The survival of carp (Cyprinus carpio) outside water.

The possible use of the swimbladder of carp as auxiliary respiratory organ when the animals are exposed to air has been studied. After exposure to air, blood pH and pO2 and mean swimbladder O2 concentration decrease and blood pCO2 increases in normal animals. Exposure to air after ligation of the pneumatic ducts results in increases in blood pH and pCO2 and decreases in blood pO2 and swimbladder carbon dioxide concentration. Possible reasons for these observations are discussed.