sexing tetra's

[kmlong]

Can anyone tell me how to sex tetra's? They are red tetra's(orangish in color and black fins). I have 3 of them right now but don't know the sexes. Also how about Rasbora's? thanks a lot

 

[webmoose]

many of the tetra's can be sex from the quick formula of the female is larger... Not sure about Rasbora's...