Gas Exchange in Salamanders

Abstract

Pulmonary and cutaneous gas exchange were measured separately and simultaneously in respirometers of several species at 15[degree] C and at several temperatures in 4 species. Gas exchange data were correlated with tidal volumes and breathing rates. In the lunged salamanders, Ambystoma tiqrinum and Taricha granulosa, pulmonary O2 uptake increased linearly with temperature while cutaneous uptake remained relatively constant at all temperatures. In the lungless plethodontid, Desmognathus quadramaculatus, cutaneous O2 uptake increased linearly with temperature and the buccal cavity accounted for 15% of the total O2 consumption at all temperatures. Increases in pulmonary O2 consumption were directly correlated with increases in tidal volumes and breathing rates. At 15[degree]C the skin accounted for approximately 50% of the O2 uptake in the lunged salamanders, A. tiqrinum, Taricha granulosa, and Salamandra salamandra. In the semi-aquatic plethodontids, D. quadramaculatus, D. monticola, Gyrinophilus porphyriticus, and Pseudotriton ruber, approximately 85% of the oxygen uptake was through the skin. In the terrestrial plethodontid, P. glutinosus, the buccopharyngeal cavity accounted for 24% of the total oxygen uptake. These data indicate that the origin and dispersal of the terrestrial plethodontids may have been linked with the acquisition of a more efficient buccopharyngeal gas exchange.