Baby gubbies

[Sink or Swim]

I have about 20 - 30 baby gubbies at 4 weeks old. I would assume they are a mixture of both sexes but they all look females. Is this possible? how can the males be idendified?

 

[Aquagurl]

u cant realli tell wen they r small
but wen they get a lil bigger their colourin should differ and females will b larger

good luck tellin them apart