The dif.. between a baby male molly and a female molli

Question

how can i tell the df between a male molli and a female molli

will the fry (when they get older) breed with their siblings?

Answer 1

Yes they will breed with their sibling at the age of 6 months and they dont develop until 4 months i think..

Well the males have a long straight fin underneath and females have a big curved fin underneath.

Answer 2

Female livebearers have a fan-shaped anal fin (like a normal fin). Males have a long tube-like anal fin that they hold tight against their bodies. Siblings will breed together.