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How To Tell If My Balloon Molly Fish Pregnant?

How To Tell If My Balloon Molly Fish Pregnant?

Balloon molly fishes are the smallest type of mollies. What’s distinct about them is their bellies naturally appear bloated. So how will you know if your balloon molly fish is pregnant?

Your balloon molly fish is pregnant when its round stomach appears square-shaped. You may see dark spots on the nearly transparent belly if your fish is a light color, which are the eyes of the fry. In addition, your fish will develop a ravenous appetite and experience some physical and behavioral changes.

This article will discuss in greater detail the signs your balloon molly ‘Poecilia sphenops’ fish exhibit when pregnant. I’ll also share some tips on how to care for your pregnant molly before and after she gives birth.

Signs Your Balloon Molly Is Pregnant

Several signs can help you determine if a balloon molly fish is pregnant. This includes physical and behavioral changes. Let’s discuss them below.

Your Balloon Molly Fish’s Stomach Will Have a Square Shape

A clear sign your balloon molly fish might be pregnant is a noticeable change in the shape of her stomach. Typically, if she’s carrying babies, her belly will not have its usual round or oval look.

Instead, it transforms into a square-like shape. This change signifies the growth and development of the fry inside her abdomen.

Your Balloon Molly Fish Will Develop a Ravenous Appetite

A pregnant Balloon Molly fish will experience an increased appetite. This is completely normal and expected as she needs more energy to support the development of her unborn fry.

The balloon molly is a livebearer, which means she doesn’t bear eggs but bears live fry. These developing babies will require adequate food for proper growth and development.

Feeding her small meals throughout the day can help satisfy her hunger while preventing overeating. Remember to monitor water conditions and remove any excess food that remains uneaten to maintain a healthy environment for both your pregnant Molly fish and the rest of your aquarium inhabitants.

Dark Spots Will Appear on the Balloon Molly’s Stomach

A clear indicator of a pregnant molly fish is the appearance of dark spots on her stomach walls. The spots are the eyes of the growing fry. The more the fry, the more spots you’ll see. 

These spots will be more conspicuous on a lighter-colored molly fish. On the other hand, it may be difficult to see them on a darker molly fish.

Your Balloon Molly May Become Aggressive

During pregnancy, your molly fish may become more aggressive, especially toward other fish in the tank. This change in behavior is normal and is often due to hormonal changes that occur during pregnancy.

It’s important to monitor her interactions with other fish closely to prevent any harm or stress to the pregnant Balloon Molly or her tank mates. Providing adequate hiding places and maintaining optimal tank conditions can help reduce aggression during this time.

Remember, if you notice increased aggression from your pregnant Balloon Molly, it’s essential to take steps to ensure the well-being of all the fish in your aquarium.

Your Balloon Molly will Hide from Males

Your Balloon Molly hiding from males is not out of fear, but rather a natural instinct kicking in to safeguard her unborn fry.

Expectant female mollies instinctively avoid further mating attempts by hiding themselves.

This discreet behavior serves as an essential sign if you suspect pregnancy. Moreover, females hiding from males also signifies that the gestation period has advanced and she might soon give birth to her babies.

How To Care for Your Pregnant Balloon Molly Fish

These fish are very delicate and need special care during pregnancy. Inadequate care can cause the death of the mother and the fry in their stomach. 

Here are some tips on how to care for your pregnant balloon molly fish.

Separate the Pregnant Balloon Molly Fish

As soon as you discover a pregnant molly fish, move her immediately to a separate tank to help reduce any stress. 

You should also take some water from the existing tank to its new tank. That way, your molly fish won’t feel like it’s in a completely new environment. A more secure pregnant molly will give birth easily. 

Pregnant mollies feel threatened in the presence of other fishes because they feel the other fish might bother their fry. Keeping them in a separate tank will make them feel safe. 

Make the Tank Conducive to Your Pregnant Balloon Molly Fish

Ensure your molly has many places to hide, she will like the seclusion. You can add plants, shells, or underwater growths that seem natural. You may also want to make it similar to what was in the existing tank to help her adapt easily.

Add extra warmth to the tank using a UV light or any safe heating source. Your molly fish needs a steady temperature that ranges from 23-29 °C (73.4-84.2 °F).

Don’t forget to refill the tank from time to time with clean water. Dirty or stale water is unhealthy for the molly.

Separate the Mother Fish From Her Fry After Birth

Once your molly gives birth in the new tank, it’s best to return her to the old tank because the fry are incredibly small and vulnerable, making them easy prey.

They can also fit into the mouth of most fishes. That’s why they’re in danger of being eaten, even by their mother.

Fry are born alive. They don’t need their mother’s assistance after birth. However, you need to ensure they have food. 

Once they are two to three weeks old, you can reunite them with their mother in the old tank. They will be bigger by then and easily be preyed upon. 

What Is The Gestation Period For A Balloon Molly Fish?

The gestation period of a balloon molly fish is 60 days.

A male Poecilia is ready to mate after 12 months. On the other hand, a female Poecilia can get pregnant at six months. Interestingly, a female Poecilia can also store sperm inside her for months and fertilize her eggs every 30 days

So once the mating season is over, your female molly fish can be pregnant even without a male for months to come. That’s why you need to check up on your fish constantly. 

After delivery, another fertilization can occur in her belly because of the stored sperm. So you may discover that she’s pregnant again.

How to Tell When Your Balloon Molly Will Give Birth?

A pregnant Balloon Molly fish will display a few signs that indicate she is about to give birth. One way to tell is by observing her behavior. As the due date approaches, she may become more restless and swim frantically around the tank.

