Water Loss Rates and Desiccation Tolerances for Spiders and Crickets

Despite the importance of water to living organisms, access varies across the globe with high variability over space and time. Seventy-five percent of the world’s freshwater alone is ice while 99% of unfrozen freshwater is underground (Winter et al. 1998). Understanding how terrestrial species respond to water availability and compensate for water stress can provide insight to their behavior, ecology and physiology. The goal of this research was to examine the differences in the evaporative water loss rates and desiccation tolerances of Hogna carolinensis and Acheta domesticus. First, an experiment was conducted to quantify the rate of evaporative water loss of the species Hogna carolinensis and Acheta domesticus. This was done by desiccating twenty specimens of Hogna carolinensis and forty specimens of Acheta domesticus within an environmental chamber set at 30%RH and 30C and measuring their masses until death. Another experiment was conducted to explore how prey hydration influenced predation of Hogna carolinensis. Thirty-nine female specimens of Hogna carolinensis were housed within the environmental chamber under the same conditions, treated to a four day period of starvation and desiccation then fed eight specimens of Acheta domesticus from one of three hydration treatments. Initial observations concluded that there was little difference between how much mass was consumed by the predators across the three treatments