What Age Do Platys Sex?

  1. LondonFishKeeper

    LondonFishKeeper New Member Member

    Quick history: I had a very small tank (24L) in which I kept 3 sunset platy (2F, 1M). Needless to say, they mated and I didn't get the pregnant females out in time before they gave birth. So I now have 15 platy! The male died soon after, no sign of disease or distress, I believe he was just old as he was already adult size when I got him from my LFS. Everyone has since been moved to a 125L tank and they're doing well - obviously much happier in their larger home.

    Question: all the platy fry are growing well, but they all appear to be female. They're about 3 months old at the moment, is it safe to assume I have an all female tank now? I would rather not have them mating again, and with no signs of aggression between them, I'm happy to leave it as is. But I want to be vigilant if there's a chance there might be male among them and I just can't see the gonopodium until they get a bit bigger.
  2. FishFish221

    FishFish221 Well Known Member Member

    They start at 3-4 months (or when they reach about adult size), with the rare occasion being all female/male. The ones that gave birth will probably be pregnant again since platys can store sperm for 3-5 months.
  3. OP

    LondonFishKeeper New Member Member

    I'm keeping my eye on the female I assume gave birth, so far she doesn't look pregnant, but I'm keeping my eye on her belly, and of course for any new fry. As for the other platy, I'm not 100% sure she gave birth to any fry, she never showed signs of being pregnant, but I'm keeping my eye on her anyway.

    As much as I love my new additions, I don't want any more! :emoji_sweat_smile: Sounds like I've got another month or so to wait until the gonopodium starts to form. If I have males, I think I'll see if my LFS want them.