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Do Mollies Eat Their Babies?

With mollies being such great entry level fish to keep, many of the people new to the fish keeping hobby tend to start with mollies or other livebearers before progressing to other species of fish.

Once people have worked out how they are able to accurately sex their mollies, they often start to try breeding them so we do see a number of questions each month about breeding mollies and the various potential problems with breeding mollies.

The most common question that we see from the mollie owning community about breeding mollies is if mollies eat their babies or not.

Mollies are livebearers meaning that they give birth to live babies rather than spawn eggs so if you are looking to seriously breed you mollies, knowing the ins and outs of the mother’s chances of eating her babies, as well as any other mollies in the aquarium, eating the babies is important.

Unlike other fish species where you are able to just move the eggs into another body of water to hatch in safety, live babies are released into the water and can quickly become a snack for other fish in the tank.

This is why breeding mollies can be a little tricky for beginners as you often have to multiple aquariums and tanks available to transfer the baby mollies into as a way to prevent them from being eaten.

Do Mollies Eat Their Babies?

Mollies do eat baby mollies and a mother mollie can give birth to her own babies and then turn around and start eating them with this being surprisingly common.

Depending on how many mollies and other fish you have in your aquarium, a full pregnancy can be wasted due to the baby mollies quickly becoming snacks for the other fish in the aquarium.

This is when the majority of people who are trying to seriously breed their mollies will usually pick up a cheap cheap breeding tank for pregnant mollies to be moved into prior to giving birth.

Once the pregnant mollie gives birth, she will then be moved back to the main aquarium leaving the breeding tank as a safe haven for the baby mollies to live in without there being any potential predators to eat them.

Although it may take a couple of minutes for the mother mollie to turn round and decide that her babies look edible, this is a common problem with breeding all livebearing fish.

The majority of fish that lay eggs will have some form of protective instinct for their egg clutch but once their babies emerge from their eggs they are also often seen as fair game when it comes to the food chain, even by their parents.

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Why Do Mollies Eat Their Babies?

Mollies and other livebearers have no parental instinct to try and protect or even help their own babies and once the babies have been born, they are often seen as a potential food source by their parents.

This has always been the case with all species of livebearing fish but the exact reason that mollies eat their babies is not actually known.

Some people do suspect that it is due to the mollies not having a very good memory and this was the dominant belief for quiet some time but more recent research into the intelligence of fish and their memory capacity has proven this to be unlikely.

It is more likely that it is simply just survival instinct that wild mollies evolved with due to food not being as reliable as it is for a mollie kept in captivity.

Just because you know that your are going to provide your mollies with a steady food supply, ideally a high-quality fish food does not mean that your mollies know that they will be given this food.

Their instinct kicks in to eat their own babies and thus a pregnant mollie can give birth to her babies and then turn around and start eating any of them that are not quick enough to get into cover.

How Do You Prevent Mollies From Eating Their Babies?

The best option to prevent mollies from eating their babies is to get yourself a breeding tank and move your pregnant mollie into it.

Once she gives birth, move the mother back into your main aquarium and leave the baby mollies in the breeding tank until they are large enough to be moved back to your main aquarium or put into a suitable aquarium of their own.

Another option that is less effective is to try and make sure that your main aquarium has plenty of cover ranging from live plants, fake plants, and fish hideouts to provide the baby mollies with plenty of cover to hide from their tank mates that may try to eat them.

The natural instinct of a new born baby molly is to dive for cover as quickly as possible so making sure that there is plenty of it available in your aquarium can increase the survival rate of your baby mollies.

We often see people from the fish keeping hobby who try to breed their fish asking about if they should add fish fry hiding grass to their aquariums or not.

In our opinion, the options above tend to work just as well while also working out to be cheaper with some fish keepers thinking that fish fry hiding grass is a waste of time due to live plants and normal fake plants being more effective anyway.


That brings our article going over if mollies eat their babies or not to an end. We hope that we have been able to help you realize that even a mother mollie will turn round and start eating her babies if given a chance. Many people new to fish keeping who re trying to breed their mollies or other livebearing fish will make this mistake and end up with huge losses that are often easily avoidable with a little prior planning.