Meeting Abstract
Ectothermic animals rely primarily on external heat sources and behavioral adjustments for body temperature (Tb) regulation. As the availability of adequate thermal niches varies spatially and temporally, these organisms are subjected to considerable fluctuations in Tb. In its turn, fluctuations in Tb exert profound influence on physiological and behavioral performances. For example, resting metabolic rate (RMR) and evaporative water loss (EWL) are typically related to Tb. Also, RMR and EWL are known to vary interespecifically and with habitat characteristics. Herein, we addressed the ecophysiological potential implications of the variation in metabolism and water balance in a group of Neotropical Crotalinae snakes. To this aim, we measured oxygen consumption rates (as a proxy for RMR) and EWL rates at different temperatures (15, 25, and 35°C) for the following snake species: Bothrops alternatus, B. jararaca, B. moojeni, and Crotalus durissus. These snakes are phylogenetic related and occupy geographical areas that overlap extensively, however, they differ in microhabitat use and other life history attributes. In general, B. jararaca and B. moojeni occupy forested areas, whereas B. alternatus and C. durissus are open area dwellers. We found that RMR and EWL increased with temperature in all snake species. Bothrops jararaca and B. moojeni had higher RMR than B. alternatus and C. durissus at 15 and 35ºC. EWL of C. durissus was the lowest among all the species tested, regardless temperature. At 35°C, B. alternatus had lower EWL than other Bothrops. Broadly, differences in RMR and EWL seem to be consistent with differences in microhabitat occupancy. Financial support: São Paulo Research Foundation (FAPESP)
