THE INFLUENCE OF CARBON DIOXIDE ON THE UTILIZATION OF OXYGEN BY SOME FRESH-WATER FISH

Abstract

The influence of carbon dioxide on the utilization of oxygen by 16 species of fresh-water fish from Algonquin Park, Ontario, Canada, has been measured by sealing fish individually in bottles containing water adequate in oxygen and with various concentrations of carbon dioxide. At death the ambient respired water was analyzed for free carbon dioxide and oxygen. Results give specific curves, which show that the oxygen in the respired water at the time of death was higher when the tension of carbon dioxide was increased. When the tension of carbon dioxide was low, the oxygen left in the water ranged from a tension of 4 mm. Hg for the northern brown bullhead, Ameiurus nebulosus, to 19 mm. Hg for the common brook trout, Salvelinus fontinalis. Carbon dioxide tensions causing death when a tension of 160 mm. Hg of oxygen remained in the respired water ranged from 80 mm. Hg for the northern blacknose shiner, Notropis heterolepis heterolepis, to 338 mm. Hg for the northern brown bullhead.