Can Mollies Have Babies Without Males? [3 Vet advice]

If you are into fish, you probably already know this, but for those who do not, mollies are a top choice for aquarists for a bunch of reasons. They are super easy to take care of, they come in a ton of different colors and patterns, mollies are generally friendly little dudes, and they are adaptable to a lot of different environments.

But there is another reason why mollies are so popular, and that is because they are absolute breeding machines. Seriously, these little guys are like the rabbits of the fish world. They can pop out dozens (sometimes even hundreds!) of fry every month.

Now, here is where things get interesting. A lot of people wonder if mollies can reproduce without male fish.

Can Mollies Have Babies Without Males

Can Mollies Have Babies Without Males? The answer is yes, they can. Mollies can actually impregnate themselves. It is not with their own sperm, though, but with the sperm of males they have mated with before. They are part of this group of animals called “sperm hoarders.”

It’s not super common, but it does happen and is pretty cool. Scientists aren’t exactly sure how or why this happens. Still, it’s thought to be a survival mechanism that allows female mollies to continue reproducing even if there aren’t any males around.

Table of Contents

Female Molly Just Had Babies without Male

If you’re a fish enthusiast, you have probably seen a bunch of posts online about some weird stuff happening in female-only molly tanks. Apparently, some of these female mollies can stay pregnant and give birth to babies even if they have not seen a male molly fish in months.

This has caused confusion and wild theories about mollies being able to change sex or self-inseminate (which would be pretty insane, right?). But the truth is way more interesting than that.

It turns out mollies are what scientists call “sperm hoarders.” 

This means that when a female molly mates with a male, she can store his sperm inside her body for later use. Her body even feeds the little sperm guys with sugar to keep them alive and kicking for longer periods of time.

So if a female molly has mated with a male in the past, she can use that stored sperm to fertilize her own eggs and give birth to babies without needing a male around. It’s kind of like magic, except it is just science doing its thing. 

And mollies are not the only animals that do this; there are some flies, rattlesnakes, and even chickens that are sperm hoarders too. Who knew?

Female Molly Just Had Babies without Male

So you have a tank full of female mollies, and you think everything is fine and dandy. But then you notice something strange: some of your mollies are pregnant, even though no male fish is around.

Well, as it turns out, those mollies probably mated with male fish before you bought them. When a female molly mates with a male, she can store his sperm inside her body for later use. 

And by later, we mean months later. Female mollies can keep that sperm alive and well for a surprisingly long time.

So even if no male mollies are in your tank, your female mollies can still get pregnant using that stored sperm. It’s like a little fishy time capsule, and it can lead to some pretty weird situations.

Scientists are still trying to figure out why mollies evolved to do this. On the one hand, it makes sense male mollies tend to have shorter lifespans than females, so storing sperm from genetically superior males allows females to produce healthy offspring even after the males have died.

But on the other hand, female mollies will sometimes use their stored sperm instead of mating with perfectly healthy males right in front of them. Why? Nobody knows for sure. And it is not clear whether the stored sperm degrades over time or not.

So there you have it, mollies are just full of surprises. But one thing is for sure; those little fish are pretty darn fascinating.

How to tell if Molly is Pregnant?

tiny fish tank

How Long Can Female Mollies Store Sperm?

Some mollies can keep that sperm alive and kicking for up to 8 months. But others might run out of stored sperm after just three months. What gives?

How Long Can Female Mollies Store Sperm

It seems like it might depend on where the mollies came from. Mollies that grow up in areas with fewer males might be more likely to hold onto that sperm for long periods of time, since it’s not always easy to find a mate. 

But if a molly comes from a male-rich environment, it might not bother to store sperm for as long since plenty of fish is in the tank.

Why are my mollies not breeding?

tiny fish tank

Either way, it’s clear that female mollies are the ones in charge when it comes to sex in the molly world. They’re the ones storing and choosing when and where to use that sperm. 

And honestly, who can blame them? It’s good to have a little control over your reproductive choices, even if you are just a tiny fish.

Do Female Mollies Die After Giving Birth?

No. Female mollies don’t usually die after giving birth, only in rare cases where complications arise. Female mollies are some of the most prolific breeders, and if you give them a comfortable and stable environment with the proper diet, they can produce offspring every month throughout their lives.

Mollies can live up to 1.5 to 5 years in good condition so that a single female can produce thousands of fry. 

If you have a mixed population of mollies, the more females you have, the more fry you can expect each month. Even in female-only tanks, the chances of molly pregnancy are still possible, although less likely.


Mollies can give birth to Babies without male mollies. Also, they can reproduce fries several times. So it would be best if you did not wonder when you get molly fries in the tank, even no single male mollies.

Related Articles: –

Why Is My Molly Turning White?

Similar Posts