Meeting Abstract
P2-156 Sunday, Jan. 5 Does reproductive investment trade off with hardening or cross-tolerance related to heat and desiccation? HARTER, LN*; STAHLSCHMIDT, ZR; U Pacific; U Pacific l_harter@u.pacific.edu http://stahlschmidtlab.weebly.com/
Animals exhibit physiological adjustments to many different environmental stressors, including heat waves and droughts (water limitation). For example, prior exposure to a given stressor (e.g., heat) can improve an animal’s performance in a subsequent exposure to the same stressor, which is known as heat hardening or acclimation. Animals may also exhibit cross-tolerance where prior exposure to one stressor (e.g., heat) improves an animal’s performance in response to a different stressor (e.g., desiccation). Although important for survival, hardening and/or cross-tolerance may tradeoff with other important processes, such as reproductive investment. Therefore, we tested for heat and desiccation hardening and cross-tolerance in short-winged female variable field crickets, Gryllus lineaticeps. Newly emerged adults were isolated, and they were weighed 5 d later because body mass at this age strongly correlates with reproductive investment (dry ovary mass). Then, each animal had its food removed and was subjected to pre-treatments for heat (42°C for 100 min.), desiccation (silica-dried air for 24 h), or control (normal rearing temperature [28°C] and access to water). After recovery from their pre-treatments, animals’ performance for heat tolerance (critical thermal maximum) or desiccation resistance (duration of life without wa-ter) were assessed and body size (femur length) was determined. Thus, we tested for heat and desiccation hardening or cross-tolerance, and tested whether investment into reproduction traded off with hardening or cross-tolerance. The co-occurrence of heat waves and drought are expected to increase with climate change, and our results will provide insight into fitness-related costs as-sociated with physiological adaptations to these two stressors.