| Temperature is one of the most important factors determining the population dynamics of rotifers. In the present study, the life history characteristics of four genetically different B. calyciflorus clones (Clone A, B, C and D) collected from Lake Jinghu in summer were studied at 15℃, 20℃, 25℃and 30℃. The main contents and results were presented as the following:1. By means of life table demographic approach, four genetically different B. calyciflorus clones were cultured at 15℃, 20℃, 25℃and 30℃with 3.0×106 cells/mL of Scenedesmus obliquus to investigate their differences in life history characteristics and their responses to increasing temperature. The results showed that the effects of temperature on the survivorship and the fecundity of B. calyciflorus differed with rotifer clones. At the same temperature, and among the four rotifer clones, there were significant differences in the life table parameters including generation time, average lifespan, life expectancy at birth, net reproductive rate and intrinsic rate of population increase except the generation time and the net reproductive rate at 20℃and 25℃as well as the average lifespan and the life expectancy at birth at 20℃, 25℃and 30℃. At 20℃, 25℃and 30℃, the percentage of mictic females in the offspring of the four rotifer clones was significantly different, and that of Clone C was the highest. At 15℃, the individual fitness of Clone B was the highest; at 25℃, the individual fitness of Clone A and B was higher among the four rotifer clones. There were some differences in responses of life history characteristics to increasing temperature among the four rotifer clones. Regardless of the temperature effect, and among the four rotifer clones, average lifespan, generation time, life expectancy at birth, net reproductive rate, intrinsic rate of population increase and individual fitness of Clone D were all the shortest and lowest, and the percentage of mictic females in the offspring of Clone C was the highest.2. The neonate starvation times of four B. calyciflorus clones were studied at 15℃, 20℃, 25℃and 30℃, and the relationships between the neonate starvation time and temperature, body and egg volumes were analyzed. The... |
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