Another sign is when you notice her hiding or seeking out secluded areas in the aquarium. This behavior indicates that she is preparing for labor and wants privacy during the birthing process.

Additionally, if you closely observe her abdomen, you’ll see the developing fry. These signs can help you anticipate when your Balloon Molly fish will give birth and ensure that you are prepared to provide proper care for both the mother and her newborns.

How Many Babies Can A Balloon Molly Fish Have?

A pregnant Balloon Molly fish can give birth to anywhere from 20 to 60 young fish. The actual number of babies depends on factors such as temperature, diet, the age of the fish, and the number of pregnancies they have had.

Older Balloon mollies that have gone through multiple pregnancies may give birth to more fry compared to younger ones who are experiencing pregnancy for the first time. So if you have a pregnant Balloon Molly in your aquarium, be prepared for a potentially large brood!

Can My Pregnant Balloon Molly Fish Die After Birth?

Balloon molly fish is very delicate, especially during pregnancy. They need attention and care to survive the process. Death after the delivery of new fry is possible for a pregnant molly fish.

Several factors can cause post-delivery mortality in balloon molly fish.

Stress From Other Fishes

A major cause of post-delivery death among molly fish is stress. Balloon molly fish struggle to cope with stress from other fishes. You’d think their male counterparts would help alleviate the stress, but that’s not the case. 

On the contrary, male mollies tend to stress female mollies more, especially after they give birth. It’s advisable to have just one male for every 3 to 4 female mollies in a tank.

Birth Stress and Strain

The birthing process is difficult for almost every animal, and the molly fish is no exception. New mothers can die from exhaustion from stress after giving birth.

Female mollies also feel the birth pangs. Although they can handle it, the pain can sometimes weaken them.

Molly fish usually give birth to many live fry at once, which can be very strenuous. Some weak mollies may not recover after giving birth. So there’s always a possibility that when you send them back to the old tank, they may die.

Illnesses and Defects

There’s every likelihood that a sick, pregnant molly fish will die after giving birth. Molly fish can suffer diseases such as flukes or fin rot. Others may also be genetically weak, so they can’t withstand birth strains.

Aside from these diseases, a fry can get stuck at the north canal. Since there are no doctors to help remove the stuck fry, the mother might die trying. 

The safe birth hours for a molly fish is 1 to 24 hours. However, complications can arise and extend this time, which can lead to death.

You can do little to help a weak molly fish. All you can do is reduce her stress by providing the right environment and making it easier for her to give birth. 

Strain From Constant Births

Since molly fish can store and use sperm after each birth, your molly can become pregnant again after every 28-30 days. The continuous birth process may put a strain on the fish. 

There should be a little break after each birth to let her gain strength. If she keeps reproducing non-stop, the strain may kill her.

Unfavorable Tank Conditions

The tank’s condition can affect the health of your molly fish, especially the pregnant ones. As mentioned earlier, pregnant balloon molly fish require a temperature of around 23-29 °C (73.4-84.2 °F) to stay warm and alive. 

They need clean water and good healthy food. They also need the right pH level and hardiness. That’s why it’s advisable to isolate a pregnant molly.

You can easily provide these necessities without affecting the other fish. If the tank falls short of these requirements, it can lead to sickness and even death of your pregnant molly.

Frequent Moving of the Molly

When a molly fish is pregnant, it’s advisable to move her to a new tank for her safety. However, you’ll have to move her back to the old tank after birth to prevent her from eating the fry.

Mollies give birth regularly. You’ll have to move them as often as they get pregnant. As necessary as it is, it can stress the fish. 

Frequent movement between tanks may cause your fish to die due to the stress.


Can Male Mollies Get Pregnant?

Male Mollies cannot get pregnant. Only female Mollies have the ability to carry and give birth to fry. Male Mollies play a crucial role in reproduction by fertilizing the eggs laid by females, but they do not undergo pregnancy themselves.

This means that if you only have male Mollies in your aquarium, you don’t need to worry about them becoming pregnant.

When Should I Separate a Pregnant Molly Fish?

Separating a pregnant Molly fish is important to ensure the safety of both the mother and the fry. It is best to separate her from the main tank when you notice signs that she is about to give birth, such as a square-shaped stomach or dark spots inside her abdomen.

By providing a separate breeding tank with clean and warm water, hiding spaces, and proper filtration, you can create an environment where she feels comfortable and secure during this crucial time.

Remember to monitor the gestation period, which can last at least 60 days, so you know when she is close to giving birth.

Is My Balloon Molly Bloated or Pregnant?

An enlarged and round abdomen is a clear sign that your Balloon Molly fish is pregnant. It may be easy to mistake this for bloating, but the shape of the stomach can help differentiate between the two.

If your Balloon Molly has a square-shaped stomach, chances are she’s pregnant. Keep an eye out for other signs like dark spots inside her abdomen, increased appetite, and possible aggression towards other fish in the tank.

Wrapping Up

Balloon molly fish are naturally bloated, so it may be difficult to tell when they’re pregnant. However, some signs indicate a pregnant Balloon Molly, including the following:

  • Square shaped abdomen
  • Ravenous appetite
  • The appearance of dark spots on their stomach
  • Behavioral changes like self-isolation, less physical activity, and reduced appetite when close to the delivery period.

When you notice these changes in your molly fish, isolate her in a separate tank. Providing proper care for her in a separate tank with clean water, hiding places, and adequate nutrition will ensure the health of both the mother and her fry.

Keep an eye out for any changes in behavior or physical signs to determine when she may be ready to give birth.

I’m Elle, the founder of FishHQ. I created this website to share knowledge, tips, and inspiration for beginner hobbyists to help them create a healthy, happy, and vibrant environment for their fish to thrive. Read more...