In "The Wildlife Series: Trout" it says golden trout (O. Aguabonita) live normally in temps in the 70s naturally without problems. "Although golden trout are normally associated with cold clear streams and lakes - and indeed that is where most goldens are found - they evolved under very different circumstances. Late summer temps in their native streams in the little kern river drainage often reach well into the 70s Fahrenheit. They are found in cold water habitats only because they were planted there.
Edited by Gavinswildlife, 18 January 2014 - 01:04 AM.