Does Molly Fish Give Birth All At Once?

If you are already a skilled aquarist in raising Molly fish, then you might be fit for knowing about the next level now, i.e., understanding everything related to their breeding. Concerning the breeding, you may wonder specifically, if like other fish species, does Molly fish give birth all at once or not?

So, ‘Does Molly fish give birth all at once?’ Yes, Molly fish gives birth to all baby fries at once. A female Molly fish usually can give birth to around a hundred baby Mollies at a point. They generally have a high ability to give birth to all baby Mollies at once. 

Molly Fish Breeding

Molly fish are the livebearing fish. Meaning, they don’t lay eggs but fertilize their younger ones and gives birth to them directly.

For breeding Mollies, you need not put in many high efforts. If both male and female Molly fish are in the same tank with a suitable tank setup, their breeding is possible without many struggles.

Go for at least 45 gallons of the tank if you plan to breed Mollies in the same tank where they stay. Besides, maintaining the tank temperature, water quality, and proper feeding of Mollies can boost breeding.

However, be careful to maintain a proper ratio of male and female Molly fish in a tank. Because generally, the male Mollies stresses the females by their constant pursuance. I would suggest you keep at least 3female Mollies and 1male Molly fish in a tank to dodge the case of stressful pursuing for mating.

Besides, in general, the female Mollies can store sperm from the males for an extended period after a single mating. It means she can give birth to many little Mollies even if there exist no male Mollies in a tank. Then, she carries the sperm and impregnates herself after a couple of weeks.

How To Identify If My Molly Fish Is Pregnant?

Identifying a pregnant Molly fish is not difficult if you observe them closely regularly.

After the mating, it will take a few weeks for the female Molly fish to give birth to little fries. In this interval, you will see some changes in her if she is pregnant. The differences arise in her physical appearance and also slightly in her behavior.

Some physical changes in a pregnant Molly fish are:

  • Swollen belly: The belly of a pregnant Molly fish gets swollen and looks more rounded than usual.
  • Variances in the shade: There is the visibility of a small black-colored pattern in the lower stomach of a pregnant Molly fish.

On the other hand, you can note that a pregnant Molly will socialize less with its tank mates and spends most of the time alone. Also, she mostly swims around the water heater placed zone and eats more than often.

By noting the physical and behavioral changes of female Mollies, you can identify if they are pregnant.

What Is The Gestation Period Of Molly Fish?

Here, I cannot fix a specific time as the gestation period varies for every Molly fish. But from my experience, I can assure 45 to 50 days on average as a gestation period of Mollies.

However, some Molly fish gestate babies for more than 50 days or 55 to 60 days. Such cases happen as the diet, tank environment, and lighting impact on the living of Mollies.

Don’t worry! Till you maintain a comfortable living for Mollies, any problem in their gestation period is uncertain.

Extra Cautious Is Necessary During Gestational Period. Know Why?

In the gestational phase, you should thoroughly keep your eyes on the pregnant Mollies. Because it is a period when the pregnant Mollies face much trouble as they get ill more often. Their tank mates and male Mollies mostly chase and bully them, which is unhealthy for them.

Hence, it is significant to set some hiding spots, which you can do by placing more live plants in a tank. It will make the pregnant Mollies comfortable and secure.

Yet, I would suggest you keep your pregnant Molly fish away from its tank mates in a separate tank to avoid any stress and pressure. Or, you can separate her from others, even in the same tank, by using a breeding net.

By the separation, she will feel secured, and there won’t be any trouble while giving birth. But be aware, the detachment should not be for a longer time. After the delivery, you must keep the female Molly fish together with its tank mates.

Birth Period Of Molly Fish

As stated above, the female Mollies usually store the sperm from males for a long time after a single mating. They then fertilize the eggs inside them and produces.

Later, after a couple of weeks, they give birth to their fries.

Is My Molly Fish About To Deliver Babies?

Like said before, there is no exact time to assure the specific birth period of Molly fish. However, many aquarists proclaim that a V-shaped form is visible around the lower stomach in female Molly if she is about to deliver babies.

Furthermore, a pregnant Molly fish stays away from everyones’ sight and looks for more hiding spots if she is about to give birth to baby Mollies.

Does Molly Fish Give Birth All At Once?

As the Molly fish are not large-sized, many people wonder if they give birth to many or a little at once. If you think alike, here is what you should learn!

A female Molly fish usually gives birth to all the fries at once. She seems too tiny to give birth to all at a time, but yes, it is a fact! The female Mollies generally produce multiple births, around 100 at once.

Here, don’t get confused as all the hatched eggs in an expecting Mollies are born at once. They can indeed store sperms from males for a long span. But once the fertilized eggs turn into fries, the pregnant Mollies give birth to all at once.

Besides, the Molly fish breeds quite regularly. So, you can expect a large number of fries to born when she gives birth.

Saving the Molly Fries

You can witness the birth of all fries at once.

But do you know the mother Molly fish can eat the fries too? Yes, you read it right!

There is a likelihood that the female Mollies can swallow the tiny Mollies after their birth. Not only mother Molly, but the rest of the adult fish in the aquarium can eat them.

So, separating the fries in another tank of at least 10 gallons is significant. Here, maintaining adequate lighting, warm temperature, and enough live plants is crucial for baby Mollies.

You can feed them some baby brine shrimp, micro worm, etc.

Later, keep the fries with other fish in their tank once the fries turn into adults. Until they fully turn adult, it is essential to separate them from other fish, including their mother, to keep them safe.


Molly fish are peaceful species that you can add to your aquarium. The beauty can add up if you want to witness them giving birth to little fries. Here, don’t be puzzled as they give birth to all little Mollies at once.

Be aware and keep more female Mollies and fewer male Mollies in a tank for breeding purposes to avoid female Mollies stress.

Also, make sure to care for the baby fries after their birth, as staying in the adult fish aquarium is unsafe for them.

Now that you know the Molly fish breeding phase, I am sure you would be an expert aquarist in sheltering them too.