How Long Are Molly Fish Pregnant For? Breeding Guide (FAQ)

Molly fish are a prevalent freshwater aquarium fish. They are easy to care for and come in a variety of colors. When it comes time to breed Molly fish, it’s essential to know How long are molly fish pregnant for, and what to do to ensure a healthy litter of fry.

This Molly fish care guide will cover all you need to know about breeding Molly fish. Plus, we’ll answer some frequently asked questions about this process. So read on for more information!

How Long Are Molly Fish Pregnant For?

How long does it take for molly fish to give birth? Molly fish giving birth usually takes between 4-6 weeks. You can expect your Molly to become increasingly plump and swollen as the fry develops inside her.

When molly fish is pregnant and it’s time for the fry to be born, your tropical fish will become active and swim around rapidly in circles. She will also make “popping” noises and release eggs as she swims.

It’s essential to keep an eye on your pregnant Molly during this time and make sure she is not overstressed or harassed by other fish in the main tank.

How Do I Know When My Pregnant Molly About to Give Birth?

A few key signs can indicate that your pregnant Molly fish is about to give birth. These include:

  • Swelling of the lower abdomen – This may be accompanied by decreased appetite and loss of interest in food.
  • A decrease in activity – Pregnant Mollies often become less active near the end of their pregnancy.
  • Nesting behavior – Expect your Molly to start building nests around her tank mates in preparation for giving birth.
  • Increased respiration rate – As labor approaches, you may notice your Molly is taking deeper breaths than usual.
  • Restlessness and agitation – Many pregnant Mollies will become restless and agitated in the hours leading up to birth.

By watching these signs, you can help ensure your Molly and her fry are safe and healthy during the birthing process.

What Should I Do When My Molly Gives Birth?

Once your Molly has given birth, it’s essential to take some steps to ensure the safety of her fry.

This includes removing any other fish in the tank that may try to eat the fry, ensuring plenty of covers for the fry to hide in, and performing regular water changes.

You’ll also need to ensure that your Molly’s tank is well-oxygenated and the water temperature is between 74-80 degrees Fahrenheit. This will help to ensure that your fry is healthy and thriving.

How Often Do Molly Fish Have Babies?

Molly fish give birth every 30 days, depending on environmental conditions and other factors.

Molly fish are livebearers, meaning they give birth to live young. The female Molly fish will release her eggs into the water, and the male fish will fertilize them.

The eggs will then hatch, and the baby fish will be born.

Most Molly fish give birth to several hundred babies at a time. Baby Mollies can take care of themselves right away and do not need help from their parents.

By providing your Molly with the proper care and a stress-free environment, you can help ensure that she is ready to breed again shortly.

Molly Pregnancy Stages

Molly fish are a popular pet, and many people enjoy breeding them. As with most fish, the pregnant female Molly will lay eggs, and the eggs will hatch into fry. The entire process, from conception to hatching, takes about 28 days.

The first stage of pregnancy is known as the lag phase. During this time, the female molly stores sperm deposited in her reproductive tract close to the anal vent during mating.

About two days after fertilization, the embryo begins to develop. This development continues until day six or seven of gestation, when implantation occurs. 

The second stage of pregnancy is called the embryonic stage. During this time, the embryos grow and develop rapidly. They reach a length of 0.5 millimeters by day ten of pregnancy. 

The third stage occurs from day fifteen until birth and is known as the fetal stage. During this time, their body structures and organs continue to develop. By day twenty-eight, the fry is ready for birth. 

What Do Mollies Do When Giving Birth?

Molly females give birth to live young ones. So, how many babies? The Molly own babies are born encased in a mucous membrane, and they instinctively know how to find the water’s surface where they can take their first breaths of air.

The process of giving birth usually lasts for about 20 minutes, and during this time, the mother molly will often circle her young ones, fanning them with her fins to ensure that they get enough oxygen.

When a molly is ready to give birth, she usually seeks out a sheltered area where she feels safe. She may take shelter under rocks or plants or find a small cave to hide in.

Once she is ready to give birth, Molly will lay her eggs in the water. The fry will be born within a few minutes, and she will take no further part in their care.

