荒漠沙蜥繁殖生态研究

REPRODUCTIVE ECOLOGY OF PHRYNOCEPHALUS PRZEWALSKII

荒漠沙蜥（Ｐｈｒｙｎｏｃｅｐｈａｌｕｓｐｒｚｅｗａｌｓｋｉｉ）１年繁殖１次，有明显的季节性周期。４月初出蛰时雄性精巢已相当发育，５月其重量和体积最大，６月变小，进入精子发生的晚期，７月降到最小，８月开始回升，１０月中旬入蛰时已接近春季出蛰时水平。１年内仅７月精巢中无精子。雌性出蛰后卵细胞开始发育，４月下旬进入成熟期，６月达高峰，７月下降，８月进入休止期。每雌年产卵１～３枚或１～４枚，平均１．８３（ｎ＝４８，１９８７）和２．１７（ｎ＝４８，１９９３）。特定体长组的生殖率是影响种群年平均生殖率的主要因素。生殖周期与光周期相符，光周期是影响荒漠沙蜥生殖周期的主要气候因子。

The reproductive ecology of Phrynocephalus przewalskii was studied in Shapotou of Ningxia. Male and female P. przewalskii were examined monthly in 1987 and 1993. Seasonal changes in the histological morphology of the testes and developments in ovum cells were observed. The reproduction of P.przewalskii occurs from spring to summer every year, showing significant seasonal circle.When adult males concluded hibernation their testes have fairly developed. The weight and the volume of the tests were upto greatest in May. Both weight and volume regullarly decreased in June. From April to June the proportion of lizards with testes histologically in full breeding condition(stage 6) increased month by month. Both weight and volume of testes changed into smallest and there were not sperms in seminiferous tubules in July.The weight and the volume of testes gradully rised in August.In mid-Octobor before lizards began to biber 'ate their testes were close to that in April.There were spermatogenesis in seminiferous tubules from August to Octobor. After females ended hibernation in April their ovum cells started to develop.The development in ovum was up to mature stage in the end of April.The proportion of females with mature ovum reached a peak in June.The proportion of lizards with mature ovums decreased in July.The development of ovums got into rest stage in August.The breeding rate of population was 1～3 or 1～4 eggs/♀·a,averaging 1.83(n=48,1987) and 2.17(n=48,1993).It was affected by breeding rate in specified SVL series. Ecological factor that affects productive circle of lizard population was illumination time.The reproductive circle corresponded with illumination cycle.