【摘要】 以萼花臂尾轮虫（Brachionus calyciflorus）为受试动物,在1.0×10⁶（较低）、2.0×10⁶（中等）和4.0×10⁶个细胞/mL（较高）的斜生栅藻（Scenedesmus obliquus）密度下,研究了不同浓度（0、200、400、600、800和1000μg/L）的青霉素钠对轮虫各生命表统计学参数的影响。结果表明,与各藻密度下的对照组相比,当藻密度为2.0×10⁶个细胞/mL时,200—1000μg/L的青霉素钠处理组中轮虫的生命期望和世代时间分别延长了40.67%—70.67%和34.04%—50.23%（P<0.05）,净生殖率和内禀增长率分别提高了204.35%—358.70%和36.26%—62.09%（P<0.05）;藻密度的降低或升高均显著降低青霉素钠对轮虫存活、生殖和种群增长的促进幅度。1.0×10⁶ 个细胞/mL的斜生栅藻密度下,400μg/L的青霉素钠处理组中轮虫的生命期望延长了21%（P<0.05）,200—400μg/L的青霉素钠处理组中轮虫的世代时间延长了23.15%—33.13%（P<0.05）,200—600和1000μg/L的青霉素钠处理组中轮虫的净生殖率分别升高了40%—81.05%和41.05%（P<0.05）;但4.0×10⁶个细胞/mL的斜生栅藻密度下,各青霉素钠处理组中轮虫的所有生命表统计学参数均与对照组之间无显著性差异（P>0.05）。藻密度对轮虫的生命期望、净生殖率、内禀增长率和后代混交率均具有显著性影响（P<0.01）,青霉素钠浓度对轮虫的世代时间、净生殖率和内禀增长率均具有显著性影响（P<0.05）,藻密度和青霉素钠浓度的交互作用对轮虫的生命期望、净生殖率和内禀增长率也具有显著性影响（P<0.05）。在实验设置的青霉素钠浓度范围内,1.0×10⁶个细胞/mL藻密度下轮虫的生命期望、世代时间和净生殖率与青霉素钠浓度之间均具有显著的剂量—效应关系（P<0.05）;2.0×10⁶个细胞/mL藻密度下,轮虫的生命期望、世代时间和内禀增长率与青霉素钠浓度之间均具有显著的剂量—效应关系（P<0.05）。本研究结果提示,环境相关浓度的青霉素钠不会对萼花臂尾轮虫的存活、生殖和种群增长产生显著性影响。更多还原

【Abstract】 Antibiotics are commonly used in human medicine and animal husbandry for the prevention and treatment of illnesses and the promotion of growth. Due to high consumption, incomplete metabolism and continuous discharge, antibiotics are frequently detected in the aquatic environment. Resistant bacteria and genes caused by antibiotics are receiving considerable attention, but the sublethal effects of antibiotics on the non-target organisms, especially the aquatic organisms, should be taken into consideration, due to their important role in aquatic ecosystems and their potential sensitivity to contaminants. In order to understand the chronic toxicity of antibiotics to aquatic organisms under different algal food densities, the freshwater rotifer Brachinionus calyciflorus was used as test animal to investigate the effects of penicillin sodium concentrations（0, 200, 400, 600, 800 and 1000 μg/L） on its life-table demographic parameters under three levels（1.0×10⁶, 2.0×10⁶ and 4.0×10⁶ cells/mL） of Scenedesmus obliquus. The results showed that compared to the control under each algal density, and when the algal density was 2.0×10⁶ cells/mL, treatments with penicillin sodium at 200—1000 μg/L prolonged life expectancy at hatching and generation time by 40.67%—70.67% and 34.04%—50.23%, and increased net reproductive rate and intrinsic rate of population increase of the rotifers by 204.35%—358.70% and 36.26%—62.09%, respectively（P<0.05）. Both increase and decrease in algal density decreased the magnitudes of promoting effects of penicillin sodium on survival, reproduction and population growth of the rotifers. At 1.0×10⁶ cells/mL of S. obliquus, treatment with penicillin sodium at 400 μg/L prolonged the life expectancy at hatching by 21%, treatments with penicillin sodium at 200—400 μg/L prolonged the generation time by 23.15%—33.13%, and those at 200—600 and 1000 μg/L increased the net reproductive rate by 40%—81.05% and 41.05%, respectively（P<0.05）. At 4.0×10⁶ cells/mL of S. obliquus, however, penicillin sodium concentration did not affect any life-table demographic parameters of the rotifers（P>0.05）. In the range of tested penicillin sodium concentrations, and at 1.0×10⁶ cells/mL of S. obliquus, significant effect-dose relationships were observed between life expectancy at hatching, generation time as well as net reproductive rate and penicillin sodium concentration, and could be described as y=-6.07×10^-5x² +0.098x+ 62.629, y=-4.10×10^-5x²+ 0.041x+52.55, and y=-2.640×10^-5x²+ 0.042x+ 5.238, respectively. At 2.0×10⁶ cells/mL of S. obliquus, significant effect-dose relationships were observed between life expectancy at hatching, generation time as well as intrinsic rate of population increase and penicillin sodium concentration, and could be described as y=-6.187x² +0.098x+ 51.464, y=-3.821×10^-5x² +0.054x+ 45.679, and y=-4.389×10^-8x²+6.417×10^-5x+ 0.037, respectively. The present results indicated that penicillin sodium at environmental relevant concentrations would not significantly affect the survival, reproduction and population growth of rotifers.更多还原