温度和食物密度对裂足臂尾轮虫生命表统计学参数的影响

In this paper, effects of temperature (15℃, 20℃, 25℃ and 30℃) and Scenedesmus obliquus density (1.0×106, 3.×106 and 5.0×106 cells/ml) on life history parameters including life expectancy at hatching, generation time, gross reproductive rate, net reproductive rate, intrinsic rate of population increase and proportion of sexual offspring of Brachionus diversicornis were studied by means of individual culture. The results showed that temperature affected significantly life expectancy at hatching, generation time, gross reproductive rate, net reproductive rate and intrinsic rate of population increase, but did not affect proportion of sexual offspring. Food level affected markedly gross reproductive rate and net reproductive rate, but did not affect life expectancy at hatching, generation time, intrinsic rate of population increase and proportion of sexual offspring. Food level and temperature, independently and in interaction, did not significantly influence all the life table demographic parameters. Both the life expectancy at hatching and the generation time decreased with increasing temperature. The net reproductive rate was the lowest at 15℃, the highest at 30℃, and similar at 20℃ and 25℃. The gross reproductive rate was lower at 15℃ than at 20℃, 25℃ and 30℃, and those at the latter three temperatures were similar. Both the net reproductive rate and the gross reproductive rate were higher at 3.0×106 cells/ml than at 1.0×106 cells/ml and 5.0×106 cells/ml of Scenedesmus, and those at the two latter food levels were similar, respectively.