The fry can swim and feed soon after being born, so you don’t need to worry about helping them out. However, it is crucial to provide them with plenty of hiding places to help keep them safe from predators.

To ensure the best outcome for your adult mollies and their fry, it’s essential to observe them for signs of pregnancy and be prepared when the time comes.

Are Molly Fish Easy to Breed?

Yes, Molly fish are easy to breed. They are considered one of the easiest fish to breed. They typically spawn without any problems and will readily take care of their young.

To ensure a successful breeding experience, you must provide your mollies with the right environment. This means setting up an aquarium specifically for breeding and providing your mollies with the proper diet.

You also need to remove the male and female mollies and any aggressive fish from the tank, as these can cause stress to your breeding mollies and affect their reproduction.

If you provide the right conditions for breeding, you should have no problem successfully breeding Molly fish. Just be prepared for the fry to hatch, and ensure you are ready to provide them with a safe and healthy environment.

Molly Fish Breeding time

Molly fish breed during late winter and early spring. The gestation period is about 28 days, and the fry (baby fry fish) are born in groups of 10-100.

The molly fry can feed on its own within a few days after birth and reach sexual maturity within a few months.

Molly fish breeding time is sometimes predictable, but when you understand Molly’s biology and provide them with ideal conditions and proper care, breeding should be successful.

Your mollies can be ready to breed again with patience and the right conditions.

How to Breed Molly Fish Fast?

Breeding Molly Fish can be a fun and rewarding experience, but it’s important to do your research before getting started. 

There is a lot of information on how to breed Molly Fish, but it can take a lot of work to know where to start. 

In this video, Danny provides simple and easy-to-follow advice on how to breed Molly Fish quickly and easily. You’ll learn anything you need to know about caring for Molly Fish, from setting up the tank to feeding them correctly.

How Can You Tell If Mollies Are Pregnant? (Molly Fish Pregnant Signs)

If you’re wondering how to tell if mollies are pregnant, there are a few signs you can look for.

  • First of all, pregnant mollies will often become less active and spend more time hiding or resting in the corners of the tank.
  • You may also notice that the female’s abdomen looks swollen or her scales appear more prominent than usual.
  • When a molly is about to give birth, it’s common for them to eat less and appear nervous or agitated.

If you notice any of these signs, it could mean that your mollies are pregnant and ready to give birth. Observing your fish is the best way to determine if they are expecting fry.

What Does a Molly Fish Look Like Pregnant?

Many think a pregnant Molly fish looks like she’s been carrying twins. However, the most noticeable change in Molly when she’s pregnant is her belly.

It becomes thicker and more square as opposed to the standard teardrop shape. This is because Molly fish have an egg-shaped uterus, and as the eggs grow, so does the belly.

The pregnant Molly’s belly will also become more colorful, and you may notice a dark spot in the center of the rounded belly. This is normal and indicates that the eggs are developing correctly.

Overall, a pregnant Molly fish will look bigger and rounder than usual. It’s important to provide her with a comfortable and well-maintained environment so she can give birth safely.

Should I Separate Pregnant Molly?

Yes, you should separate pregnant mollies. It’s essential to provide them with a comfortable and stress-free environment so they can give birth in peace.

Plus, if there are other fish in the tank, the pregnant fish may become shy and hide from them, making it difficult for her to give birth.

When to Put Pregnant Molly in Breeding Box?

When to separate pregnant Molly? As soon as the fish shows signs of pregnancy, it should be placed in its separate tank. The breeding tank should have a fine gravel bottom and ample spawning mops or plants.

The fish tank water should be soft and acidic with a pH of 6.0 to 7.5. The fish tank should also be heated to 78-80 degrees F (25-27 degrees C).

Most breeders prefer to remove the male Molly from the aquarium after the female fish has been successfully bred to prevent him from eating the eggs.

Collection of the eggs is generally done daily but can be done less often if good quality water is maintained in the breeding tank.

How Do You Know When a Fish Is About to Give Birth?

