Most GSF will have a translucent orangish border on their opercular tab. A few years ago it was hard for me to keep from being confused with a RES because of this.
But the GSF border will be more of a translucent nature where the RES will be either a solid orange or solid red. Also the GSF border will kind of wrap around the tab more whereas the RES tends to be mostly on the end of it.
I am getting a bunch of natural hybrids out of my sediment pond now and some even in my forage pond which is SUPPOSED to only have RES. With very small fish and RES crossed with GSF it gets difficult for me to identify. But generally if I get them side by side, I can see the GSF characteristics in the hybrid and none in the pure RES.
GSF will be thick. Much thicker than a BG. Much more like a LMB. The GSF will not be as tall as a BG, but a lot thicker.
Where these are not your target fish, I would just cull the ones you catch. You are going to have more of them even if you do cull and by not culling you might end up with a lot more than you want. So the safe thing for your goals is to cull, in my opinion.
If you catch smaller ones (sized so your largest LMB can eat them) you can clip their tail fin off with scissors and put them back in for LMB food. With the tail fin clipped they can not swim very fast, swim erratically, and that makes them easy targets for LMB. I have tail clipped hundreds of GSF and have never re-caught one. So they get eaten pretty quick. It is a way of recycling the fish food you have been feeding the GSF. They are definitely chow hounds.
Good luck and have fun!
Last edited by snrub; 09/05/16 12:03 PM.
