Decided To Try To Sex My Fry

[black molly3]

my fry are 3 weeks old today (or 4 i cant remember) and i deided to try to sex them.
out of 7 fry from 2 different mothers i have 2 males. i can tell what babies came from what mum now because they are developing the same colors as them.
my question is when will the males dvelop their geonopolium (sp) and when will they begin to grow nice colourfuller tails. the are still rather small but quite fat abut 2cm in length.
thanks

 

[OldMan47]

Remembering way back to the last time I raised mollies, I think you will be able to sex them at about 3 cm. At 2 cm they almost all will look like females.
Right now I have about 30 that are 1 1/2 to 2 cm so I'm waiting to find out myself. These are my first molly fry in about 8 or 10 years so the memory of when I could sex them has faded some.