The pregnant fish’s bulge becomes more visible below her gills as she develops a squarish outline. The gravid spot has also enlarged, becoming larger than before and taking up much of its space in other body parts.

The couple can watch their new arrival grow inside their mother’s belly!

How Long Are Black Mollies Fish Pregnant?

The average gestation period for black mollies fish is about 20 to 40 days. However, the duration of pregnancy can vary depending on the species, water temperature, and other environmental conditions. And it may take up to 60 days.

It’s also important to note that molly female can store sperm for later fertilization to become pregnant multiple times in a row.

Black Molly Pregnancy Stages

Unlike other fish, black mollies undergo a process called “live-bearing,” which means that the young are born alive and not from eggs. Black mollies have a gestation period of about 28 days.

The female mollies will first release their eggs, and then the male mollies will fertilize them. The embryos will then develop and attach themselves to the inside of the mother’s uterus.

At around day 10-12 of gestation, you may see signs that your Molly is pregnant, such as increased activity, lack of appetite, and lighter-colored mollies’ changes in color.

The fry (baby fish) will be born fully formed and free swimming. They will be able to eat solid food from birth and should be removed from the parents’ fish tank as soon as possible to avoid being eaten.

  • The first stage of pregnancy in black mollies is called the resting stage, during which the female’s body prepares for egg production. During this time, the female Molly’s abdomen becomes visibly more prominent, and her scales may appear thicker than average.
  • The second stage is when the eggs are fertilized and begin to develop. During this stage, the female’s abdomen becomes noticeably swollen, and her coloration may become more vibrant or intense.
  • The third stage is when the eggs are ready to be laid. The female Molly will become restless and start looking for a safe spot in the fish tank to lay her eggs.
  • The last stage is the birth of live molly fry, which usually takes anywhere from 1-2 days, depending on the number of fertilized eggs. After the fry is born, they will begin to swim and feed on baby brine shrimp and powdered fry food.

Once the fry is born, the mother, molly, will typically recover within a few days and be able to return to her usual activities.

Commonly Asked Questions about Molly Pregnancy and Breeding (FAQ)

How Long Do Fish Stay Pregnant?

How long are fish pregnant for? The gestation period of fish varies depending on the species, water temperature, and other environmental conditions. Generally, most fish carry their eggs for an average of 20 to 40 days.

How Long Does a Molly Fish Stay Pregnant?

The typical gestation period for mollies is about 28 days. However, this can vary depending on the species, water temperature, and other environmental conditions.

Do Mollies Reproduce Easily?

Yes, mollies are relatively easy to breed in aquariums. They have a live-bearing form of reproduction, meaning they give birth to fully-formed molly fry. For successful breeding to occur, the water temperature and other environmental conditions in the aquarium must be optimal.

Why Is My Pregnant Molly Shaking?

It is usual for a pregnant molly fish to shake or jerk, especially during the early stages of pregnancy. This is because the unborn fry is beginning to move around in the mother’s uterus and are pressing against her body, causing her to jerk or shake.

How Long Does a Molly Labour Last?

The labor of a molly usually lasts between 12 to 36 hours. And it is usually complete before the entire clutch of molly fry has been laid. The female Molly will rest for a few days afterward before returning to normal activities.

How Long Does It Take for a Molly to Give Birth?

It typically takes 1-2 days for a molly to give birth. The time can vary depending on the number of fries that were laid.

How Long Are Balloon Mollies Pregnant For?

The typical gestation period for balloon mollies is about 28 days, although this can vary depending on the species, water aquarium temperature, and other environmental conditions.


So, how long are molly fish pregnant for? Most fish species gestate their young for a period ranging from days to months. However, live-bearing fish like mollies give birth to a relatively large and well-developed fry that can fend for themselves immediately after birth. If you’re interested in breeding molly fish, it’s essential to understand the pregnancy cycle to provide the best possible care for your male and female mollies. And ensure successful spawning. Thanks for reading “how long are molly fish pregnant for” Blog post!

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About Me

I am the founder of, a devoted wife and mother, and an avid fish enthusiast. My aim is to assist fellow fish lovers worldwide in understanding how to properly care for and breed their pet fish.

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