中文摘要：

对采自中国云南省高海拔地区一稀有低额溞-喜马拉雅低额溞（Simocephalus himalayensis）在低海拔地区实验室内不同温度梯度下的生长及生殖能力进行了研究。结果表明：高海拔地区生活的低额溞在低海拔地区的相应环境中同样生长繁殖良好,其繁殖率、最大生殖量及种群的增长能力不受海拔高度及不同环境条件的影响。在一定温度条件下（15—31℃,误差为±1℃）,喜马拉雅低额溞的发育速率随温度的升高而加快,但在32℃时减慢。在通常培养条件下,喜马拉雅低额溞一般有4个幼龄期（15℃时部分溞体有5个幼龄）,16—19个成龄,平均寿命通常为74d（15℃）、54d（20℃）、39d（25℃）和24d（30℃）。平均总产仔量在15—25℃最高,分别为449个（15℃）、482个（20℃）和447个（25℃）。各温度梯度下的体长增长模型都表明,其体长与龄期之间存在显著的对数关系。每溞平均生殖量以20℃时最高,种群的内禀增长率（rm）和一生的生殖次数都以25℃时最高,净增殖率（R0）以20℃最高。喜马拉雅低额溞最适合的繁殖温度范围在15—25℃。研究还对该种与相应种类在不同温度条件下的生殖量和生物学特性进行了比较。

英文摘要：

A rare species in Simocephlus-Simocephalus himalayensis,which was collected on altiplano area in Yunnan Province,China,were studied.The samples were collected both in the water area at jokul Meili（altitude,2288 meter,N 28°28＇164″;E 98°47＇218″） and Shangri-la（altitude,3318 meter,N 27°52＇76″;E 99°39＇386″） in Yunnan Province,China.The samples was reared at 15℃,20℃,25℃,30℃ and 32℃（±1℃） respectively,and fed with Scenedesmus obliquus at density of 3×10^5 cell/mL.The experiment was carried out under a constant light regime of 12h.Observed four times each day,the body length was measured,the instars duration and the brood size were recorded.The result showed that the Simocephalus himalayensis which lived on the water areas of high elevation were well lived on the water areas of low elevation.Its reproduction,population parameters regarding growth,longevity and population increase were not affected by the living environment of high elevation.The main result of Simocephalus himalayensis showed below：1.Simocephalus himalayensis generally had 4 preadult instars,16—19 adult instars at 15℃,20℃and 25℃ respectively,8 adult instars at 30℃ and 32℃.The mean longevity of individuals was estimated to be 74 days at 15℃,53.5 days at 20℃,38.5 days at 25℃,24 days at 30℃ and 17.5 days at 32℃.2.The growth of body-length（L,in mm） in relation to instars（t,in instar number） could be described as：L = 1.0817Ln（t） ＋ 0.1649（15℃） L = 1.0143Ln（t） ＋ 0.3694（20℃） L = 0.8596Ln（t） ＋ 0.4342（25℃） L = 0.5929Ln（t） ＋ 0.6899（30℃） L = 0.6506Ln（t） ＋ 0.4902（32℃） 3.Temperature was a most important factor influencing the growth.In certain range of temperature,the growth speed directly proportional to the temperature,higher temperature could shorten the time for the development to maturity and life span.The relationship between the instar at maturity and water temperature of 15—32℃,for female was：y = 30250x-1.7418;The rel