湛江和三亚萼花臂尾轮虫生活史特征的比较概论.doc

湛江和三亚萼花臂尾轮虫生活史特征的比较研究 摘 要：在实验室中以浓度为2.0×106 cells/ml的斜生栅藻 ( Scenedesmus obliquus) 为食物运用生命表统计学等方法比较研究了采自不同气候带不同品系萼花臂尾轮虫（Brachionus calyciflorus）在20℃、24℃和28℃三个温度下的生活史特征。结果表明，采自中热带的萼花臂尾轮虫的生殖期、平均寿命、产卵量、净生殖率几乎都显著小于采集于边缘热带品系，也就是说，中热带轮虫的生长发育速度快于边缘热带轮虫，但采自中热带的轮虫寿命短，所产后代数量少，种群增长能力也不如边缘热带轮虫，说明不同气候带的轮虫采取了不同的生活史对策。位于两个气候带的轮虫的各个发育阶段历时、平均寿命、存活时间、生命期望和世代时间几乎都随着温度的升高而显著缩短说明高温会使轮虫的生长发育速度加快，从而导致其平均寿命等缩短；轮虫的内禀增长率则随着温度的升高而显著增大，并在28℃下达到最高，说明高温有利于中热带和边缘热带轮虫的种群增殖，这可能与轮虫对所处气候带水域环境温度的长期适应有关。 关键词：萼花臂尾轮虫；生活史特征；气候带；温度 Comparative Studies on the Life History Characteristics of Brachionus calyciflorus from Zhanjiang and Sanya WANG Yinzhong, College of Life Sciences Abstract: The life history characteristics of different Brachionus calyciflorus strains collected respectively from different climatic zones were studied at three temperatures (20℃, 24℃ and 28℃) with 2.0 × 106 cells / ml of Scenedesmus obliquus as their food in the laboratory by means of life-table demography. The results showed that the durations of reproductive period, mean lifespan, egg production, net reproductive rate of the B. calyciflorus from the central tropics were almost lower than those of the strain from the northern edge of tropics signi?cantly, which indicated the growth of the central tropical strain was faster than the northern edge of tropical strain, and B. calyciflorus from different climate regimes adopted different life history strategies. The durations of each developmental stage, mean lifespan, survival time, the life expectancy at hatching and generation time of B. calyciflorus under two different climate regimes almost shortened signi?cantly with the increasing temperature, showing that high temperature accelerated the growth rate of rotifer. On the other hand, the intrinsic rate of population growth increased signi?cantly and reached a maximum at 28℃ with the increasing temperature, which indicated high temperature benefited the population growth of the B. calyciflorus under the centr