How Many Babies Do Mollies Have? Record-Breaking Number!

Dec 27, 2021

How Many Babies Do Mollies Have

Credits: Andreas (Creative Commons license)

It’s super easy to breed mollies. They’ll just about breed anywhere under any circumstances. These prolific breeders can overrun your tank with tiny fry in no time. So, how many babies do mollies have? 

Let’s find out! 

How Many Babies Do Mollies Have? 

Mollies have anywhere between 40-100 babies at one time. The number of babies they produce each time is dependent on factors like the mother’s age, size, health, and environment. 

The record for the highest number of babies a molly had in a year was 570. However, note that it was through multiple birth sessions. 

How Many Babies Do Black Mollies Have? 

black molly
Credits: Marrabbio (Creative Commons license)

The answer is the same as above: 40-100. The number of fry is mainly dependent on the size and age of your black molly. The older and bigger she is, the greater the number of fry will be. 

If your molly is big and healthy, it won’t be uncommon for her to deliver upwards of one hundred babies. 

How Many Babies Do Dalmatian Mollies Have?

Dalmatian molly
Credits: Corpse89 (Creative Commons license)

Like the rest of the molly types, dalmatian mollies can have 40-100 babies at a time. However, if it’s her first time, she will only give birth to 8-10 babies. 

As she matures and gains more experience, the number will gradually increase. 

Here are some answers shared by hobbyists on different forums! 

“The first time my dalmatian molly dropped her fry, there were only 8 or so. Only 1 survived – rest were eaten.”

“My molly just had 70+ overnight.”

“It depends on the size of the female. My molly is a good size, and she had around 40 babies.”

How Big Are Baby Mollies? 

Swordtail molly fry
Credits: Ltshears (Creative Commons license)

At birth, molly babies are about ¼” long. They’re fully developed by the time they’re born and look like miniature versions of adult mollies. 

And it takes around 4 to 6 months for the young molly fry to grow and reach their full size potential. 

Recommended Readings!

How Many Mollies In A 10-Gallon Tank? It’s Not Really Recommended!

How To Tell If A Molly Fish Is Dying? Look For These Signs!

How To Care For Pregnant Black Molly Fish?

Do Mollies Eat Their Babies? 

Yes, mollies eat their younglings. Therefore, you need to separate the fry from adults and even their own mother as soon as they’re born. 

Why Do Mollies Eat Their Babies?

Many fish, like krib cichlids, go to great lengths to ensure the survival of their offspring. But mollies eat their own babies. 

The reasons behind filial cannibalism are speculated to be weeding out weakling, a spill-over response caused by stress, and a means to replenish fat storage. 

What Do Baby Mollies Eat?

Baby mollies, about ¼” long at birth, are born ready to eat. Here’s a list of food they can safely consume:

  • Baby brine shrimp
  • Pulverized flakes
  • Hard-boiled egg yolk’s paste 
  • Daphnia
  • Microworms 

Although fully developed, molly fry have extremely tiny mouths. Therefore, you need to provide size-appropriate food they can easily fit inside their mouth. 

While pulverized flake food works just fine, here’s a link to a much-loved product – First Bites – by Hikari specifically designed to be fed to fry. 

This product is especially rich in protein to ensure the fry’s rapid growth. 

Hikari first bites

How Often To Feed Molly Fry?

Baby mollies should be fed several times a day – around 5-6 times – owing to their fast metabolism. As a matter of fact, molly fry are constantly hungry due to their fast digestion cycle. 

Ensure that you remove all the leftovers as soon as they’re done eating. 

Otherwise, the water will quickly brew harmful compounds like ammonia and nitrite that can be life-threatening for these poor little guys! 

How To Set Up A Tank For Molly Fry?

Molly fry should be raised separately from parents as they eat their own fry. You need to have a fully-cycled tank ready by the time the fry are born. Young fry find it challenging to find food in a big tank – so a 5-10 gallon tank, depending on the number of fry, should be enough. 

Equip the tank with a heater that maintains a stable temperature around 72-84 degrees Fahrenheit (23-28 degrees Celsius). Mollies are tropical fish – they like the water temperature to be warmer. 

If your heater doesn’t come with an inbuilt thermometer, you’ll need to buy one. 

Like a heater, a filter is indispensable too when setting up the fry tank. You must use a sponge filter so that it doesn’t suck in your tiny fry

If you don’t have a sponge filter, you can improvise using a pierce of mesh cloth or nylon. Just place the fabric on the top of the filter outlet and fasten it with a rubber band. 

I definitely don’t want to play you like a fiddle, but if you’re serious about raising fish fry, it’s best to invest in a reliable sponge filter. 

They don’t cost much – I swear! 

I’d suggest not to add any plants, decors, or substrate as they can single-handedly or collectively make it harder for fry to find food

If starved, the fry can drop like flies. So, leave the aesthetics for some other time. 

Is There An Alternative To A Tank For Molly Fry?

If it’s not possible for you to set up an entirely different tank for your molly fry, you can also use a breeding box. 

Here’s a link to one by Fluval that I use:

Fluval holding and breeding box

It hangs on the back and has a 0.5-gallon capacity. 

However, you shouldn’t keep your fry in a breeding box for too long as it can negatively impact their growth. They can live inside a breeding box for only about 2 weeks. 

Frequently Asked Questions 

Do Mollies Lay Eggs? 

No, mollies don’t lay eggs. They’re livebearers that give birth to free-swimming fry. However, mollies sometimes lay unfertilized or undeveloped eggs that they’ve either aborted or miscarried. 

These tiny eggs have a translucent yellow color. Under no circumstances will these eggs yield fry. Instead, they will develop fungus and rot away. 

If you want to read up on why mollies lay premature eggs, you wouldn’t want to give this article a miss. 

How Often Do Mollies Give Birth? 

Once sexually mature, mollies can give birth once every 30-45 days

How Long Does It Take For A Molly To Give Birth?

A molly’s gestation period lasts around 8 weeks (2 months). The entire process of pregnancy can be divided into 5 parts.”

  • Conception 
  • Formation of embryo 
  • Fry’s development 
  • Pre-birthing stage 
  • Birth 

If you are interested in knowing what happens in these stages and how long they last, don’t forget to check out this article

How To Tell Male And Female Molly Fry Apart?

You can tell a male and female molly fry apart by looking at their shape. Males usually have a more tapered, torpedo-like body, whereas females are broader. 

The colors on the males are also more intense, and they have longer, pointed fins than females. 

Final Words: How Many Babies Do Mollies Have?

Mollies have around 40-100 babies. However, from what I read on forums, the number of fry they give birth to is significantly less when they are new to motherhood.

Also, the size, age, health of the female, the environment they’re in, and the stress level play crucial roles in determining the size of the clutch. 

About ¼” long, the fry are born ready to fend for themselves since their own parents are the biggest threat to their lives. 

Recommended Readings!

Everything You Need To Know About Balloon Belly Molly

How Long Do Mollies Live? Extend Their Lifespan!

How Long Are Molly Fish Pregnant For? Twice As Long As Guppies!

What Do Molly Fish Eggs Look Like? Little Yellow Balls!

rohit gurung author at urbanfishkeeping

About Rohit Gurung

My never-ending love and fascination with Aquascaping started when I received a red-eared turtle for my 10th birthday.

Apart from researching and writing, I spend hours gazing at my 3 turtles. And yeah, I bask alongside them too.