The Significance of the Bohr Effect in the Respiration and Asphyxiation of the Squid, Loligo Pealei

Abstract

1. The oxygen and carbon-dioxide content of the arterial and venous blood of the squid, Loligo pealei, have been measured. 2. Using a nomographic method of analysis it is shown that the reciprocal effects of oxygen and carbon dioxide upon the respiratory properties of squid haemocyanin account for one-third of the respiratory exchange. 3. The venous blood is estimated to be 0.13 pH unit more acid than the arterial blood. 4. Death from asphyxiation occurs when the oxygen and carbon-dioxide pressures are such that the arterial blood can combine with only 0.5 to 1.5 volumes per cent, oxygen. Carbon dioxide exerts no toxic effect except through its influence on the oxygenation of the blood. 5. The haemocyanin of the blood is of vital necessity to the squid, because the amount of oxygen which can be physically dissolved in blood is less than the amount which is necessary for the maintenance of life.