Table 1. Thermal tolerances for trout species found in Georgia. Stocking of rainbow and brown trout has resulted in the establishment of reproducing populations. Species Origin Upper thermal limit (a) Source Oncorhyncus mykiss (Rainbow trout) Introduced ~21°C Scott and Crossman (1973) Salmo trutta (Brown trout) Introduced ~24°C Scott and Crossman (1973) Salvelinus fontinalis (Brook trout) Native ~20°C Power (1980) (a) Thermal limits for different life stages (spawning, rearing, migration, etc.) and physiologic characteristics (swimming speed, gamete production, disease resistance, etc.) of each species may vary from the values listed above (e.g., Richter and Kolmes 2005).