OXYGEN CONSUMPTION IN AN ANTARCTIC HEMOGLOBIN-FREE FISH PAGETOPSIS MACROPTERUS AND IN 3 SPECIES OF NOTOTHENIA

1. The rate of oxygen consumption was determined in an Antarctic hemoglobin-free fish, Pagetopsis macropterus, and in three species of Notothenia, all of which have hemoglobin. In P. macropterus, the consumption at 0°C ranged from 0·012 to 0·022 ml O2/g per hr, one-half to one-quarter of that in other fishes. In all cases, the rate was little affected by the oxygen tension in the water when it was lowered from approximately 160 to 20 mm Hg for Notothenia, or to 30 mm Hg for P. macropterus. In spite of the lack of hemoglobin, P. macropterus appears to have an efficient and well-regulated system for oxygen uptake. © 1969.