Aerobic scope is a measure that relates the minimum energetic requirements and maximum aerobic capacity of organisms. There is widespread discussion in the literature as to how aerobic scope should be measured and in the potential patterns of aerobic scope across taxa. We compare the net aerobic scope (difference between maximum metabolic rate and resting metabolic rate) and factorial aerobic scope (ratio of maximum metabolic rate to resting metabolic rate) across a diverse assemblage of tropical amphibians in the Andes in southeastern Peru.
Results/Conclusions
We show that net aerobic scope is almost entirely determined by maximum metabolic rate in amphibians and is thus best interpreted as a measure of aerobic capacity for the group. We further show that there is extensive variation in factorial aerobic scope in contrast to the predictions of the aerobic capacity model. Comparisons among groups shows that species in the family Craugastoridae have relatively low net and factorial aerobic scope. Low aerobic scope in Craugastoridae may be related to the life history via two potential mechanisms: one, low aerobic scope may be a coadaptation of direct development, or two, low aerobic scope may result from accelerated development times associated with direct development. Further research could distinguish between these potential factors which could be important for understanding evolution of life histories and the prediction of potential physiological effects of climate change.