Muscle Protein Synthesis Rates during Temperature Acclimation in a Eurythermal (cyprinus Carpio) and a Stenothermal (salmo Gairdneri) Species of Teleost

Rates of protein synthesis were measured in the white myotomal muscle of carp (Cyprinus carpio) and rainbow trout (Salmo gairdneri) at a number of environmental temperatures before and after they had spent an acclimatory period at these temperatures. For carp previously kept at a mid-range temperature of 15 °C the rates of muscle protein synthesis showed a Qio of 3-07 over the range of 10—25 °C. Acclimation to low temperatures resulted in the rate of protein synthesis being elevated whilst acclimation to high temperatures resulted in the depression of protein synthesis rate. Rainbow trout also initially maintained at 15 °C showed an initial Qio of 3-57 between 5 and 20 °C. In this species, however, there was no significant difference in protein synthesis rates after being kept for 1 month at any given temperature within this temperature range. In the carp where acclimatory changes were recorded, it was found that these changes occurred at a faster rate at 25 °C than at 10°C. The ability of the carp to modify its protein metabolism in this way is discussed as a strategy for reducing temperature effects upon growth and muscle function.