How Long does it Take for a Molly to give Birth?

Among the most sought-after aquarium fish is the molly. They’re a great option for newbies since they’re easy to look after. Plus, they come in a variety of lovely patterns and colors.

Additionally, molly fish are quite simple to reproduce in a fish tank and are usually mature once acquired from a pet store. Mollies are gentle fishes that do well in bunches.

For this reason, knowing how long a molly gives birth is a crucial aspect that most aspiring fishkeepers must know.

Short Answer

Female mollies will give birth to their offspring after around 60 days of gestation. Furthermore, females can retain sperm over months and might even stimulate the fertilization of eggs as frequently as every month, even if there’s no male in the aquarium.

Mollies can release between 10 and 60 fry every birth. Mollies that seem to be younger or in their very first pregnancy usually have a lesser number of fry, instead of birthing more.

Long Answer

To explain further the birthing process of a molly fish, here’s what you need to know.


Internal fertilization is a molly’s reproduction process. The male molly implants the sperm once it’s inside the female molly. She retains it within her till the fry or young fishes are mature enough to release.

Gestation Period

To restate, female mollies have a gestation period of around 60 days. A mother molly can retain sperm for lengthy periods, allowing it to fertilize herself around every 30 days. Even yet, some mollies can gestate longer, like 50 to 70 days.

Molly Fry

To prevent the fry from being devoured by bigger fish in the tank, put the pregnant molly inside a breeding net shortly before giving birth. Withdraw her out from your breeding net once she has released the fry and leave it alone until they become bigger.

How Do You Know that a Molly is Pregnant?

There are physical indicators that your female molly is expecting offspring. Also, there are behavioral patterns that you need to know.

Physical Indicators

The stomach is shifting and being squared out. Mollies with round bellies are typical. However, when she is carrying her baby, her abdomen will be bulkier and more squared.

The belly will have noticeable black lines. When you have light-colored mollies, this is a wonderful indication. Black patches around the anal opening are also a reliable indicator that female molly is pregnant. These dark dots are the visible offspring.

Behavioral Pattern

The molly consumes more food than usual. This is more difficult to detect if you don’t know how often they consume regularly. Not everybody is sitting there watching exactly how much food their fish eats.

How Do You Know that Your Molly is About to Give Birth?

Once you notice these three behavioral indicators indicating the molly is about to deliver her offspring, it may be best to separate her.

  • She begins to swim not that much as before. Plus, she stays in one place for an extended time.
  • She begins to hide between plants or aquarium ornaments. She could even remain near the aquarium heater to keep warm.
  • On the contrary, during her pregnancy, where she eats more, she loses her appetite once she is due to deliver offspring. She may also get hostile against other fish.

Conclusion – How Long Does it Take for a Molly to Give Birth?

If you wish to reproduce your mollies, then you should keep the following guidelines in mind. Once you get to understand the mollies a little better, you’ll be able to tell whenever your female mollies are pregnant, as well as how to care for them. With all of these guidelines, you would have anything you need to keep your mollies healthy while they reproduce.


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