The ventilatory and acid-base physiology of the toad, Bufo marinus, during exposure to environmental hyperoxia.

Bufo marinus which were exposed to a step increase of 330-350 torr O2 for a 20 h period ceased lung ventilations and buccal movements were markedly decreased. Toads which were sitting in water did not show elevations in PaCO2 or a depressed pHe but animals which were dehydrated for a 24 h period prior to high O2 exposure developed a mild acidosis, which, typical of most amphibian species, was uncompensated.