Studies of water loss in two species of lizards

Abstract

1.1. The total water loss of the lizards Anolis carolinensis and Uta stansburiana hesperis was determined in dry air at 30°C and convection rates of 0, 252 and 500 cm3/min. Anolis lost water more rapidly than Uta at all three convection rates, the respective mean values at 252 cm3/min being 0·282 and 0·156 per cent initial wt. lost/hr.2.2. At 30°C and 252 cm3/min the estimated contribution of respiratory water loss for both Anolis and Uta was equal to 52 per cent of the total water los. Cutaneous evaporation accounted for an estimated 42 per cent of the total water loss of Anolis and 39 per cent of the total for Uta.3.3. The greater surface area per unit weight of Anolis undoubtedly contributes to the higher rate of cutaneous evaporation but is insufficient to account for the estimated difference between the two species.4.4. The adaptive significance of the rate of water loss is suggested by the fact that the more economical species (Uta) is found in a more arid habitat.