My parents ponds.

[Miguel]

Those are not ponds. Those are lakes.

I am sure you can try allmost all ca cichlids in there. Some will male it through winter, some won't. Those who do will get used, imho.

If it was me, it would be gars and gars......

 

[duanes]

If the ponds have streams, then it is the same as the flooding problem, and the chance of an invasive release is probable.
If you look at the big picture, just one release of a RTC could be the straw that gets that fish outlawed in your state.
Is it worth it?
And there are many sub-tropical cichlids that can easily take below 50'F. Is it worth having those cichlids outlawed?
I keep cichlids that will withstand low 40's, but because my pond freezes solid every winter, and has no outlet, there is no chance of accidental long term survival.
In order to keep my cichlids alive in the winter I must drain my pond, and bring them in.
Unless you are willing to do that, only natives, or already established species should be added.

 

[Duncan6618]

Gars, crappie, bass, trout, stripers, channel cat, blue cats, flathead cats, pikes, walleye...

More than enough cool natives to choose from. I'd much rather stock a small lake with those rather than some little cichlids you're never going to see.