How To Tell If A Female Guppy Is Pregnant: 7 Common Signs

In this article, you’re going to find out exactly how to tell if a female guppy is pregnant. You’ll learn what signs to look for in the early signs of pregnancy, as well as how they’ll change as time goes by.

So keep reading to find out everything you need to know!

How To Tell If A Female Guppy Is Pregnant

There are lots of different ways you can spot if your guppy is pregnant. However, while some of them are a clear sign that your guppy is pregnant, some could be caused by multiple conditions. So make sure you’re looking for a few signs when deciding whether your guppy is pregnant or not.

In short to spot if your guppy is pregnant, look for signs of mating, a noticeable gravid spot, a bulging belly, they’re more aggressive, swimming in place, rapid breathing, and males in the tank.

Here are some of the most common signs in more depth.

You See Her Mating

This is one of the clearest ways that you’ll know your guppy is mating. And when you notice the deed is being done. Before mating, the male is likely to chase the female around the tank.

Once he’s close enough, he’ll erect his anal fin, which will then go into the female’s underbelly, and she’ll become impregnated.

However, if you don’t see this, don’t worry. It can happen extremely quickly, and most fish owners don’t notice.

There Are Males In The Tank

And obviously, another indicator that your guppy is pregnant is when there are males in the tank. Guppies are livebearers that give birth roughly every 30 days. If you’ve got males in your tank, then the chances are, they’ve already impregnated your guppy.

However, even if there aren’t males in the tank, it doesn’t mean your guppy isn’t pregnant. Perhaps she got pregnant before you bought her.

Their Gravid Spot Changes

The gravid spot is located near your guppy’s butt, and it’s also an indicator of your guppy’s pregnancy. Around the 2 week mark, it should appear to be darker.

So make sure you’re always keeping an eye on your guppy’s gravid spot. If you notice it starting to change color, then it’s another sign that your guppy is pregnant.

Near the end of pregnancy, the guppy fry may become so developed that you can even see little dots in the gravid spot, which are the fry themselves.

After giving birth, the gravid spot won’t disappear completely; however, it will fade and sometimes get smaller.

Their Belly Will Begin To Bulge

As the fry in their stomach begins to grow, your guppy’s belly will begin to bulge. This shouldn’t happen all at once, however, but gradually over a couple of weeks. However, just because your guppy’s belly is bulging, it doesn’t mean that they’re pregnant.

It could also be a sign of bloating, constipation, swim bladder disease, and possibly even dropsy in some cases.

Swimming In Place

Another common sign that your guppy is about to go into labor is that you’ll notice she appears to be swimming in place.

While her body may look like it’s swimming, the fish herself will remain in one spot. At this point, she should already be somewhere safe and comfortable because labor is imminent.

They’ll Become More Aggressive

You may notice that your female becomes more aggressive when they’re pregnant, especially towards males that continue to try and mate with her. This could be in the form of chasing them, but in more severe cases, they may also begin fin nipping as well.

(Find out more about guppy aggression and fighting.)

Rapid Breathing

You may also notice that your guppy’s breathing starts to become more rapid when they’re pregnant as well. Once again, this is more likely to happen as they are further along in the pregnancy.

Guppy Behavior Before Giving Birth (What Are A Pregnant Guppy’s Signs Of Delivery)

As well as noticing the signs above, before your guppy gives birth or goes into labour there are going to be more signs. So if you notice the following signs, the chances are that a lot of guppy fry are very imminent.

Body contractions, hiding, a more angular body, and reluctance to eat are all signs that your guppy is about to give birth.

Body Contractions

If you notice that your guppy is having body contractions, then that’s one of the clearest indicators that she’s about to give birth and that she’s currently in labor.

The way you can spot body contractions is to watch her body. If the muscles are tightening, then relaxing over and over again, then she’s having them.

However, it’s important to note that this can go on for a while before she gives birth.

They’ll Try To Hide

When your guppy is about to go into labor, they’re going to try and hide from other fish in their tank. So when the contractions begin, you may not be able to find them as easily.

