Meeting Abstract

P3.82  Monday, Jan. 6 15:30  Measuring Cutaneous and Pulmonary Gas Exchange and Water Loss of Hibernating Bats CAREY, C.S.*; BOYLES, J.G.; Southern Illinois Univ., Carbondale; Southern Illinois Univ., Carbondale charleve@siu.edu

An emerging fungal-borne disease of concern in North America, white-nose syndrome (WNS), is responsible for a catastrophic bat epizootic. The “dehydration hypothesis” postulates the causative fungal agent (Pseudogymnoascus destructans; Pd) of WNS damages the wings in such a way as to disrupt water and electrolyte balance, which is a crucial challenge for bats. To test the dehydration hypothesis and further elucidate the pathogenesis of WNS, we must understand physiological processes that occur during hibernation. To this end, we tested various respirometry chambers (some from previous studies on non-hibernating species and some newly designed chambers) to investigate which design best separates cutaneous and pulmonary gas exchange and water loss of hibernating bats. Designs were tested on big brown bats (Eptesicus fuscus) in spring 2013 with the most promising design selected for further investigation later in the year. The best design had no significant leaks between the head and body chambers or outside air. Also, bats were able to maintain steady-state torpor for three hours. Now, with this chamber, relative contributions and changes of pulmonary and cutaneous gas exchange and water loss due to WNS-associated wing damage can be estimated. Bats will undergo manipulative tests to address our predictions related to the dehydration hypothesis; a) water loss will increase when outer sebaceous oil on the wings are removed, and b) pulmonary gas exchange will increase when cutaneous gas exchange is restricted. Specifically, we are measuring oxygen, carbon dioxide, and water vapor of hibernating bats. Not only does this study allow us to expand our understanding of the physiological complexities of hibernation, but also the WNS epizootic.