Effect of body size and temperature on skin resistance to water loss in a desert snake

Abstract

1. 1. Respiratory ( E r) and cutaneous evaporation ( E c) O 2 consumption, cloacal and skin temperatures, were measured in the snake Spalerosophis diadema (12–708 g body mass) at three air temperatures (25, 30, 35°C). 2. 2. Area-specific E c increased with temperature (0.365 mg cm −2 h −1 at 35°C vs 0.220 at 25°C); it accounted for 72% of the total evaporation and was independent of body size. 3. 3. The skin resistance to water loss was independent of the snake's size; its reduction at 35°C (164.2 vs 196.0 s cm −1 at 25°C) contributed significantly to the increase in E c. The boundary layer resistance increased with body size. Its magnitude, however, was less than 4% of the skin resistance.