Meeting Abstract
Understanding the role that thermal variability has in affecting immunity is key to understanding the causes and consequences of disease in ectothermic vertebrates. As turtles are exceptionally vulnerable to negative effects of global change, understanding the role of thermal environmental change is of specific importance to the group. Recent experimental studies have demonstrated that seasonal variability can directly account for changes in turtle immunity that may render populations more susceptible to disease. Further, studies have demonstrated that rapid temperature change may exacerbate the effects of seasonal change on turtle immunity. Herein, we performed several thermal and immune manipulations in common musk turtles (Sternotherus odoratus) to identify effects of both acute and chronic stimulation of the immune response, and how temperature affects this response. In acute temperature change experiments, we found that rapidly cooled turtles increased phagocytosis rate (P = 0.039) and bactericidal ability (P = 0.023) as compensatory acclimation for the reduced temperature. Similar compensatory acclimation was seen in turtles that were warmed, in which immune rates of production were slowed. In chronic experiments of immune stimulation (via lipopolysaccharide, LPS) and across two temperatures (25 and 30C), patterns were much less clear after 6 weeks of LPS administration, although warmer turtles generally followed the compensatory acclimation, similar to acutely stimulated turtles. Results from this study help shed light on the role of temperature in affecting immunity in ectotherms and the diversity of responses present within ectothermic groups.
