How Long Is Molly Pregnant? Gestational Period And Care!!

Molly fish are beautiful fish with vibrant and colorful body structures that make them popular among aquarium enthusiasts. In addition, these fish are incredibly hardy and adaptable, making them one of the top choices for beginner aquarists. Since these fish are trendy, many fish breeders have an interest in breeding them. So, fish owners are now more interested in questions like how long does Molly fish stay pregnant?

Molly fish will be pregnant for almost 20 to 60 days, depending on the Molly fish’s age and health. These fish will show no signs of their pregnancy until the day they give birth. Molly fish will release small batches, and sometimes even a single fry at the time after giving birth.

Today, we will discuss Molly fish’s pregnancy and how long Molly stays pregnant.

What Is Molly Fish?

Molly is a freshwater fish that belongs to the Poecilia family, which originates in the southeastern United States. They have unique attributes that make Molly fish a particular pet.

There are several varieties of Molly species that include short-finned Molly, lyretail Molly, and sailfin mollies. In addition, there are different types of Molly available in the market: black molly fish, blueberry molly fish, butterfly molly fish, Dalmatian Molly Fish, and more.

Molly is one of the most popular aquarium fishes with unique features that make them excellent for home aquariums. Most people prefer Molly because they are small, easy to care for, do not require large tanks or ponds, live as single entities or in groups, and are peaceful.

How Do Molly Fish Reproduce?

Molly fish are live-bearing fish, which means the female Molly will give birth to baby Mollies. Molly can have multiple batches of babies at one time (up to 100). Unfortunately, they only live for about five years and do not take care of their young.

The eggs of a Molly fish are black, and a cluster of them attaches to the hair-like growth on Molly’s abdomen. The female Molly can have thousands of babies at one time. But very few survive due to competition for food and predators.

How Long Is Molly Fish Pregnant?

The time frame of pregnancy is the gestation period. Usually,  Mollies will be pregnant for about 60 days. But, on average, it takes about 26 – 32 days for Molly Fish to become pregnant.

Molly fish reach sexual maturity when they are about two inches long and have babies at around three months old. In a Molly breeding tank, the female will release eggs every other day until she releases 40 to 100 eggs in total.

Molly pregnancy occurs in stages:

It takes place for four to six days. Then, Molly fish will expel the eggs into an area of clean water and then fertilize them with sperm released by the male Molly fish.

If you notice that your Molly is carrying a small bump on its belly, it means she’s pregnant. Pregnancy in Molly Fish is visible very early because pregnant mollies will have a bulged tummy, unlike the normal ones.

However, you notice that Molly will start to produce large amounts of eggs at the later stage of pregnancy. As soon as Molly starts growing eggs at an accelerated rate, she will stop eating because she will become preoccupied with the process of pregnancy.

Breeding Process Of Molly Fish

Molly fish is a livebearer, and they give birth to babies. Molly gives birth after 21 days of fertilization or gestation period. The size of the litter depends on Molly’s age, health state, and nutrition levels. Maximum Molly can give birth to about 40-100 baby mollies.

But we need to ensure that their environment has enough food and space to accommodate their population. If Molly is under stress, she will not get pregnant, and her babies might die in the early stage of development. However, the number varies with Molly’s size, age, health condition, etc.

Molly fish breeding is not that difficult, especially if you have a Molly aquarium with a filter and heater.

How To Know Molly Fish Is Pregnant?

Molly fish are livebearers, which means they give birth to their young instead of laying eggs. The gestation period of Molly fish is usually around 28-38 days, but it all depends on the water temperature and environment.

If you have a female Molly who has just given birth to her fry, she will need special care. Molly pregnancy symptoms are:

  • swollen belly
  • reddened eyes
  • increased coloration
  • restlessness and lethargy

How To Take Care Of Pregnant Molly Fish?

Molly fish is one of the most popular freshwater aquarium fishes. However, Molly Pregnancy can be tricky to manage, and you need to make sure Molly Pregnant Fish is healthy for the babies to be born healthy.

Provide Enough Space For Pregnant Molly Fish

A pregnant Molly fish needs ample enough space for Molly to move around comfortably. In addition, Molly fish needs more room to swim in pregnancy. Mollies usually swim around for nesting and to find safe places for laying eggs. Thus, a crowded place will threaten them, and they will feel stressed and anxious. 

Provide The Right Water Temperature For Pregnant Molly Fish

Water temperature plays a vital role in Molly Fish Pregnancy. You should keep them at a specific temperature for their eggs not to die before they’re born and for the baby Mollies to stay healthy.

Give Molly The Right Food For Pregnant Molly Fish

Molly pregnant fish need more nutrients than typical Molly, so make sure you feed Molly more often with food. Also, pregnant fish food is very different than regular Molly fish food. So make sure Molly gets the correct type of food to stay healthy and strong enough for pregnancy.

Maintain Water Quality For Pregnant Molly Fish

Don’t forget to maintain good water quality for Molly since that is very important during pregnancy. Again, frequent water changes are the key here, so make sure you change about 50% of the water once a week.

Maintain The Right pH Level For Molly Pregnant Fish

Last but not least, make sure Molly gets the right pH level in the aquarium since it also plays an essential role during pregnancy. Having the right water chemistry will ensure that Molly stays healthy and robust enough and lives longer.

Some FAQs

How Much Food Do Pregnant Molly Fish Need?

It would help if you gave pregnant Mollies a variety of diets, including meaty foods and algae.

It is best to feed Molly small amounts of food several times per day instead of one large feeding. It will keep the water quality high for a healthy growth environment. When Molly fish are pregnant, they need even more nutritious food than usual because their energy requirements increase.

In addition, Molly fish become more active during their gestation period, so they need a diet rich in protein and fatty acids to support this increased activity level.

How Many Fry Do Pregnant Molly Fish Produce?

Molly fish are capable of producing up to 300 fry for their two-year lifespan. They can reproduce every four to six weeks, but they produce more offspring during spring and summer months when water temperatures are highest (between 68°F/20°C and 80°F/27.78°C).

Molly fish typically give birth between 12 hours and three days after fertilization. They give birth in a 100-200 fry group, and they do not care for their offspring once they are born.

How Many Times Do Molly Fish Get Pregnant In Their Lifetime?

Molly fish are capable of getting pregnant multiple times throughout their lives. They typically live for around two years, but they can live as long as five years under optimal conditions. These fish normally only reproduce once during their lifetime, but they can give birth significantly in some cases.

Molly fish can reproduce year-round, but they typically mate during the fall and winter when water temperatures are more relaxed. They will typically give birth within 48 hours after fertilization, and they do not care for the fry once they are born.

How Long Does It Take Molly Fish To Get Pregnant?

It takes Molly about four months to get pregnant after reaching sexual maturity. It is because mollies have had eggs ever since their birth. So their gestation period depends on how often Molly fish mate and fertilizes those eggs.


In conclusion, Molly stays pregnant for about four months. Molly fish are compassionate creatures. So it’s important not to rush the pregnancy or put Molly under any stress. Molly fish are well-known for not being picky eaters, so Molly should have no problem getting the nutrients she needs to grow healthy fry.

Hopefully, this blog post gave you an insight into Molly fish’s pregnancies. For more information, feel free to contact us.

Keep breeding your Molly fish.

Thank you.