Metabolism and activity of the spanish fringe-toed lizard (Lacertidae: acanthodactylus erythrurus)

Abstract

1.In the field, adult fringe-toed lizards (Acanthodactylus erythrusus) had a mean body temperature of 38.8 ± 0.2 (S.E.) °C while subadults maintained a significantly lowr temperature (x average = 35.4 +/- 0.5 degrees C). 2.Laboratory measurements of oxygen consumption, ventilation frequency, and heart rate indicate that temperatures above 38°C are stressful to subadults. 3.Activity periods of subadults are curtailed by high temperatures for 3 months in summer while the activity of the more thermophilic adults is curtailed only during July and August. 4.Some lizards maintained a high metabolic rate by achieving a low Q10 (x average = 1.3) between 13 and 25°C. 5.Because these lizards initiate activity at black body temperatures of 13°C in their natural habitat, the ability to sustain high rates of aerobic metabolism at low temperatures is probably valuable.