They do this because they don’t want other fish in the tank to aggravate them and act aggressively while they can’t defend themselves. Once again, this is why it’s a good idea to move them to a separate tank or somewhere safe when they’re pregnant.

As well as hiding, you may notice your guppy trying to isolate herself from the other fish. She’ll normally favor being near the heater, where it’s warmer; however, any corner of a safe place in the tank will do.

Her Body Will Become More Angular

As she moves into the last stages of her pregnancy, you’ll also notice that her belly starts to become more angular instead of round. When you notice this happening, then you can be sure that she is very close to giving birth.

Reluctance To Eat

Near the end of pregnancy, you may also notice that your female no longer wants to eat. She may avoid food or spit it out shortly after consuming it.

Either one is a sign that she is close to delivering her fry.

Is Your Guppy Pregnant Or Fat?

When you notice that your guppy looks bigger than usual, it’s always a good idea to ask yourself whether she’s pregnant or whether it’s something else. Fortunately, there are a few ways you can figure out what it is.

Are There Males In The Tank?

First things first. Are there males in the tank? If there are, then there’s a good chance you’re dealing with a pregnancy. However, even if there aren’t males in the tank, it doesn’t mean she’s not pregnant.

She may have been in the early stages of pregnancy when you purchased her, or she may have some sperm stored in her. In fact, sperm can be stored for months, waiting for the optimal time to become pregnant.

(Find out more about keeping male and female guppies together.)

Can You See The Gravid Spot

Another way to know is to check for the gravid spot. If the gravid spot is noticeable then this is the biggest tell-tale sign that your guppy is pregnant and not fat. So if you do notice her gravid spot, begin preparations for fry in your tank.

Is She Sick?

Lastly, make sure that your female isn’t sick. There are a number of different reasons that your guppies abdomen might be swelling. And not all of them are due to pregnancy.

For example, if your guppy becomes extremely constipated, then it’s going to bloat her belly. As well as this dropsy will also cause the belly to bloat. And it could also be swim bladder disease. To make sure your guppy is pregnant, you should check for the sign of pregnancy, as well as have a knowledge of illnesses that can cause a bloated belly to occur.


Here are some frequently asked questions people often have about their female guppy bring pregnant!

How Long Is A Female Guppy Pregnant

Female guppies usually have a pregnancy lasting about 21 to 30 days. But, it could change depending on how hot the water is, how old and healthy the female guppy is, and what genes the guppy has. Usually, the pregnant guppy will pop out around 20 to 40 baby guppies, called fry, and these little guys can swim and feed themselves right after birth.

How Can You Help Prepare A Guppy For Birth?

When your guppy is about to give birth, there are a few things you have to do to make sure everything goes well. First, keep the water clean and ensure it’s not stressing the fish out. Also, get rid of any mean fish that could hurt her or her fry. Also, make sure you’re feeding her a mix of good food like flakes, live or frozen snacks, and veggies to keep her healthy and help her babies grow. 

When it’s almost time for the babies to pop out, set up a new tank with a gentle filter and lots of places to hide. And remember to keep an eye on your guppy and watch for any signs of stress. Follow these steps, and you’ll be set for a safe and happy delivery for your guppy and her fry.

Should You Isolate Pregnant Female Guppies?

Put your pregnant guppy in a separate tank. You can pay more attention to your pregnant guppy’s needs and take better care of it than if it were in an aquarium with other fish, where they would be competing for food, space, and survival.


Now you know all the signs to look for when your guppy is pregnant. And remember, if she is pregnant, you should try to move her somewhere she can be left alone in peace.

About the author

Hey there! I'm Antonio, the passionate owner and chief editor of Betta Care Fish Guide. With over half a decade of hands-on experience, I've become your go-to expert for all things betta and tropical fish.

Over the past 5 years, I've not only kept bettas and other tropical fish but also connected with a diverse network of hobbyists, seasoned fishkeepers, and even veterinarians.

Now, I want to help other beginner fish keepers who had the same questions as me when they were just starting out! So they can save themselves a ton of time and keep their fish happy and healthy!