Pregnant Guppy Fish 101: Identification and Care Guide (2024)

Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: June 8, 2024
Review Process and Evaluation Criteria
We conduct hands-on testing for all the products highlighted in our reviews and guides. Through anonymous product ordering and involving an independent team of testers, we gather direct experience to offer recommendations backed by data.

Are you considering breeding guppies? Maybe your guppy has already begun reproducing on its own and you’re wondering what to do next?

Never fear, we’ve all been there when we think our all female guppy tank has the surprise male guppy. Next thing you know you have to learn all about pregnant guppy fish care, luckily for you that’s where we come in.

If you’re looking for a guide to how to care for a pregnant guppy, how to tell if a guppy is pregnant, and how to best deliver healthy fry, read on!

Article Summary

  • To determine if a guppy is pregnant, look for a dark gravid spot on the fish’s belly, which will darken as the fry inside grow.
  • Female guppies are live-bearers and carry their young internally for 21-30 days before giving birth.
  • Use a separate breeding box for the guppy during delivery to minimize stress.

How To Tell If A Guppy Is Pregnant

Male and Female Guppy
Male and Female Guppy(1)

So how can you tell if a guppy is pregnant?

If your guppy is pregnant, there are a notable series of signs you’ll see as the pregnancy progresses. The most obvious sign is known as the gravid spot, which appears as a dark spot on the underside of the fish. 

The guppy gravid spot will gradually darken as the guppy fry inside of your pregnant fish grow larger. Eventually you may even be able to see tiny fry eyes peeking out!

Female guppies are live-bearing fish, meaning that they carry their young internally for several weeks after being fertilized. Once the guppy fry have reached a sufficient maturity after 21-30 days, they will hatch and swim freely from their mother. When a guppy is pregnant, she will grow in size until finally ready to give birth.

Breeder Box

As soon as you have noticed your guppy’s pregnancy, consider preparing a breeder box. These breeder boxes are separate tanks that you’ll be moving the female into before she gives birth, and what you’ll be raising the fry in afterwards.

When A Male Guppy And A Female Guppy Love Each other Very Much…

If you’ve seen a few of your male guppies starting to chase around the female guppies, you may be in for some new members of your aquarium family. What at first may look like aggression is in fact the mating behavior that adult guppies use to show their affection.

Guppy Chasing Behavior

The typical breeding routine for guppy fish is that the male guppy will chase a female, and upon nearing attempt to extend a modified anal fin (or gonopodium) outwards and deposit a sperm packet into the female’s anal vent. This will occur upwards of 6 times during their mating ritual, ensuring that she’s pregnant.

Pregnant females are then able to store sperm below their anal fin for upwards of a year, during which time these livebearing fish can continually become pregnant again!

What Does A Pregnant Guppy Look Like?

Pregnant Female Guppy
Pregnant Female Guppy

When a guppy is pregnant, it will grow larger over the gestation period of several weeks, in addition to changes in behavior and a darkening of the gravid spot on their belly.

As soon as you notice a droop to the belly and a gravid spot, you’ll know your female fish is full of guppy fry.

Larger Belly

The belly of pregnant female guppies will expand quite a bit throughout the course of delivery. Rest assured that bloating and a boxier appearance are normal pregnant guppy signs. 


A guppy that is simply overweight versus being pregnant will lack the distinctive gravid spot.

How Long Does A Guppy Stay Pregnant

The guppy gestation period can be between 21 and 30 days, depending on the fish. Female guppies are prolific breeders, and can deliver up to 20-60 fry at one time. With up to eight pregnancies possible off of one breeding session, this means that a single female guppy fish can have several hundred guppy babies in one season!

A female guppy fish is able to become pregnant right within hours or having been able to give birth!

Length of Average Delivery

The actual birth process itself can take between two and six hours. During this time, your guppy fish should be giving birth to several fry at one time.

This process may extend by a few hours, but if it has stopped for longer than a day remove the female from the breeding tank so that she can begin to destress.

Newborn guppy fry will emerge as curled up balls and unfurl to swim away. Not all guppy fry will be viable, however. Those that sink to the bottom should be removed from the tank to prevent foiling the water.

Caring for Pregnant Guppy

Giving birth can be an incredibly stressful time for your fish, and as such using a separate breeding box is highly recommended. Prior to the actual delivery itself, your pregnant guppy can stay in the general tank with your other fish.

When to Separate Pregnant Guppy


In order to prevent overstressing your guppy, birthing tanks should be used when she is going into labor, rather than for the duration of her pregnancy. Seeing all the signs of delivery such as body contractions and rapid breathing mean that it is time to move your fish into a separate aquarium.

What to Feed Pregnant Guppy

As your guppy’s belly grows throughout her gestation period, her appetite will shrink. Regardless, you still need to be sure to continue your normal feeding routine of several small meals a day during the gestation period, albeit with less food than you would normally use.

Once in her separate breeding tank, you can pause feedings for the duration of the pregnancy. After she is able to give birth, resume feeding as per usual and be aware that she may need a bit more food than usual.


