Don, thanks for the reply on water temp observations..
I would wonder if by chance your local variety/strain of YP are more tempered to that area? Only reason I say that is in my research of YP in the nearest strain to that region closest to me, I find several data points suggesting YP growth tends to slow to a minimum at a surprising 50-52 degrees and also slows when reaching 80 degrees. But I've also found data that suggests SE variations can tolerate near 92 degree water with continued growth at a high rate above 85.
It would seem this perch can assume many faces depending on it's origin, especially in data points finding the YP as very tolerable of low D.O. compared to other species, yet "doesn't" tolerate higher temps in the central U.S., which leaves me wondering if some strains were transported too far out of their normal range, leaving an impression that this fish does not do well under "X" conditions.?
It seems to be tuff to get answers to something like that, such as I'm having trouble finding now with the closest source to me.
If nothing else, my data will only be as good as what I can prove.