Oxygen-binding properties of Cephalopod blood with special reference to environmental temperatures and ecological destribution.

The oxygen-binding properties of the blood of the cephalopods Todarodes sagittatus, Loligo vulgaris, Architeuthis monachus, and Octopus vulgaris were studied in relation to temperature and pH. The data obtained at pH 7.4 were compared with previously reported data on nine species of cephalopod over the actual range of temperatures at which the animals live in an attempt to define the role of temperature as an effector in the process, and to demonstrate the extent to which temperature influences the ecological range of the various species. For most cephalopods we found Bohr and Haldane factors of lower than −1.0, a result that implies that the Bohr shift does not facilitate the unloading of O2, but may improve the loading of O2 with increased ventilation. The functional significance of the Bohr and Haldane effects appears, thus, to involve stabilization of pH by the isohydric transport of CO2.