In addition to high quality fish flakes, consider adding additional nutritious treats such as bloodworms or brine shrimp to round out her diet before she is able to give birth.

How To Prepare For The Baby Guppies

Guppy Giving Birth
Guppy Giving Birth

As the pregnancy progresses, you’re gonna need to prepare for the upcoming fry. Preparing for guppy fry means having one tank ready for the fry to be born, and another set up for the female guppy to recover after giving birth.

For a breeding tank and recovery tank, having a 10 gallon tank should be sufficient. Just make sure to keep the water as clean as possible.


Consider using a test kit to ensure that conditions in the breeding box match those of the main tank, to lessen stress on the mother as she is giving birth.

You’ll only be keeping the female in the birthing tank for a day or so after she is able to give birth, so you don’t need to plan long term with decorating and elaborate set-up. Ensuring that the water is clean and that there is adequate oxygenation should suffice.

Water Conditions

Keeping an ideal set of parameters will help the pregnancy go along smoothly. Keep the water temperature at around 75-78 degrees Fahrenheit to keep her moving along.

Colder water conditions may extend the pregnancy.

However, reaching too high of a temperature can create its own problems as your guppy’s metabolism elevates initially and then lowers as it struggles to cope with the heat.

Water Change

Continue your normal practice of regular water changes and filter maintenance, as dirty water can lead to major complications with a pregnancy.

Consider using guppy grass to help reduce ammonia and provide your pregnant guppy with ample space to hide.

Signs of Delivery

 Signs Your Female Guppy is About to Give Birth

When it is time for your fish to give birth, there are several notable signs. In addition to simply looking heavily pregnant as the baby guppy fish are ready to emerge, her behavior may alter in certain ways.


When your female guppy is pregnant and senses that she is about to give birth to baby fish, she will attempt to find a safe place to hide.

The underwater environment can be a very dangerous place for these small fry, and she’ll do her best to find some place away from other fish such as a cave or alcove underwater.


When your fish is about to give birth, you may be able to notice movement centering around the guppy gravid spot. This guppy behavior is a sure sign that she is getting ready to push those babies out of her body and is ready for your breeding boxes.

Fry Care and Feeding

Fish Food
Fish Food

So your gravid spot has made it all the way to a mass of adorable baby fry, and now what?

Newborn guppies should be kept in their own tank until they have the chance to stand up to other fish in your community tank.

Before then, they should be fed 5 times daily with nutritious foods specifically formulated to help your babies grow. 

Fry Foods

Make sure that you’re purchasing quality foods made for young fry, rather than adult guppies. Your fancy guppies will need a bit more nourishment during their first few years but will eat less, meaning more feedings than normal but with less food.


Keep in mind that even these younger fish will prey on one another. A little bit of cannibalism between siblings is unavoidable in the fish world, but you should have plenty of young fish leftover when they reach maturity.

Fry will grow around .3 inches per month in their separate tank, and will be around .25 inches at birth. They should be around a half an inch before being released into the community tank, and will be sexually mature at around .6″-2 inches in length. 


Do pregnant guppies stay at the top?

Guppies Swimming at the Top of a Tank
Guppies Swimming at the Top of a Tank

If a male has gotten your female guppy pregnant and she is ready to give birth, you may notice her swim upwards and stay around the top of the tank.

This is completely natural for most fish, as she is simply trying to find a safe place to deliver.

If you notice that it is too late and she has begun to deliver, consider adding a floating aquarium plant such as hornwort in which the fry can hide.

After all of the babies have been delivered, you can then scoop them out with a fine net and move them into a safer tank.

How many babies do guppy have

This is a good thing to consider before getting guppies pregnant. How many babies do guppies give birth to? Female guppies can have upwards of 60 babies in a single pregnancy.

After being impregnated by male guppies, they can have 6-8 instances of pregnancy, meaning several hundred babies are possible for each female.

It goes without saying that you should put some serious thought as to numbers before getting your guppies pregnant. If you’ve got two pregnant guppies (which happens more often than you may like) who are ready to give birth at the same time, the number can quickly reach the hundreds.

How do you stop guppies from eating their babies?

Young and Old Guppy
Young and Old Guppy

Using a separate tank is the best way to keep a hungry mom away from her babies after labor.

If you’d like to give her some much-needed extra protein, you can keep her in the same tank as her young with a small mesh screen. This will allow some of them to swim through so that mama can get a snack, but will prevent the majority from being eaten.


Throughout today’s article, we’ve looked at what to do when your guppy is pregnant, how to identify a pregnant guppy fish, and how to care for all the fry that you’ll now have as a proud god-fish-parent.

Remember that keeping guppies is a responsibility that can be more than just a chore and leads to many other fish to enjoy.

Feel Free To Share

As always I hope that you’ve enjoyed this post about pregnant female guppies.

Feel free to share this information with any other fish fanatics you may know, and I wish you the best of luck on your continued aquarium adventures.


Featured Image – Guppy Poecilia reticulata By Holger Krisp – Own work, CC BY 3.0

1. – Male and female guppies. By Anton Melqkov – This is my own picture, CC BY-SA 4.0,

You May Also Like