温度和铜绿微囊藻毒性对萼花臂尾轮虫生活史参数的影响

文章开展了25℃下两个品系铜绿微囊藻(有毒与无毒)不同浓度对萼花臂尾轮虫生活史的影响研究, 及在5个温度下不同浓度有毒铜绿微囊藻对萼花臂尾轮虫生活史影响的研究。结果表明铜绿微囊藻毒性、浓度及二者交互作用对轮虫生活史参数净生殖率(R₀; F=31.83, P<0.01; F=30.36, P<0.01; F=13.51, P<0.01)、内禀增长率(r_m; F=34.67, P<0.01; F=18.73, P<0.01; F=12.99, P<0.01)均有显著影响; 温度、铜绿微囊藻浓度及二者交互作用对轮虫生活史参数净生殖率、内禀增长率也均有显著影响。无毒铜绿微藻在低浓度(1×104 cells/mL)下对轮虫种群有促进作用, 可作为轮虫食物来源, 但缺乏脂肪酸等营养物质, 食物质量比蛋白核小球藻低; 在高浓度(1×105和5×105 cells/mL)下轮虫摄食无毒铜绿微囊藻机率变大, 整体食物品质下降, 对轮虫有抑制作用。有毒铜绿微囊藻对轮虫种群的抑制作用更加明显, 微囊藻浓度升高, 净生殖率和内禀增长率显著下降。研究结果还表明30℃和35℃高温下轮虫生长繁殖变快, 世代时间缩短。在高温(30℃和35℃)环境下, 铜绿微囊藻浓度升高对轮虫抑制作用更加明显。

EFFECTS OF TEMPERATURES AND MICROCYSTIS AERUGINOSA TOXICITY ON LIFE-TABLE PARAMETERS OF BRACHIONUS CALYCIFLORUS

To investigate the effects of two strains of Microcystis aeruginosa (microcystin-producing and microcystin-free) at different concentrations on the life table parameters of Brachionus calyciflorus, we conducted a life-table study at 25℃ and investigated the responses of life table parameters of B. calyciflorus to microcystin-producing M. aeruginosa concentrations at five temperature gradients. The results showed that both M. aeruginosa toxicity and concentration significantly mediated the net reproduction rate (R₀; F=31.83, P<0.01; F=30.36, P<0.01) and intrinsic growth rate (r_m; F=34.67, P<0.01; F=18.73, P<0.01) of B. calyciflorus with a significant interactive effect, and that temperature and microcystin-producing M. aeruginosa concentration had significant independent and interactive effects on the net reproduction rate (R₀; F=13.51, P<0.01) and intrinsic growth rate (r_m; F=12.99, P<0.01) of B. calyciflorus. Microcystin-free M. aeruginosa promoted the rotifer population and it could be used as a food source for rotifers at low concentration (1×104 cells/mL), but its food quality was low due to the lack of fatty acids and other nutrients. High concentration of Microcystin-free M. aeruginosa (1×105 cells/mL and 5×105 cells/mL) obviously inhibited the growth of rotifers because rotifers prefer microcystin-free M. aeruginosa. The net reproductive rate and intrinsic growth rate of B. calyciflorus increased significantly by increasing concentration of microcystin-producing M. aeruginosa. Moreover, high temperature (30℃ and 35℃) accelerated their reproduction and growth rate, shorten the generation time, and promoted inhibitory effect of microcystin-free M. aeruginosa on rotifers.