Geographical Distribution and Morphological Variability of the Rapid Racerunner,Eremias velox (Pallas,1771)(Reptilia,Lacertidae) in the Eastern Periphery of Its Range

摘要

Phenotypic traits are usually correlated with the environment where organism occurs. In this study, the distribution of Eremias velox in the eastern periphery of its range was specified, and its morphological variation was analyzed. Linear dimensions, pholidosis, coloration and pattern features were compared among 135 specimens from nine populations inhabiting the Balkhash, Ili and Alakol basins, Junggar and Turpan depressions in the territory of Southeast Kazakhstan and Xinjiang, Northwest China. The populations from the Junggar Depression(Kuytun, Shihezi and Urumqi) were characterized by higher mean values of linear characters, the number of scales across the middle of the body and gular, and were similar in the dominant coloration patterns. Small size, dark coloration and almost complete dominance of the striped-type coloration pattern among the specimens from the Alakol Lake islands seem to have an adaptive significance associated with the isolation of the population and type of their habitats. The subspecies Eremias velox roborowskii(endemic to the Turpan Depression) is elevated to species level, as supported by morphological divergence congruent with molecular and geographical data, including its peculiar type of coloration pattern, significantly lower amount of femoral pores and a higher percentage of specimens with one enlarged preanal scale(72.7%). These results together confirm a high degree of variability in morphology for E.veloх in the eastern periphery of its range, reflecting a complex orography and the existence of multiple geographical barriers in this territory.