Sexing Platy Fry

[Jen]

From the looks of it, all my fry (about a month old) are female. They all have the fan shaped anal fin. Is this common... to only get one gender from at least 3 different birthings? Do they change gender as they age???

Thanks

 

[breezer40]

I would give them a bit longer before you decide what sex they are. Mine are nearly 2 months now and a little easier to sex.

 

[HeatherSweetness]

I can never sex my platy babies for about 4 or 5 months. They take so long to show it.

 

[convict cichlid]

like every one else said it will take some time before the males machure enough to be sexed. hang in there and keep looking.

 

[ADelphi]

Interesting but will they start breeding or can they breed at that young age, i think you really need to be able to sex and seperate as soon as possible but it is hard, i've managed at 6 1/2 weeks old, but i still wonder if some of the females will turn male as the fin recedes. Mine are 3cm's now at 6 1/2 weeks and the boys seem bigger than the girls.

 

[Ddraig Goch]

Platys can breed at 3 months old, but males must have developed a gonopodium before they can reproduce. Once the gonopodium has developed they are easy to sex, they must then be separated immediately to avoid inbreeding. If young females are in a tank with developed males they will get pregnant at 3 months.

A month old is quite young to be able to sex them, you will have a better idea at 3 to 6 months, (a little earlier once you get used to it), I've seen males develop a gonopodium at 1 year so you must keep a close eye on them until you are sure.

Mature females will develop a gravid patch but this can be more difficult to see on some colours, on blacks or tuxedos it can be impossible.