Oxygen consumption and activity in salamanders: Effect of body size and lunglessness

Oxygen consumption during and after two minutes of strenuous activity was measured at 25°C in three groups of salamanders: temperate zone lunged, temperate zone lungless, and neotropical lungless. No increase in oxygen consumption was detected during two minutes of activity. There were significant differences among the three groups of salamanders in the effect of body size on maximum oxygen consumption and aerobic scope. Small lungless salamanders consumed more oxygen than small lunged salamanders; however, large lunged salamanders consumed more oxygen than large lungless salamanders. Neotropical lungless salamanders showed lower maximum oxygen consumption than temperate zone lungless salamanders, but the effect of body size was similar in these two groups. Small salamanders, both lunged and lungless, pay off oxygen debt at the same relative rate as indicated by percent of scope. Large lungless salamanders pay off debt at a slower rate than large lunged salamanders. Maximum oxygen consumption, aerobic scope, and payoff of oxygen debt are correlated with total respiratory surface area, especially at large sizes. Large lungless salamanders show a reduced capacity to transport oxygen following activity.