Ewest,
Good info. What I find even more intriguing is some species have evolved to handle different temps even though they are still the same species. That's why from my observation you're better off stocking your pond with fish that are adapted to your region. An example would be I would not, given the choice, plant my pond with bluegills from one of the big Arkansas fish farms vs. local bluegill. I just don't think they would be as adaptable to our winters.
I have also had bad luck ( poor survival) with fish from an RAS (Recirculating Aquaculture System) planted into an outdoor pond, but I believe that is not the same thing as the species evolving different tolerances. The RAS fish had no stamina and catching and releasing them killed them. They may also not have had a normal immune system as they may not have been exposed to certain pathogen before being planted into the pond.
Last edited by Cecil Baird1; 02/07/08 11:23 AM.
