How Old Before You Can Sex Platty

[RobGoldsmith]

My two platty fry are three months old now, they both have the back under fins as you would expect from females.

Will this mean they are both female or will that change and look more long and pointed as they get older? as you would expect from a males reproductive area

Thanks
Rob

 

[amy1994]

Depends what are you feeding them? Mine took 5months i think, maybe more, it also depends on the fish
heres some of my fry probably about a month or so...

heres them now...i think about 8months old

all of those swordtails i know that they are female, but strangely i only have 1 male ...

 

[helterskelter]

Both swordtail's and platies can take a very long time to fully mature.

Males can sex out from about 2-3 months of age, but I've also seen them take almost a year for the last of the males to fully mature.
The late developing males are always the best of the batch

 

[RobGoldsmith]

Thanks for the in depth replies