Sexing Young Bettas

[channing]

there is three bettas that im looking at but heres the catch. their are all young short finned. there were sold to the store as females but they are all blowing nests. now my one female blows little bubbles so the two im not worried about but the one is blowing nests like my males. they all have the white dot. if i get them they will be going in with my other female. so any thoughts would be great. i really dont want world war 3 or betta babies right now.

 

[Jaded12]

Males ten to have longer ventrals, a longer more defined anal fin, and a bigger "beard" when flaring. Do u have any pictures?