Pregnant Guppy Fish Care

This article contains everything you need to know about pregnant guppy fish. I will cover every thing you need to know from signs your guppy is pregnant, how to care for your guppy and more.

Guppy fish can quickly over stock your aquarium tank. It is very important to spot a pregnant guppy and know how to care for her and her babies.

pregnant guppy guide

How To Tell If A Guppy Is Pregnant?

The most obvious way to tell if your guppy is pregnant is to look if the guppy has a gravid spot, If it does this is a clear indication the guppy is pregnant. The other obvious sign is that the guppies belly is growing larger.

Below are signs that you can look out for to tell if your guppy is pregnant.

  • Gravid Spot
  • Belly Growing Larger
  • Becomes More Aggressive

I will now go in to each one below

Gravid Spot

The gravid spot is located at the bottom of the guppies belly.  If the spot is dark and grows larger over time the guppy is pregnant.  Below is what a gravid spot looks like

guppy Gravid Spot

Belly Growing Larger

As with any pregnancys the guppies belly will grow larger and larger as the pregnancy progresses.  As the guppy fry (Babies) grow larger they need more room and cause mum’s belly to grow.

Below is a picture I took of one of my pregnant guppies.

guppy pregnant belly

A guppy with a large belly could also be a sign the guppy has constipation. If your guppy is constipated check out this article for more information.

Becomes More Aggressive

Some times guppies become more aggressive when pregnant, this is because their motherly instinct is kicking in and they want to protect their young. They will chase any other fish away that comes near them, male and female.

YouTube video

Pregnant Guppy Behavior

When a female guppy is pregnant you
can expect some behavior changes which will include.

  • More Aggressive To Other Fish
  • Hiding
  • Stay Away From Other Fish
  • Not Eating
  • Swimming Less

When a guppy is pregnant parental instincts will kick in almost strait away, The mum is trying to protect her unborn fry.  She will also hide and distant herself from other fish

As with us humans guppy will have spells when they feel sick, when this happens they will skip meals.

They will also become less active in order to conserve energy

How Long Are Guppies Pregnant Before Giving Birth?

If you have identified that your guppy is pregnant you will want to know how long are guppies pregnant before giving birth. This period of time when a guppy is pregnant is called the gestation period.

What is the gestation period of a guppy? A typical female guppy will be pregnant for 21 to 30 days but this can vary considerably.  A Friend of mine has a guppy that took three months to finally give birth.

So if your guppy has gone past day 30 and had not given birth do not worry.

A female guppy will be pregnant for about 25 – 35 days before giving birth.  So you have a rough idea when to expect the babies.  There are a few signs which you can look out for which include

When To Separate A Pregnant Guppy

To give your guppy the best change of having a successful pregnancy and birth you should separate the female guppy from other fish.

You should ideally separate or isolate the female guppy from other fish a few days after you notice they are pregnant.

The main reasons for separating your pregnant guppy include

  • Reduces Stress Of Guppy
  • Increases Chance Of Successful Birth
  • Increased Chance Of Fry Surviving

When To Put Guppy In Breeder Box

A guppy breading box is a small container that sits inside your aquarium and quarantines off the pregnant female from other fish. You should put a pregnant guppy in a breeder box roughly three weeks in to their pregnancy.

Below is a picture of a Senzeal breading box which I have used many times. You can buy from amazon here.

Guppy Breading Box

If you want to learn more about breeding boxes for guppies take a look at this article I wrote about them.

Pregnant Guppy Labor Signs

The signs that your guppy is in labor inclide

  • Square Bulge Just Below Her Gills
  • Change Shape Of Belly
  • Hiding
  • Rubbing On Objects
  • Looks Nervous
  • Flexes Spine
  • Aggressive Towards Other Fish

The most obvious sign your guppy is in labor is a square bulge just below her gills.  This changes in shape due to the contractions they will be having.

The easiest sign your guppy is about to give birth is hiding in plants or ornaments in the tank.  It is not normal for a guppy to hide so if you see the female hiding when she is heavily pregnant then she is most likely in labor.

YouTube video

Your guppy will also rub up against plants and ornaments in your tank, they do this to try to calm themselves and make them feel more comfortable.

