In my pond (FH/RES) I'm thinking that Gambusia might be a good management tool under certain circumstances. If FH continually overpopulate I could add Gambusia to control them. There are plenty of FH fry in my pond now, and if I had Gams I'm sure they would be feasting on them. I suppose the Gams would also prey on RES fry as well. Would the RES prey on Gams at all?

I may not have a choice about the Gams because they usually stock themselves around here.

If I reach the point in this test where I need a larger predator to control RES I think I'll try Chain Pickerel first. When they are smaller they would prey on the FH also and then they would have to target the RES as they got larger. CP are native to GA and the world record of 9 lbs 6 oz is from here. They often live is swampy water so I imagine they would be fairly tolerant of warm water/low DO.