examining possible physiological mechanisms underlying these population differences in thermal tolerance, juvenile sockeye salmon from the Chilko River and Weaver Creek did not show any differences in force-frequency response of the heart or cardiac pumping capacity when reared in common garden temperatures at 5 °C and 14 °C. Therefore, the physiology underlying these differences in thermal tolerance has yet to be determined. Gallery References External links NOAA Fisheries sockeye salmon web page FishBase entry for Oncorhynchus nerka Animal Diversity Web entry for Oncorhynchus nerka Species Profile National Geographic Sockeye salmon Watershed Watch Salmon Society A British Columbia advocacy group for wild salmon Salmon/Steelhead page of the USDA Forest Service, Pacific-Northwest Fisheries Program. Salmon Oncorhynchus Fish of the Pacific Ocean Fish of North America Fish of East Asia Fish of Japan Fish of the Western United States Cold water fish Fish described in 1792 Taxa named by Johann Julius Walbaum