Sexing Mollies

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Aquarium Advice Freak
Jan 18, 2010
Denver, Colorado
Is it possible to tell the difference between male and female mollies? My girl molly has had two batches of fry since January and I don't want her to be a breeding machine. Eight of her first batch have survived and are doing quite well. I would like to separate the males and females if possible, before I end up with eleventybillion mollies. Can anyone give me any direction in this? How old do the fry have to be before they can be sexed. Or can they be sexed at all?
yes its very easy to tell the difference between them, but you have to wait until their about a few months old and get big enough to see their equipment....the males have a thin anal fin, called a gonopodium and they will wiggle it around, the females, their anal fin fans out like a normal fish. their anal fin is the one that preceeds their tail fin and is very easy to see the difference if you can catch them sitting still.
why my large mollies not having babies?

I have two large sailfin mollies almost 4 inches long, one male & female. I also have a smaller male sailfin mollies. The large male, a gorgeous fish with a red head, never seems interested in chasing the female. The smaller male did much more chasing around. But I never see the female pregnant with babies. They are in a 55 gal community tank. Do I have to put them alone in a small tank (say 10 gal) before they will do their thingie and give me some babies? Any idea?
Mollies will procreate regardless of the number of fish in the tank with them. It is very possible that your fish are breeding, but the babies are being eaten before you get a chance to see them.
Mollies also store sperm in their bodies. If they've had babies once, they will continue to do so even if the female is kept alone.
a little off topic but i have 3 mollies 2 female, i got them bout a week ago planning on having babys is there any chance they could have paracites already when i brought them like worms or anything harmfull to feed to my oscar, and is there any way of knowing or am i just stressing, aslong as my tanks clean theyll be alright? or is there a way to find out or would i know?
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