Macrophysiology of subterranean mammals. Ctenomys: a model to assess the effect of global warming on physiology and distribution.

ANTENUCCI CD; LUNA F

Alessandria

Congreso; XXVII Congress of the European Society of Comparative Biochemistry and Physiology; 2010

Macrophysiology aims to explain how physiological traits are affected by environmental variability over large geographic distances. The knowledge of physiological strategies to cope with long-term environmental and geographical changes is a key for conservation biology. Thermal physiology influences ecological and evolutionary animals´ success, and represents a valuable tool to understand the effect of these changes on animal distribution.We are unable to know the effect of global warming on species survival but, we can use species that underwent similar selection pressures as a proxy. Subterranean rodents are an excellent model to evaluate the effect of extreme conditions on physiology and distribution. Its evolution was linked to an aridization period (late Cenozoic), following by a peak in genus diversification during a warm period (Pliocene). Ctenomys is exposed to extreme ambient temperatures (Ta) when forage, undergo overheating during digging and is widely distributed. We assess the effect of Ta on energetics and thermogenesis at molecular and organismic levels. We also explored which are the factors affecting metabolic scope and thermal balance. Finally, we investigated if large scale environmental patterns modulate thermal biology. Ta was not a good predictor of basal and maximum metabolic rate. Molecular and physiological patterns of thermoregulatory heat production were species-specific. In smaller species, non shivering thermogenesis was the main mechanism, whereas shivering was in bigger species. Biogeographical factors that influence surface-dwelling species have no effect on Ctenomys. We illustrate how macrophysiology could provide insights into energetics within Ctenomys, and their consequence on species distribution in a changing world.