Blood Gases Of The Water Snake, Natrix Tesselluta, And The Desert Snake, Eryx Colubrinus

Abstract

1. This comparative study examines 0^ dissociation curves of blood of two colobrine snakes: an aquatic snake, Natrix tesselluta, and a desert snake, Eryx colubrinus. 2. In the case of the whole blood of the aquatic snake, oxygen capacity was higher and P5o was much lower than in that of the desert snake. 3. Measured P5o value of the aquatic snake was nearly the same as that estimated from the equation postulated by Pough (1977), while P^a value of the desert snake was somewhat higher and the constants of the equation had to be changed into Psn(mmHg) = 30.54+11.92 log W gin). 4. The 0; dissociation curves of both snakes shifted to the left by low temperature and to the right by high temperature. At low temperature, the rates of shifting (AP5o/A°C) were nearly the same in both snakes, while at high temperature, the shifting was much greater in the case of the desert snake. 5. Regarding the Bohr effect, A P5o / A pH was nearly the same at low pH, while at high pH, the rate of shifting of 0; dissociation curve of the aquatic^ snake was much higher than that of the desert snake.