Guppies are also known as million fish. The reason behind that is guppies breed out of control when we keep male and female guppies together in the same tank. A female pregnant guppy can store the sperm of the male guppy and can use that sperm to be pregnant for the rest of their life.
A female guppy can give birth to 5-200 fry at a time. So, if you have a male and a female guppy in your tank, your female guppy will soon become pregnant for sure. So, knowing all the behaviors and problems of a pregnant guppy fish is necessary.
So, Why is my pregnant guppy moving up and down? Let us find out.
Stress due to environmental factors is the reason behind your pregnant guppy moving up and down. However, guppy fish show such swimming behavior when about to release the fry. Ensure adequate water temperature, and create lots of hiding spots to prevent your guppy fish from such issues.
This article will discuss the reason behind pregnant guppy moving up and down and the swimming behavior of a pregnant guppy fish. So, let us get into it.

Contents
Pregnant guppy fish swimming behavior.
You will find your pregnant guppy fish staying and swimming at one spot in your aquarium.
They will spend most of the time staying at the hiding spots to hide from other tankmates.
Pregnant guppies also swim erratically when they are about to give birth.
Pregnant guppies may find it hard to swim and show such swimming behavior because of getting much pressure on the swim bladder.
Also read: Is My Guppy Pregnant?
Is It normal for pregnant guppy moving up and down?
It is normal for your pregnant guppy to show such swimming behavior when they are about to release the fry until they become inactive and stop eating.
Your guppy fish may be showing such swimming behavior because of stress due to environmental factors.
Pregnant guppy usually hides by staying and swimming at one spot when they are about to release the fry but can also show erratic swimming behavior.

Ensuring adequate living conditions is necessary for your pregnant guppy’s good health.
Also read: 8 Signs Guppy Is About To Give Birth.
What are the reasons behind pregnant guppy moving up and down?
These are the reasons behind your pregnant guppy fish moving up and down:
- Your pregnant guppy is under stress.
- Your pregnant guppy fish is about to release the fry.
- There is a presence of aggressive fish in your guppies tank.
- Your pregnant guppy is finding it hard to swim.
Stress
Stress is the primary reason your pregnant guppy fish moves up and down.Â
Usually, female pregnant guppies come under stress naturally, and there is nothing we can do to lower the stress.
But, Inappropriate environmental factors can make the natural stress level of pregnant guppy get into a high-stress level.Â
These are the reasons behind your pregnant guppy coming under stress:
- Lack of hiding spots
- Inadequate water temperature
- Unstable water temperature
- Presence of aggressive fish.
- Irregular supply of food
- Overcrowded tank
Also read: What To Do If My Guppy Is Stressed?
Pregnant guppy fish is about to release the fry.
Female pregnant guppy also shows such swimming behavior when they are about to release the fry.
Maybe they are going to release the fry in some days or hours.
Your pregnant guppy starts avoiding eating and shows erratic swimming behavior when they are about to release the fry.
Also read: Can Female Guppy Give Birth Without Male?
Presence of aggressive fish in guppies tank
Aggressive fish in your pregnant guppy tank can make your guppy fish move up and down.