They also constantly flexes her spine or moving her tail up.

Signs Guppy Is About To Give Birth

If your female guppy is showing two or more of the following symptoms then there is a good chance she is in labour and is ready to give birth.

  • Belly Shape Change
  • Swimming In Place
  • Hiding
  • Rubbing
  • Nervous
  • Flexes Spine
  • Refusing To Eat
  • Shaking or Shivering
  • Aggressive Behaviour

The most obvious sign your guppy is close to giving birth is that the shape of their belly changes to more square and also looks bulkier.  The reason this happens is because the guppy is pushing her tummy to try to get the fry out.

Also if you see them swimming / shaking in the same spot this is another common sign.  At this time the female guppy will also hide because they are nervous and do not want to be disturbed.

If any fish come near her during this time she will most likely charge at them to drive them away.  This is why it is recommended to separate the pregnant guppy and put them in a breeder box until they have given birth.

How to Care for Baby Guppies?

Now that your fry have arrive you will want to take a look at them to see if they are healthy or not.

How To Spot Premature Fry

A female guppy will ideally give birth after 21 days, If she give birth before that her fry might not be fully developed.

You can tell is a fry is premature if there is a yellow sack just behind its eye.  This area should be silver colour. An example of a premature fry is shown below.

premature guppy fry

How To Spot Healthy Fry

A healthy fry will not have a yellow sack behind their eye and will look like the fry in the picture below.  Another sign the fry is healthy is that they are active as soon as they have been born.  Healthy fry also tend to swim upwards in the tank.

healthy guppy fry

How To Help The Guppy Fry Survive

To help guppy fry thrive and have the best chance of survival you should

  • Feed Them Quality Food
  • Move Them To Seperate Tank
  • Give Them Plenty Of Hiding Places
  • Ensure The Water Quality Is Good

Baby guppies are very hungry after they have been born and they can eat food at an alarming rate.  It usually takes a fry 20-30 minutes to fully digest and process a meal, which means the fry is ready to eat every 30 minutes.

For a few days after the fry have been born I recommend you feed them up to 5 times a day.  A good tip is to feed them high quality fish flakes like TetraColor Tropical Flakes but before you put the flakes in the take crush them up so the fry can swallow them easier.

Adult guppies will eat the fry if they see them (Including the fry’s mum) so it might be a good idea to move the fry to their own tank if you want them all to survive.  Once the fry has grown a little bit the other fish will not see them as food.

Make sure to add plenty of hiding places for the fry as this will give them the best chance of survival.

Best Food For Guppies

For the water conditions make sure the water temperature is between 72-82 °F (22-28 °C) this is the perfect temperature for guppy fry to thrive in.

Next check the pH levels in the water.  I have found the easiest way to check the pH level of your aquarium water is to use a digital pH Meter

Change 25% of the tanks water two weeks after the fry are born.  This will help to make sure the water is fresh for the fry.

Frequently Asked Questions

How Do Female Guppies Get Pregnant?

A male guppy can develop their sexual organs as early from three weeks old. The male guppy will deposit sperm in to a female guppy, the female guppy will then store the sperm to use over the course of up to eight months.

Fertilisation of the fish eggs will occur inside the female fish which is a different process from most other fish (Fertilised externally)

Male guppies will typically chase a female around the aquarium when they are ready to mate. The female guppy will try to swim away from the males until they are exhausted and are unable to, it is at this time the mating takes place.

male chase female guppy

Even when the female guppy is pregnant the males will keep chasing the females. Research has found that the female participates in the mating by squeezing and holding the gonopodium in place.

Why Do Male Guppies Chasing Pregnant Female Guppies?

Male guppies chase female guppies when they want to mate, but why do they chase them when they are pregnant already?

Males will chase females that are close to giving birth so they can make them pregnant again.  Yes they can begin the next pregnancy whilst the female is currently pregnant.

As you can imagine this can be very stressful for the female, she is getting ready to give birth and she has males harassing her and making her swim away making her tired.

This is why you should separate your female in to a breeding box as this will be less stressful for her as the males will not be able to chase her anymore.


Hello, I'm Jason. I'm the guy behind I volunteer at my local fish shop and I created this site to offer tips and advice on the fish I care for.