Microgeographic Varation In Life-history Traits Among Insular Populations Of Takydromus Septentrionalis (Reptilia; Lacertidae) In Zhoushan Islands

I used northern grass lizards {Takydromus septentrionalis), collected from nine geographically separated populations in Zhoushan Islands and Ningbo as model animals to study microgeographic variation in life-history traits and the effects of incubation temperature on hatchling phenotypes.Adult lizards of both sexes did not differ in snout-vent length, thus confirming that T. septentrionalis is a monomorphic lizard. Between sex-differences in head size (head length and head width) and abdomen length were very evident, with males being larger in head size and females being larger in abdomen length. Abdomen length and head size differed significantly among populations.In all involved populations clutch size, clutch mass and relative clutch mass were greater in the first clutch than in the subsequent clutches. Inter-clutch variation in reproductive traits was very evident in the lizard; however, inter-clutch or seasonal shifts in egg size (length and width) and egg mass were not detected in the present study. Geographic variation in egg size, clutch size and clutch mass was evident even when removing the influence of variation in female size, thus signifying that differences in the involved traits are at least partly determined genetically.In all populations egg size was negatively correlated with relative fecundity (residuals derived from the regression of clutch size on females SVL), thus signifying that females with a relatively high level of fecundity lay relatively small eggs. The egg size-number trade-off line differed significantly among populations.Incubation temperature significantly affected incubation length, but not hatching success. Incubation length differed significantly among populations. For example, the mean incubation length at 24-32-28℃was longest in the Shengshan population and shortest in the Liuheng population. Hatching success did not differ among populations.Hatchlings derived from eggs incubated at the same temperature differed among populations in size and morphology. Incubation temperature exerted significant effects on hatchling phenotypes. The locomotor performance of hatchlings did not differ among populations. Incubation temperature affected the number of stops and sprint speed of hatchling but not, the maximal distance traveled in the racetrack.