浙江省义乌市岩口水库鱼类群落多样性分析及鲢、鳙生长特性研究

为了解义乌市岩口水库鱼类资源现状、群落结构特征及主要鱼类的生长特性,2013年3月、5月、7月、9月和11月对水库鱼类资源进行了系统调查。共采集鱼类样本452尾,经鉴定属于37种,隶属5目8科。其中,鲤形目28种,占总数的75.7%;鲇形目5种,占总数的13.5%;鲈形目2种,占总数的5.4%;鲑形目和合鳃目各1种,分别占总数的2.7%。生态类型组成分析结果显示,以肉、杂食性鱼类为主。群落优势度分析发现,全年优势种有5种,分别为鳙、鲢、伍氏半、圆吻鲴和翘嘴鲌。生物多样性指数分析表明,鱼类种群丰富度指数(D)值变化范围为2.09~6.05,Shannon-Wiener多样度指数(H')变化范围为0.87~1.42,种类均匀度指数(J')变化范围为0.41~0.92。同时,构建了鲢、鳙生长模型:鲢的全长、体重生长方程分别为:L(t+0.136)0.265(t+0.136)t=73.5911-e-0.265],Wt=5.9111-e-]2.812,鳙的全长、体重生长方程分别为:L 0.318(t+0.12)t=73.2561-e-],Wt=7.6251-e-0.319(t+0.012)]3.070。通过分析鲢、鳙生长情况,发现岩口水库鲢、鳙体长增长速度以1~4龄较高,4龄以后逐渐降低,鲢、鳙体长生长拐点分别为3.759龄和3.327龄,为使鲢、鳙鱼最大程度地发挥洁水保水功效,建议鲢、鳙的起捕年龄为5龄。

Study on the diversity of fish community structure and growth performance of Hypophthalmichthys molitrix and Aristichthys nobilis in Yankou Reservoir, Zhejiang Province

The investigation on fish resources in Yankou reservoir was carried out in March, May, July, September, November 2013 separately, in order to reveal the characterization of fish community, resources status and growth performance of main fish species.452 fish specimens were measured and identified, which belonged to 5 orders,8 families and 37 species.Cyprinidae was the largest order,which accounted for 75.7% . Siluriformes accounted for 13.5%, and Perciformes accounted for 5.4%. Salmoniformes and synbranchiformes accounted for 2.7%,respectively.The ecological type analysis revealed that the community was dominated by carnivorous and omnivorous fish. There were 5 dominant fishes by analyzing the index of relative importance, which were Hypophthalmichthys molitrix, Aristichthys nobilis, Hemiculterlla wui, Culter alburnus and Distoechodon tumirostris. Three diversity indexes including species richness index(D),Shannon-Wiener index(H') and species evenness index(J') were used to analyze diversity characteristics of the fish community. And the values of D,H' and J' varied from 2.09 to 6.05,0.87 to 1.42 and 0.41 to 0.92 respectively.The growth equation of body length and weight for H. molitrix were L_t=73.5911-e^{-0.265(t+0.136)}] and W_t=5.9111-e^{-0.265(t+0.136)}]^2.812, respectively; and for A.nobilis were L_t=73.2561-e^{-0.318(t+0.12)}]and W_t=7.6251-e^{-0.319(t+0.012)}]^3.07, respectively. In Yankou reservoir, Hypophthalmichthys molitrix and Aristichthys nobilis grew relatively fast from 1 to 4 years, and their inflecting point were 3.795 and 3.327,respectively. The most appropriate catching age was 5 years for the two aquatic environmental protection oriented fishes in order to get the best effect on algal bloom control and economic benefit.