池塘主养草鱼三种养殖模式浮游植物群落结构的比较

2010年6-10月,在湖北省武汉市新洲区少潭河水库坝下陆基鱼池对主养草鱼(Ctenopharyngodon idellus)池塘三种混养模式(模式Ⅰ,草鱼、鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)和鲫(Carassius auratus)分别放养250、35、40和15尾;模式Ⅱ,草鱼、鲢、鳙、匙吻鲟(Polyodon spathula)和鲫分别为250、35、20、20和15尾;模式Ⅲ,草鱼、鲢和鲫分别为250、35和15尾)浮游植物进行了比较研究。结果显示:共检出浮游植物8门118属279种,其中,蓝藻门20属29种、绿藻门63属137种、硅藻门20属59种、裸藻门7属45种、金藻门3属3种、隐藻门2属3种、黄藻门2属2种以及甲藻门1属1种。浮游植物平均密度分别为7.66×107、6.95×107、6.74×107ind./L;平均生物量分别为70.71、62.12、85.52 mg/L;模式Ⅱ的Shannon-Wiener多样性指数和Pielou均匀度指数随着养殖时间均呈上升趋势,并在9月时处于三个模式中的最高水平,说明模式Ⅱ的浮游植物群落结构越来越稳定,处于一种更好的发展状态。

Comparison on phytoplankton community structures in three pond polyculture modes with Ctenopharyngodon idellusas dominant stocking species

During June to October,2010,phytoplankton community structures were compared in three pond polyculture modes with Ctenopharyngodon idellus as dominant stocking species(ModeⅠ,250 C.idellus,35 Hypophthalmichthys molitrix,40 Aristichthys nobilis and 15 Carassius auratus;ModeⅡ,250 C.idellus,35 H.molitrix,20 A.nobilis,20 Polyodon spathula and 15 C.auratus;model Ⅲ,250 C.idellus,35 H.molitrix,and 15 C.auratus).These experiments were carried out in land-based fish ponds,which located at aquaculture base of Shaotanhe Reservoir,Wuhan city,Hubei province.According to the result,the phytoplankton assemblage was composed of 279 species in total,belonging to 118 genera,8 phyla which were Cyanophyta(29 species,20 genera),Chlorophyta(137 species,63 genera),Bacillariophyta(59 species,20 genera),Euglenophyta(45 species,7 genera),Chrysophyta(3 species,3 genera),Cryptophyta(3 species,2 genera),Xanthophyta(2 species,2 genera),and Pyrrophyta(1 species,1 genera).The phytoplankton density averaged 7.66×107 ind./L,6.95×107 ind./L and 6.74×107 ind./L,respectively.The phytoplankton biomass averaged 70.71 mg/L,62.12 mg/L and 85.52 mg/L,respectively.Comparing the phytoplankton community diversity in three culture modes,we found that the Shannon-Wiener diversity index and Pielou evenness index of phytoplankton community in Mode Ⅱ increased gradually as culture time went on,and the highest level appeared in September in all the three modes.The results showed that the phytoplankton community of Mode Ⅱ was more stable and in a better development state.