Thermal Ecology Of The Qinghai Toad-headed Lizard, Phrynocephalus Vlangalii (Agamidae)

In this paper, I used Phrynocephalus vlangalii, a viviparous lizard endemic to China, as a model animal to study the adaption to cool climate and traits of thermal ecology. The main results and conclusions are summarized as the following:Sexual dimorphism in morphological traits and coloration pattern was evident in adults but not in sexually immature individuals of P. vlangalii. Adult males were larger in head size, tail length and fore-, and hind-limb length, whereas females were larger in snout-vent length (SVL) and abdomen length. The whole tail tip was black-brown in adult males and the ventral part of the tail tip is slight saffron yellow in adult females.The smallest reproductive female in our sample is 48.1 mm SVL, and all sexually mature females could produce a single litter per breeding season, with a litter size of 2-6 young. Litter size and litter mass were both positively correlated with maternal SVL, and neonate mass was not. The trade-off between size and number of offspring was not detected in the present study. Gestation temperature affected female reproductive success and most examined neonate phenotypes including locomotar performance and early growth. Females that had the opportunity to maintain relatively high gestation temperatures reproduced more successfully than did those at relatively low gestation temperatures (24 ℃ and 28 ℃). The temperature of 28 ℃ is close to the nether thermal threshold for successful embryonic development in P. vlangalii. Pregnant females that suffered longly at the temperatures lower than this level must have dramatically increased adverse effects on embryonic development. A principal component analysis resolved two components (Eigenvalue ≥ 1) from the four size-adjusted female reproductive variables, accounting for 81.7% of variation in the original data. The first component (49.0% of variance explained) had high positive loading for SVL-free values of liter size and litter mass, and the second component (32.7% of variance explained) had high positive loading for offspring size and...