Cutaneous Water Loss at Rest and Exercise in Two Species of Marsupials

Abstract

The relative roles of heat storage, evaporative, and non-evaporative heat loss were examined in the brushtail possum, Trichosurus vulpecula, and the Tasmanian devil, Sarcophilus harrisii, during exercise. Rates of water conductance across the skin were also measured at rest and while running at two ambient temperatures. Evaporative heat loss from the general body surface in S. harrisii is a minor contribution to the overall heat balance, and sweat gland function is not apparent. T. vulpecula relies more on heat loss mediated by cutaneous evaporation than from respiratory routes, but changes in cutaneous blood flow are more important than glandular activity in augmenting this response. These results and earlier reports in the literature suggest that the occurrence and function of cutaneous evaporation varies among marsupial species.