2 and 8 hours. Often we aquarists don’t even notice she is in labor, we just see new arrivals swimming around.

I don’t remember the first time I watched one of my female guppies give birth, but I know the first 15 or 20 times I did it, I was incredibly nervous. I would constantly check the aquarium to see if she was still in labor. These days I tend to be a lot more relaxed about guppy labor. As long as the water parameters are correct, the guppies are normally only in labor for a few hours.

If your female guppy appears to be taking longer than expected to give birth, take a few minutes to see if you can work out why. If you can solve the problem, you may help save your guppy’s life!


About the Author

I’ve been keeping, breeding, and showing tropical fish for nearly 30 years. Over that time I’ve done it all! I’ve had great success and I’ve made some really foolish mistakes (like the time I bought an Asain Walking Catfish). Read more…
Richard James
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