铜绿微囊藻对胸刺水蚤种群生长与繁殖的影响

Effect of Microcystis aeruginosa on the Reproduction and Population Growth of Copepod Centropages sp.

摘要: 目的：本文意在了解水华重要藻类之一的铜绿微囊藻是如何影响水体次级生产力重要组成之一的浮游桡足类种群生产效率的问题。本文研究了铜绿微囊藻对胸刺水蚤生长繁殖及种群增长率的影响。结果表明：铜绿微囊藻对胸刺水蚤种群的生长与繁殖的抑制作用较强，其毒性可通过抑制胸刺水蚤个体的生长、抵制卵的孵化率而降低胸刺水蚤种群增长率，并且随着铜绿微囊藻的密度增加，胸刺水蚤受到的影响也相应增加。当以有毒微囊藻为单一食物时，1.0 × 103 cells/ml浓度的铜绿微囊藻对于胸刺水蚤种群的已有较明显影响，1.2 × 104 cells/ml浓度的铜绿微囊藻对于胸刺水蚤种群的影响更为显著，而当铜绿微囊藻的密度达到1.2 × 106 cells/ml时，胸刺水蚤种群消亡快于饥饿组。同时有毒微囊藻对胸刺水蚤的毒性作用也是受一些环境因子影响，如在绿藻混合液中加入微囊藻时，铜绿微囊藻对胸刺水蚤的毒性作用有所下降，低浓度(0.5 × 103 cells/ml)的微囊藻中胸刺水蚤的种群尚能有所增长，但种群增长率低于纯绿藻组；中浓度(0.6 × 104 cells/ml)的铜绿微囊藻则显著减少桡足类的抱卵数，抑制卵的孵化率；而高低浓度(0.6 × 106 cells/ml)的铜绿微囊藻非常明显地减少桡足类的抱卵数，桡足类的孵化率也极低，且直接导致桡足类的亲体死亡。

Abstract: The effects of Microcystis aeruginosa on growth and reproduction of Centropages sp. in pure and mixed diets with green algae were examined. The experiments were conducted at three different concentrations respectively (pure diet: 1.0 × 103, 1.2 × 104 and 1.2 × 106 cells/ml; mixed diet: 0.5 × 103, 0.6 × 104 and 0.6 × 106 cells/ml). The results showed that while fed a pure diet of Microcystis aeruginosa, the growth and reproduction of Centropages sp. were significantly inhibited and the toxic effect increased with increasing concentrations. While fed a mixed diet of Microcystis aeruginosa and green algae, Centropages sp. can grow and reproduce at a lower rate compared to the control group (fed a pure diet of green algae) in the low concentration of 0.5 × 103 cells/ml. While in median or high concentration, the egg production and hatch rate of Centropages sp. were both significantly decreased.