Let them grow about another inch and it will be a lot easier.
Hard enough to tell at that size seeing them live. Doubly hard looking at pics.
Last two pics are likely RES.
Good news is, I'm pretty sure none are pure GSF.
Your HBG SHOULD be mostly males. A male GSF and a female RES is an unusual cross naturally. Can happen artifically but not normal naturally. RES male and GSF female will easily cross if the female GSF has limited partner choices. But is a HBG male more like a BG male or GSF male when it comes to potential crossing with RES? In other words, is a HBG male and RES female also unlikely naturally???
Inquiring minds would like to know.
A magnifying glass I believe would help to see the tiny red tab on 2" fish. Problem is, you would know if they had RES genetics but still not know if they were pure.
I bet they will be a pretty good sunfish to catch even if you do get a few HBG/RES hybrids.
