摘要
Temperature-dependent sex determination (TSD) is well studied in many species of reptiles, but little is known on how geographic distribution and altitude affect the sex ratio. In the present study, we focused on a population of a viviparous lizard with TSD (Eremias multiocellata) that lives at high altitudes (鈮?900 m) in Tianzhu, Gansu province, China. Gestation temperature had a notable effect on the offspring sex ratio, gestation period, and the mother's body mass. The mothers produced female biased offspring at 25 掳C but male biased offspring at 35 掳C. All female lizards lost weight during pregnancy, and the least loss of the body mass was observed at 31 掳C. The gestation period increased in a non-linear fashion as ambient temperature was reduced. Average litter size was elevated with an increase of gestation temperatures, reached a maximum at 31 掳C, and then declined at 35 掳C. Compared with a previous study on a Minqin population which lives at a lower altitude (鈮?400 m) and warmer climate, the present study obtained a less skewed sex ratio of offspring in the Tianzhu population. Geographic variations also affected offspring morphology between the two populations; females collected from Tianzhu produced larger litters but with a smaller body weight of offspring. These differences may be caused by the adaptive response to the cool climatic and high-altitude environmental conditions.