THE RESPIRATION OF PUFFER FISH

Abstract

1. A method is described for studying environmental factors which affect the respiration of fishes. 2. An increase in temperature of water surrounding puffer fishes is followed by increased oxygen consumption by the fishes, a greater quantity of water pumped through the branchial chamber, and a faster respiratory rhythm. The percentage of dissolved oxygen absorbed remains constant at all temperatures observed. 3. Increase in hydrogen ion concentration inhibits oxygen consumption by marine fishes, but addition of CO2 has a more pronounced effect than addition of HCl at the same pH. 4. The results indicate that marine, fishes apparently remove dissolved oxygen from sea water by an efficient mechanism of gill aëration. Fishes absorbed about 46 per cent of dissolved oxygen from sea water at all observed oxygen tensions.