How are Guppies Born?

Guppy pregnancy is a must-read topic, seeing how prolific guppies are at breeding. Healthy guppy females living in optimal environmental conditions will give birth every month and are capable of producing thousands of offspring every year.

There is also an impressive market for guppies, providing numerous strains with varying features, coloring, and patterns. If you’re looking to breed guppies selectively, you’re on the right business floor.

But what happens during guppy pregnancy, and how are fry produced? Let’s have a look into guppies’ breeding behavior.

How do Guppies Give Birth?

Guppy pregnancy undergoes several phases, and you can see it progressing as the labor moment approaches. The duration of the pregnancy depends on the guppies’ environmental conditions. If they have a balanced diet, consistent meals, and warmer waters, they may produce fry every 20-25 days.

If the water is slightly colder, the pregnancy duration may increase to 30 days.

Regarding the birth itself, here are some of the core facts:

– The Pregnant Guppy Hides

This is typical behavior that all pregnant guppies will display. The hiding behavior becomes more visible towards the end of the pregnancy. Your guppy female will look for hiding spots among plants, rocks, and caves, driven by the instinct of finding a safe place for the fry.

When bullied by males, they resort to the same behavior since pregnant females can grow irascible with time. Males are also not famous for their social awareness, so they can’t tell when a female is already pregnant and not interested.

This means that you should monitor your tank dynamics to see whether the male stresses the female too much. It can happen, which will cause the female to retreat into hiding, refuse food, and experience a lower immune system, causing a variety of health issues.

The hiding behavior may also be evidence of bullying, ammonia poisoning, and overall fish stress caused by poor water quality. To eliminate these problems off the list, look for additional signs of guppy pregnancy, including:

  • Inflated belly that grows with time
  • The existence of the gravid spot (a dark area in the rear part of the abdomen)
  • Increased aggression during pregnancy, mostly directed towards males, etc.

– Start Giving Birth

You can tell that the female guppy is getting into labor via:

  • Appetite changes – The female will generally stop eating as soon as the labor sets in. This is often the most compelling sign of labor, along with the changes in swimming and body movements.
  • Swimming in place – The female will look for hiding and will swim in place, only displaying subtle body movements to keep itself floating. She will also display rapid body movements and contractions, which can last between 4 to 6 hours. More complicated deliveries can last way longer than that.
  • Rapid breathing – Guppies will display rapid breathing throughout their pregnancy, but particularly during labor.

As soon as your guppy female goes into labor, you have 2 decisions to make. You either allow the female to give birth into the main tank or move it into a breeding aquarium. It all depends on your goals. If you’re not that interested in keeping or selecting the fry, allow the female to give birth in the main tank.

Adult fish will eat most of them soon after birth. If, instead, you want to keep the fry to start a new tank, turn them into gifts for your friends, or sell them for profit, relocate the female.

This will allow you to secure the fry and provide them with optimal living conditions to grow healthy and uninhibited. You can introduce them to the main aquarium once they’re big enough for other fish to no longer see them as prey.

– Guppy Fry Are Born

As soon as they’re born, the fry’s instincts will immediately kick in. They will scatter throughout the tank and look for hiding. It’s essential to provide them with plants, caves, rocks, wood, and other tank decorations where they can hide, inspect their environment, and gather their strengths.

These hiding places will keep them safe from other fish in the tank and keep them comfortable while they are still vulnerable.

– Guppy Fry Start Swimming

The guppy fry are all prolific swimmers right from the beginning. They possess high energy and will use it to their advantage, torpedoing through the water on the lookout for hiding.

Their agility and speed are their best defense mechanisms against predators.

– Guppy Fry Start Eating

Guppy fry are ready to eat as soon as they’re born. Their diet is similar to that of guppy adults, with slight variations here and there. For instance, the fry will require a more protein and fat-rich diet, which would typically cause adult guppies health issues.

You should provide your guppy fry with a balanced, omnivorous diet and add a bit more protein and fat during their first 2-3 weeks of life. By week 4, they should transition towards an adult-specific diet.

Do Guppies Give Birth All at Once?

Guppies give birth to all guppy fry in one session, but not at once. Don’t expect all the guppy fry to pop out of the female in bulk. They will emerge gradually over a period of several hours. How long that will take depends on how many fry there are and how experienced the female is.

First-timers may produce 30 fry within 2-3 hours. That number may increase to 80 or even 100 in the same timeframe for more experienced females.

How Many Guppy Fry Are Born at Once?

The number of fry a female will produce depends on various factors like:

  • The pregnancy number – If this is your guppy’s first pregnancy, expect a low number of fry. Guppy females can produce as low as 2 fry during their first pregnancy. This number will then increase consistently over time. Guppies can produce up to 200 fry in one go.
  • Genetic makeup – The female will produce more fry if its mother did the same. Breeding prowess is one of the core factors that guppy breeders look for during selective breeding.
  • Environmental conditions – Warmer waters and balanced and nutrient-rich diets will dramatically improve your guppies’ reproductive rates over time.

Why do Guppies Eat Their Fry?

Adult guppies eat their fry because they see them as prey. Guppies will eat pretty much any creature that’s small enough to fit their mouths and fry qualify for that ‘honor.’

Guppies also have no innate aversion towards cannibalism. They don’t shy away from eating their own under specific circumstances. If you want to save your fry for later use, I suggest providing them with the right conditions they need to survive post-pregnancy.

These include having plenty of plants and hiding places in the main tank or moving the pregnant female into a breeding tank when labor approaches.


Guppies are fantastic breeders, probably the most prolific in the livebearer family. If you’re planning on starting a selective breeding business, there are no better candidates for the job.

If you’re interested in guppy breeding and learning more about selective breeding, check out my related articles detailing these subjects.

avatar Noah
I’m Noah, chief editor at VIVO Pets and the proud owner of a playful, energetic husky (Max). I’ve been a volunteer at Rex Animal Rescue for over 2 years. I love learning and writing about different animals that can be kept as pets. read more...

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