For comparison, here are some I trapped out of my forage pond today. I would not swear they are 100% RES because every now and then I get one that looks like it has some GSF in it. Really hard for me to tell for sure with these small fish. As they grow a little it should get more obvious.
This pond (supposedly) has only RES, GSH and FHM in it. So they should be pure RES. But I also trapped a fingerling GSF out of this pond last week. I suspect it swam up the overflow tube from my main pond during a recent high water event, but I will never know for sure.
I do not worry so much about it because I would not mind having RES/GSF hybrids. But this pond was supposed to raise fingerling RES to put in my main pond to increase their numbers there.
