Effects of different levels of hypoxia and hypercarbia on ventilation and gas exchange in Boa constrictor amaralis and Crotalus durissus (Squamata: Serpentes).

Ventilation and gas exchange have been studied in relatively few species of snakes, especially regarding their response to environmental hypoxia or hypercarbia. We exposed Crotalus durissus (N = 6) and Boa constrictor (N = 6) to decreasing levels of oxygen (12, 9, 6, 3 % O) and increasing levels of carbon dioxide (1.5, 3.