Ok I still consider myself new at this, I have had an aquarium for 3 years but can't keep the water straight-still working out kinks, I guess. But I stick with Mollies b/c i love the many colors they come in and the fact that they are livebearers and my kids get to see the babies. ANYWAY, I had 4 female and 1 male in a small 30 gal. (one day I am goign to get good enough to have a huge 100 gal) anyway, 2 females died and then I thought the 2 females were PG b/c they both got extended bellies. Then after the poor male had "bred" himself to death I was left with just 2 Females. One had 15 babies and the other never did have babies. So then the other morning I am looking at the female who didn't give birth and her anal fin is now like a male's! I have watched her for 2 days to see if I am just not seeing her fold it or something but no she is definitely like the male's. Mollies are pretty easy to sex so I know what I used to have. All of that said, can they repeoduce if they change sex? This is a new one for me, I only thought frogs did that!