大型溞与富营养化水体中藻类的相互作用研究

为研究典型浮游动物大型溞(Daphnia magna)对富营养化水体中藻类的牧食生态关系,选取有毒藻和无毒藻富营养化水体水样,分析测试藻类与大型溞的相互作用。结果表明,有毒藻水样对大型溞的生长繁殖产生极大负面影响,在有毒藻水样原液中大型溞体长最大仅为1.18mm,仅为无毒藻水样对照组大型溞最大体长的52.91%,且最长寿命仅为13d,明显低于对照组的45d。无毒藻水样对照组中大型溞累积产幼量为71个,随着有毒藻浓度的上升大型溞产幼量逐渐下降,在高浓度有毒藻水样下完全丧失繁殖能力。在较低浓度有毒藻水样中,大型溞表现出对有毒藻的抗性,基本能够正常生长繁殖,24h藻类去除率达到45.61%。研究表明在有毒藻浓度较低的条件下,虽然大型溞的生长繁殖受到一定抑制作用,但大型溞还能够维持种群的生存繁衍,对藻类维持足够的摄食压力,可有效控制藻密度。

Study on the interaction between Daphnia magna and algae in eutrophic water

In order to study the relationship between Daphnia magna and algae in eutrophic water,water samples containing toxic algae and non-toxic algae were selected to analyze the interaction between Daphnia magna and algae. The results showed that toxic algae had significant negative effect on the growth and reproduction of Daphnia magna . The maximum length of Daphnia magna in toxic algae water was only1.18 mm,which was only 52.91% of the maximum length of Daphnia magna in non-toxic algae water,and the longest life span was only13 days,significantly lower than 45 days in control group. The cumulative offspring yield of Daphne magna in the control group was 71. With the increase of concentration of toxic algae,the offspring yield gradually decreased,and the reproductive capacity of Daphnia Magna was completely lost in high concentration toxic algae water. In low concentration toxic algae water, Daphnia magna showed resistance to toxic algae,and could basically grow and reproduce normally. The algae removal rate reached 45.61% in24 hours. The results showed that although the growth and reproduction of Daphnia magna were inhibited under the condition of low toxic algae concentration, Daphnia magna could maintain the survival and reproduction of the population,maintain sufficient feeding pressure on algae,and effectively control the algae density.