How Fast Do Mollies Breed?

[jnms]

I recently swapped my fish stock and now have 15 Mollies in a 200 litre tank. I know these guys are likely to breed fast, but just how fast will they breed?

 

[Ludwig Venter]

This will depend entirely on your temperature jnms..... but if it is in the region of 26 to 28 deg C, you can expect every female to deliver between 25 to (around) 80 fry (depending on the size of the female) every 27 to 29 days.

Mollies are also less prone to eat their own fry (compared to Guppies, Platies or Swords), so you can expect a high percentage survival rate..... (you do however need to provide some floating plants for the first batch to hide in), but the subsequent batches are less likely to be eaten.... if there sre still fry of the previous batch swimming around with the adults.

 

[jnms]

Thanks Ludwig. This time of the year it's pretty much impossible to keep the tank below 26C. I actually left the heater switched off for 4 days without realizing it, and the temp never even got to 25C in that time. So it looks like the Mollies will end up having a lot of fry.

The tank isn't very heavily planted, so I will have to see how many of them actually survive. The fish are well fed, so maybe they won't go after the fry much?

That said, I don't want to end up with hundreds of fry in the tank...but I would like to keep a few.

 

[OldMan47]

If you want to control numbers on livebearers in general, I find it works best to sell off the mature adults, not the fry. Even so, you can become over run with fish if you are not careful.

 

[alysonpeaches]

Its difficult to be exact, but do you know how many males and how many females you have? In a community tank which is heavily planted I have a pair of mollies and the female drops regularly, every month to 6 weeks. As females mature they drop more fry. There are always fry swimming about, but only the odd one or two survive to adulthood. I have no idea if it is my platys or guppies which predate the fry, but I have just isolated some fry in a netbreeder because I want to increase my stocks of white mollies. I have been feeding the fry more frequently than the adults. The survival rate is heavily dependent on available food stuffs, but obviously you have to watch water quality if you feed more abundantly.

What I would say is, yes they will multiply but it will take a while to get overrun. Whilst you do read about drops of 50 plus fry, I dont see this many swimming about. You probably need to be prepared to move some on at some point or get another tank, but it will take a while.

 

[jnms]

Ok great, thanks for all the replies!

Will have to see how it goes. I'm not entirely sure of the male to female ratio, but there are certainly more females there.