Can you sex the RES by looking at them?
I am pretty sure that I can, I would have to pull them out and get a good look at them individually to be sure, anything over 5" should be easy to sex. I do know that the single largest RES (7"+) in the tank is female. I looked her over good when I moved them into a bigger a tank back in July when she was 5". All of these were 1-1/2" to 2" when I picked them up in May with the exception of one 3" RES which is now the 7" female I mentioned above. I do have a 75 gallon tank in the house that I can overwinter a few RES in.
