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°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°C) oxygen consumption increased significantly and was not sustained by the moderate increase (Q₁₀ = 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.