Evaporative water loss in anuran amphibia: A comparative study

1. 1. Evaporative water loss, at different rates of air flow, was measured in the anurans, Rana pipiens, Bufo bufo, Xenopus laevis and Agalychnis dacnicolor. It was much less in the latter tree frog, but was similar in the other three species. 2. 2. Inhibition of pulmonary respiration did not significantly change total evaporation nor could the interspecific difference in water loss be related to O₂ consumption. Water loss corresponded to 60-100 mg H₂O/cm³O₂ used. 3. 3. Evaporation from the amphibian integument was less than that from a planar free-water surface. The difference from three of the species may however be due to the animal's shape. Agalychnis, behaved quite differently and water appeared to have a restricted access to the outer surface of the skin in this frog. 4. 4. The observed variation could not be accounted for by differences in the thickness or lipid content of the skin.