虾池浮游微藻的种类组成、数量和多样性变动

报道了在集约化养虾中应用有益微生物制剂对虾池浮游微藻的影响,分析了整个养虾周期浮游微藻的种类组成、生物量、优势种及多样性指数的周期变化情况。结果表明,早期虾池浮游微藻细胞数量维持在1×103~3×103mL-1的水平,养殖中期开始呈指数增长状态,后期达到顶峰,并维持在70×103~160×103mL-1的水平,生物量比自然海区高。优势种类明显,前期为中肋骨条藻和伏氏海毛藻等硅藻类,后期则为绿球藻和栅列藻等绿藻类,水色及藻相呈良好状态,而不施加芽孢杆菌制剂的对照池则在后期出现较大比例的有害的蓝藻。虾池藻类多样性指数、均匀度指数和种类丰度均呈现前期高后期低的趋势,而优势度指数则相反,呈现前期低后期高的趋势。浮游植物的多样性指数为0.60~3.80,平均为1.88,均匀度指数为0.14~0.83,平均为0.45;种类丰度为0.80~2.46,平均为1.38;优势度指数在0.17~0.85,平均为0.41。多样性指数和均匀度均比粤东海域低,但优势度则甚高。

Species Composition, Quantity Variation and Bio-diversities of Phytoplankton in Shrimp Culture Ponds

This paper reports the results of influences of bacillus on phytoplankton in intensive shrimp ponds, analyzes the weekly variation of species composition, biomass and dominant species of phytoplankton on period of culture. The results indicate that the densities of the phytoplankton are 1×10~3～3×10~3 mL~(-1)during the early period,and increase rapidly from middle stage, and reach peak on later stage and maintain stable, densities are 70×10~3～160×10~3 mL~(-1), higher than the nature waters. There are obvious dominant species of profitable algae, which are Skeletonema costatum, Thalassiothrix frauenfeldii of diatoms during early period and Chlorococcum sp., Scenedesmus sp. of Chlorophyta at later stage. In the controlled pond, the main plankton species is Cyanobacteria of pernicious algae at later culture stage. The diversity index, evenness and species abundance are higher during early period and lower at later stage relatively, but the dominance index is the opposite. The diversity index of phytoplankton is 0.60～3.80, average is 1.88; and evenness is 0.14～0.83, average is 0.45; species abundance is 0.80～2.46, average is 1.38; dominance index is 0.17～0.85, average is 0.41. The diversity index and evenness are lower than the nature waters of east Guangdong, and dominance index is higher.