Effect of temperature on the metabolic rate and evaporative water loss of the scorpion Urodacus armatus

1. There is a highly significant effect of body mass and ambient temperature on metabolic rate and evaporative water loss for the scorpion Urodacus armatus.2. The combined effects of body mass and ambient temperature on metabolic rate are summarized by the multiple regression equation; V(O2) (mul h-1) = 5.07 mass0.911 10(0.037 Ta). The combined effects of body mass and ambient temperature on evaporative water loss (EWL) are summarized by the multiple regression equation; EWL (mg h-1) = 0.204 mass0.634 10(0.026) Ta.3. The pooled allometric mass exponent for metabolic rate of 0.92 is significantly different from 1.0, 0.75 and 0.67. The pooled allometric mass exponent for evaporative water loss of 0.63 is significantly different from 0.75 and 1.0, but not from 0.67, and hence is similar to the allometric relationship for surface area of scorpions.4. The calculated cutaneous component of evaporative water loss was 66.7% at 20-degrees-C, 72.9% at 25-degrees-C, and 74.0% of total EWL at 30-degrees-C.