Breeding Mollies – A Short Guide On The Ins-And-Outs

Construct Construction GIF from Construct GIFs

1. Let the fish mate 

Mollies are hierarchical fish, led by the male with the strongest colors and the largest fins. This means that the ideal is to have a single male and several females in the same aquarium. This is not only a good ratio for breeding mollies, it also keeps aggression and stress down. Mollies are very friendly to other fish but aggressive amongst themselves. The male mollies are worse offenders than their female counterparts.

During mating, you’ll see the males under the females. If copulation is successful, larvae will be born after three to five weeks.

2. Remove the female molly from the aquarium before she gives birth

If possible, put the female molly in a separate aquarium. Male mollies usually chase females to copulate more, which can make them stressed and impair pregnancy. To find out if a molly is pregnant, see if her belly is large.

If you cannot isolate the female molly in a separate aquarium, use a nurser tank. It basically consists of a plastic-edged cube with nets that protect the mother and larvae.

Do not wait too close to giving birth to get the female molly out of the aquarium. The chances of miscarriages and stillbirths are greatly increased when mollies are stressed.

3. Separate the female molly from the larvae

Female mollies also eat the larvae, so it’s best to take separate them. Don’t forget to do this at least once a month, since female mollies can retain fertilized eggs for up to six months. 

Extra breeding mollies tips

  • Most female mollies are already sold pregnant. 
  • The hardest part is separating larvae from hungry parents.
  • Use a sponge filter for larvae. This prevents them from being sucked into the filter.

How to care for the larvae (post breeding mollies)

Dory Finding Dory GIF from Dory GIFs

1. Feed them

You can feed larvae with microworms and small nematodes. Use the flake feeds (artificially processed thin layers of food), giving them in varied rations as they develop to fry. 

As they grow, there are several types of worms that are great for feeding Mollies, examples are microworms, blackworms, and bloodworms.

Frozen or live brine shrimp are also great sources of nutrients for adults and fry. 

If you can feed them algae, that’d also be great. Mollies normally eat algae in the wild.

Overall when it comes to feeding mollies, you will not encounter many problems. Mollies are oviparous animals, which means that these fish eat little. 

2. Let the larvae mature 

It’ll take about two months to differentiate between males and females. Once they have doubled in size, you can place them along with the other fish in the main aquarium.

Another great way to know if larvae can change aquariums is to see if they are already bigger than the mouths of other fish. 

3. Separate the males from females 

Once you’ve discovered the sex of the young fishes, take the necessary precautions so that they no longer reproduce until when you want them to. Brothers and sisters usually cross each other. Breeding mollies can create colorful new offspring, but inter-family larvae will be more susceptible to defects and diseases. It’s best to be safe and separate males and females before they are eight weeks old, which is when a molly reaches sexual maturity.

Hope this helps in multiplying the amount of mollies in your tank! If you’d like to learn more about caring for your molly, check out this article.