Temperature selection and thermoregulation in the Moorish gecko, Tarentola mauritanica.

Temperature selection in a thermal gradient and the physiological responses to heat exposure were studied in the Moorish gecko, Tarentola mauritanica, from Crete. In association with previous indications that the Moorish gecko has a bimodal activity pattern, we found a bimodal temperature selection with modes at 27-28 and 30-32 degree C. In this respect, it resembles the closely related Israeli gecko, Ptyodactylus guttatus. However, Tarentola is more susceptible to heat exposure and has a moderate thermoregulatory capacity compared to P. guttatus and this is probably related to its reaching more northern latitudes than Ptyodactylus. During heat exposure (up to 40 degree C) oxygen consumption increased significantly and was not sustained by the moderate increase (Q-10 = 1.44) in heart frequency. We found a significantly lower heating rate than cooling rate in Tarentola. This is in accord with allometric predictions for its low body mass and might stem from the high mass-specific evaporative water loss and from the relatively small increment in heart rate during heat exposure which may adaptively retard heat gain from the environment and maximize its activity periods.