Physiological flexibility in the Andean lizard Liolaemus bellii: seasonal changes in energy acquisition, storage and expenditure

Naya, DE; Veloso C.; Bozinovic F.

Abstract

According to the "barrel model", an organism may be represented by a container, with input energy constraints (foraging, digestion, and absorption) symbolized by funnels connected in tandem, and energy outputs (maintenance, growth, and reproduction) symbolized by a series of spouts arranged in parallel. Animals can respond to changes in environmental conditions, through adjustments in the size of the funnels, the fluid stored inside the barrel, or the output flow through the spouts. In the present study, we investigate the interplay among these processes through the analysis of seasonal changes in organ size and metabolic rate in a lizard species (Liolaemus bellii) that inhabits extremely seasonal environments in the Andes range. We found that digestive organ size showed the greatest values during spring and summer, that is, during the foraging seasons. Energy reserves were larger during summer and autumn, and then decreased through winter and spring, which was correlated with overwintering maintenance and reproductive costs. Standard metabolic rate was greater during the high-activity seasons (spring and summer), but this increase was only noticeable at higher environmental temperatures. The ability of many lizard species to reduce their maintenance cost during the cold months of the year, beyond what is expected from temperature decrease, is probably related to their success in coping with highly fluctuating environments. Here, we demonstrate that this ability is correlated with high physiological flexibility, which allows animals to adjust energy acquisition, storing and expenditure processes according to current environmental conditions. © 2008 Springer-Verlag.

Más información

Título según WOS: Physiological flexibility in the Andean lizard Liolaemus bellii: seasonal changes in energy acquisition, storage and expenditure
Título según SCOPUS: Physiological flexibility in the Andean lizard Liolaemus bellii: Seasonal changes in energy acquisition, storage and expenditure
Título de la Revista: JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTAL PHYSIOLOGY
Volumen: 178
Número: 8
Editorial: SPRINGER HEIDELBERG
Fecha de publicación: 2008
Página de inicio: 1007
Página final: 1015
Idioma: English
URL: http://link.springer.com/10.1007/s00360-008-0292-6
DOI:

10.1007/s00360-008-0292-6

Notas: ISI, SCOPUS