Temperature influences on California rainbow trout physiological performance

摘要

Although thermal influences of the physiology of rainbow trout (Oncorhynchus mykiss) have been widely studied, there is little information about the responses of different genetic strains to temperatures. The effects of water temperature (10, 14, 19, 22, and 25 deg C) on food consumption rate, growth rate, gross conversion efficiency, resting routine oxygen consumption rate, upper critical thermal tolerance and critical swimming velocity were investigated in juvenile rainbow trout of the Eagle Lake (O. m. aquilarum) subspecies and the Mt. Shasta strain. No strain-related differences in conversion efficiency, oxygen consumption rates, thermal tolerance or swimming performance were observed in 1995 (19, 22, and 25 deg C) or 1996 (10, 14, and 19 deg C), but Mt. Shasta strain trout grew faster at highest temperatures than did Eagle Lake trout. Food consumption rates, growth rates, conversion efficiency, and oxygen consumption rates declined at the extreme temperatures (10 and 25 deg C) in both Eagle Lake and Mt. Shasta trout. Swimming performance was temperature-independent between 10 and 19 deg C (overall mean: 5.43 body lengths s~-1).