【作者】 刘莹；

【导师】 吴小平；

【作者基本信息】 南昌大学 ， 动物学， 2006， 硕士

【摘要】 本文通过室内实验研究了铜绿微囊藻PCC7820对1种大型枝角类、2种小型枝角类和2种双壳类的毒性影响。 大型枝角类蚤状溞的滤食实验结果表明，有毒微囊藻PCC7820可降低蚤状溞的存活率、种群增长率和个体生长速度。而且，随着实验温度的升高(从20℃到30℃)，微囊藻PCC7820的毒性作用显著增强。研究还发现，在食物中添加栅藻能显著降低微囊藻PCC7820对蚤状溞的毒性作用，且栅藻的比例越高，降低微囊藻毒性作用就越强。这表明在自然水体中浮游动物不仅仅受有毒蓝藻的影响(毒素含量和有毒蓝藻的丰度)还受水体中绿藻丰度的影响。 小型枝角类微型裸腹溞和角突网纹溞的滤食实验结果显示，有毒微囊藻可降低这两种动物的种群存活率，其大小顺序均为：无毒微囊藻处理＞饥饿处理＞有毒微囊藻处理。裸腹溞对饥饿和微囊藻的敏感性高于网纹溞。有毒微囊藻还可抑制这两种枝角类的滤食率。同样，在食物中添加栅藻能显著降低微囊藻PCC7820的毒性作用，两种枝角类的种群增长率都显著提高。 淡水贝类圆顶珠蚌及河蚬的滤食实验结果显示，这两种贝类对食物的反应不一致。圆顶珠蚌对栅藻、有毒、无毒微囊藻的滤食率无显著差异，而河蚬对有毒微囊藻的滤食率要显著低于对栅藻和无毒微囊藻的滤食率。在栅藻和微囊藻混合情况下，两种贝类的滤食率都要高于单一藻类情况下的滤食率。在两种贝类的排泄物(粪便和假粪便)中主要是栅藻，排泄物中栅藻／微囊藻要高于食物中两者的比例，可见两种贝类都更偏好于滤食、吸收微囊藻。综合上述实验结果，我们认为有毒微囊藻可对其滤食者产生显著的毒性影响，且其毒性强度受水体温度和绿藻丰度的影响。更多还原

【Abstract】 The toxic influences of Microcystis aeruginosa PCC7820 on three cladoceran species and two bivalves were studied through laboratory experiments.Toxic M. aeruginosa PCC7820 not only decreased the survival rate and population increase rate but also delayed maturation of Daphnia pulex. A rise of the experimental temperature from 20°C to 30°C caused an obvious increase in the toxicity of M. aeruginosa PCC7820 to D. pulex. Population increase rate of A pulex significantly increased when good quality food (Scenedesmus obliquus) was added to toxic M. aeruginosa PCC7820. The present results suggest that zooplankton community in a natural bloom may be affected not only by toxic cyanobacteria (toxin level and abundance of toxic algae) but also by the abundance of edible algae.M. aeruginosa PCC7820 decreased the survival rate of the two small cladocerans Moina micrura and Ceriodaphnia cornuta. The survival rates were in the order of non-toxic M. aeruginosa > starved > toxic M. aeruginosa. M. micrura was more sensitive to M. aeruginosa PCC7820 and starvation than C. cornuta. M. aeruginosa inhibited the feeding rates of the two cladocerans. S. obliquus significantly reduced the toxicity of M. aeruginosa PCC7820. Population of both cladocerans significantly increased when Scenedesmus obliquus was added to the food.When S. obliquus, toxic and non-toxic M. aeruginosa were offered as single food to Unio douglasiae, there was no significant difference in clearance rate, but the clearance rate of Corbicula fluminea on toxic M. aeruginosa was significantly lower than that on the other two algae. Clearance rates of both two bivalves were higher on mixed food than on single food. The excretion products (faeces and pseudofaeces) of two bivalves contained mainly S. obliquus. The ratio of S. obliquus to M. aeruginosa in both mixed-food treatments increased in the excrete products of both bivalves, compared with the ratio of these phytoplankton species in the food. It seems that both bivalves prefered M. aeruginosa to S. obliquus.In conclusion, toxic M. aeruginosa PCC7820 exerted significant toxic effects on更多还原