Your guppy will come under stress, and in case of protecting themselves from the aggressive mate, they can show such swimming behavior.
Also read: Can Guppy Fish Live With Angelfish?
Pregnant guppy is finding it hard to swim.
The mass of pregnancy may be putting much pressure on your pregnant guppy swim bladder, making it harder for them to swim.
It is normal in pregnancy until your guppies show the behavior of becoming lethargic and losing their appetite.
How to prevent our pregnant guppy from showing such swimming behavior?
Pregnant guppy fish showing such swimming behavior is normal when they are about to release the fry.
We recommend separating your pregnant guppy into another tank or a breeder box when they release the fry.
However, you can ensure these things to confirm that your pregnant guppy fish is living comfortably and not showing such behavior because of some issues:
- Ensure adequate water parameters.
- Avoid overcrowding your guppies tank.
- Create lots of hiding spots.
- Avoid adding aggressive fish to your guppy’s tank.
- Feed them regularly.
Adequate water parameters
Pregnant guppy fish require adequate water parameters to release the fry.
Not getting the required water temperature can result in guppy fish holding the fry for a long time and coming under stress.
Provide your pregnant guppy fish water temperature between 76-82°F.
Make sure to keep the water temperature stable by adding a heater to your guppies tank.Â
We recommend using the Fluval M200 Submersible heater for your tank.
You can buy this product at amazon: Fluval M200 Submersible Heater.
Also read: What Is The Ideal Water Temperature For Guppies? (Complete Guide)
Avoid overcrowding your guppies tank.
A pregnant guppy will not get able to release the fry in an overcrowded tank and will come under stress.
Your pregnant guppy will need enough space to live and swim comfortably.
To ensure that you are not overcrowding your guppies tank, follow the one-inch one-gallon rule, which means one inch of fish per gallon of water.
Following the one-inch one-gallon rule will ensure that you are not overcrowding your guppies tank.
Create lots of hiding spots
Female pregnant guppies require a hiding spot to hide from other tankmates and release the fry.
Ensure provide your pregnant guppy lots of hiding places so that they can release the fry there.Â

You can add many live aquatic plants to your guppies tank to ensure hiding spots for your pregnant female guppy.Â
You can also add aquarium decors like terra cotta pots, driftwood, sunken ships, etc.
There are many options available for adding hiding places in your guppy fish tank, of which rock caves are good.
You can buy rock caves at amazon: Stackable Aquarium Decoration Rock Caves.
Also read: Do Guppies Need Hiding Places?
Avoid adding aggressive fish.
Avoid adding aggressive fish like angelfish to your guppy’s tank, as it can make them come under stress.
Aggressive fish will chase your pregnant guppy constantly, making them come under stress.
A pregnant guppy being under stress for a long time can also result in the abortion of the guppy fry.Â
These are some best tankmates of your guppies you can consider adding to their aquarium:
- Neon tetra
- Shrimp
- Mollies
- Platies
- Gourami
- Zebra danios
Also read: Can Guppy Fish Live With Molly?
Feed your pregnant guppy regularly.
Feeding your pregnant guppy in a regular manner is necessary to ensure their good health.
Usually, your pregnant guppy will not get able to eat much because of the space taken by the guppy fry inside them.
Consider feeding them 3-4 times a day in a small quantity to prevent the water from getting polluted from leftovers.
Also read: Why Is My Pregnant Guppy Not Eating?
Pregnant guppy care.
Taking good care of the pregnant guppies is necessary for both the pregnant guppy and the fry.
When you detect the gravid spot getting more darker and enlarged in size, your guppy is about to release the fry.
We recommend placing your pregnant guppy in a separate tank by this time so that they feel safe and comfortable.

Your guppy will avoid eating when they are in labor, which is entirely normal.
Feed your pregnant guppy 3-4 times a day in small quantities to keep them healthy and strong.
Avoid keeping your pregnant guppy in an overcrowded tank or a tank with aggressive fish, as it can make them come under stress, resulting in abortion.
Once your pregnant guppy releases the fry, separate the mother guppy from the fry immediately, as guppies lack parental instinct and will feed on their fry.
Also read: Should I Separate My Pregnant Guppy?
Conclusion:
Pregnant guppy moving up and down is not a matter of concern until they become lethargic and avoid eating completely.
Stress can also be the leading reason your pregnant guppy moves up and down, so ensure adequate living conditions for your pregnant guppy.
Provide your pregnant guppy with a warm water temperature between 76-82 °F.
Ensure to create a lot s hiding spots for your pregnant guppy so that they can release the fry comfortably.
Also, avoid overcrowding and adding aggressive fish to your guppies tank to prevent your pregnant guppy from coming under stress.