Any clue how to sex O. Lithobates?

[lucky777]

Trying to sex my O. Lithobates for someone interested in classified section.  The only way I know is by their colouration.  Also I read on a site a few minutes ago that I can't vent sex them to tell for sure.  Any clue how to do this? I have no clue myself.

[pegasus]

If your fish are not mature you will have difficulty in venting them, I know I can't. Most of my young females lithobates are skinnier than the males but that's not a sure bet.