Gender Differences

[random919]

How do you tell the gender of:
Neon Tetras
Black Tetras
Rummy Nose Tetras

I have 4 rummy nose tetras in my tank and my nan has 1 neon(going to get more next week, some just died) and 5 black tetras.
thanks
random919

 

[KittyKat]

The gender of the fish does not matter for when you get the new fish. I do strongly recommend that, if the tank will take it, you aim to increase each school up to 10 fish or even more, which is especially important for the rummy nose teteras.

Adult females are fuller, rounder and larger, while males are slender.