Meeting Abstract
Adaptive radiation studies mainly focus on morphological characters and often overlook the physiological consequences to these adaptations. The link between morphological and physiological changes with environmental variation would allow for the understanding of why an adaptation would arise and why a lineage has diversified. The endemic land snails of the genus Naesiotus form the most species rich adaptive radiation of the Galapagos islands with over 80 species described. These snails inhabit most islands from low elevations that are hot and arid to higher elevations that are cool and humid. Along this climatic gradient, Naesiotus species present a diverse spectrum of shell size, shape, and color. We predict that snails in hot and arid climates have lower basal metabolic rates and smaller shell apertures which would minimize water loss. We quantified the metabolic rate (calculated from oxygen consumption and carbon dioxide production) and water loss of 13 species distributed along two Galapagos elevational transects using a Sable Systems International FoxBox. We measured spatial and temporal variation in temperature and humidity along the transects and tested whether species metabolic rate changes due to morphology or environment or both. This research work will help establish how snail physiology differs along elevational gradients and whether snail shell morphology represents an adaptation to these differences.
