Respiratory control of arterial pH as temperature changes in rainbow trout Salmo gairdneri.

RANDALL, D. J., AND J. N. CAMERON. Respiratory control of arterial pH as temperature changes in rainbow trout Salmo gairdneri. Am. J. Physiol. 225(4) : 997-1002. 1973.-Arterial blood pH decreased as temperature increased, dpH/dT was 0.017 unit/“C and was independent of the acclimation history of the fish. Ventilation volume increased in proportion to oxygen uptake with temperature. Changes in water flow over the gills with temperature were associated with large changes in breathing rate and small changes in the volume of water pumped each breathing cycle. Percent oxygen extraction from water flowing over the gills and arterial oxygen tension did not change with temperature. The partial pressure of CO2 in arterial blood and the content of molecular CO2 in plasma did not change with temperature. Decreases in blood pH were associated with a fall in plasma total COP and bicarbonate.