Platy fry sexing

[monaro_gto]

ok guys so I tank bred 5 sunburst platies and at 5 months i decided I didnt want any more fry so I would split them up. I took the two males out and let the 3 girls alone. I then moved the 3 girls to a bigger tank and a week later I look in and there are two females and 1 male.

Did i screw up? I dont really think I did, at 5 months old is there sex really locked in? I know there are fish out there that can change there sex can young platies do the same?

[henningc]

Once they are that old, yes their sex is already determined. Actually from birth on it is. Some males are late bloomers. Check the anal fin, if it is pointed at 4 weeks, it is a male, if round female.

[Michael Bailey]

What about mollies? I've had a batch of Dalmatians for about a month and a half ( fourteen total fry) and I can't see a gonopodium on any. Is it just possible I got all girls? I don't think it's probable, but I don't know everything.. :-/

[Mattyfelts]

the easiest way to sex them, as far as i know from breeding, is the anal fin! girls look like the have a triangle which is attatched to them. the males look like the have a pin coming out

[Michael Bailey]

Do you know the approximate age at which the differences in fins appear?

[Mattyfelts]

Originally Posted by Michael Bailey

Do you know the approximate age at which the differences in fins appear?

mine were like 1-2 weeks. As soon as I could see them basically maybe a month

[Michael Bailey]

Okay thanks! I'm going to check all of them more carefully. I can't possibly have ALL females.

[Mattyfelts]

Originally Posted by Michael Bailey

Okay thanks! I'm going to check all of them more carefully. I can't possibly have ALL females.

tbh I rarely get males

[Ian086]

Originally Posted by Michael Bailey

Do you know the approximate age at which the differences in fins appear?

Males have a gonopodium(penis). This can take up to three months to appear. Until them, they can all look like females. You should definitely be able to tell at 5 months. This applies to ALL livebearers- Guppies, Platies, Mollies and Swordtails....