sexing mollies

Question
I have several molly fry and I know how the sex the adults (female has "fan" shape fin males have "stick" like fin...) when can you tell on the fry? I have 7 that are a little over 1 inch (almost 2 months) and several a little over a centimeter (less that a month) and 16 that are a day old. well thank you for taking your time to help me out.

(mollies are extremely prolific breeders if i separate the male how long will the female still have fry?)

Answer
Hi Amanda,

You should be able to differentiate the sex of the fry by the time they are 3 months. If you don't see any pointed anal fins, there's a possibility that they could be ALL females! Be patient, sometimes it takes longer for mollies to develop their gonopodium (the male's pointed fin).  It will be at least 2 months before you can tell on your newest fry.

If you separate the male, there's still a high chance that the female could become pregnant. This is because, for every mating, the female stores a bit of extra sperm. This means, that if a mature female has been kept with a mature male for one point in life, and then they are separated, the female can still give birth! (About 3 times, MAX), before having to fertilize again. If you have too much fry, you could always give them away to a friend.

I hope this helps, and Happy Fishkeeping!