【作者】 李倩倩；

【导师】 黄鹤忠；

【作者基本信息】 苏州大学 ， 水生生物学， 2013， 硕士

【摘要】 太湖是我国五大淡水湖泊之一，为了改善太湖水质和鱼类种质资源结构，近年来太湖开展了较大规模的鱼类放流工作。本文以太湖放流的主要鱼类鲢（Hypophthalmichthys molitrix）、鳙（Aristichthys nobilis）、翘嘴鲌（Culter alburnus）、大银鱼（Protosalanx chinensis）为研究对象，通过现场调查和历史资料统计分析，取得主要研究结果如下：1、对太湖鲢、鳙、翘嘴鲌、大银鱼等的历年放流数量和渔获量统计数据分析结果显示：2008²011年间，鲢、鳙、银鱼渔获量随放流量增加而显著增加，且影响着主要鱼类的种群数量结构，太湖鲢鳙与梅鲚及银鱼渔获量间均存在着正相关关系但不显著（r=0.426, P>0.05; r=0.380, P>0.05）；翘嘴鲌与银鱼的渔获量间存在显著正相关关系（r=0.673, P<0.05），而与梅鲚渔获量间存在显著负相关关系（r=-0.560, P<0.05）。因此，太湖鲢、鳙、翘嘴鲌、大银鱼放流对优化主要鱼类的种群数量结构产生了一定作用。2、对太湖鲢、鳙食性的研究结果显示：9月份太湖鲢、鳙的肠内含物中浮游植物和浮游动物分别占食物数量的89.1%、70.6%和10.9%、29.4%，其中蓝藻分别占74.5%、56.0%。鲢、鳙对蓝藻的选择性指数分别为1.42、1.07，对轮虫和原生动物的选择性指数分别为0.13、1.27和1.30、0.40。表明太湖鲢、鳙的主要食物是蓝藻。通过对近年来鲢鳙渔获量与太湖水质理化因子间的相关分析发现，鲢鳙渔获量与TP、TN有负相关关系但不显著（r=-0.4763, P>0.05; r=-0.3679, P>0.05），与Chl.a、CODMn均表现出显著负相关关系（r=-0.7230, P<0.05; r=-0.6797, P<0.05）。因此，放流鲢、鳙对降低太湖水体的TP、TN、有机质含量以及控制蓝藻生物量具有积极作用。3、2012年5¹1月份通过对太湖鲢、鳙、翘嘴鲌、大银鱼的体长、体重生长抽样调查，得到该4种鱼的体长与体重关系式分别为：W1.510^-5L3.0488（鲢）、W3.010^-5L2.9244（鳙）、W2.010^-5L2.8819（翘嘴鲌）、W2.710^-3L3.1175（大银鱼），b值均接近3，属于均匀生长类型。该4种鱼体重快速生长的年龄拐点分别为：4.03龄（鲢）、4.29龄（鳙）、5.06龄（翘嘴鲌）、10.7月龄（大银鱼）；该4种鱼加速生长的年龄、体长、体重拐点分别为：1.73龄、27.35cm、0.36kg （鲢）；1.65龄、27.37cm、0.47kg （鳙）；1.31龄、22.07cm、0.15kg （翘嘴鲌）；3.42月龄、6.54cm、0.76g （大银鱼）。4、2012年2¹1月份对太湖国家水产种质资源保护区及其周边不同水域的环境状况初步调查结果显示：保护区水质总体状况好于其周边不同水域。保护区浮游植物、浮游动物多样性指数和均匀度分别为3.06、3.07和0.52、0.51，达到轻污染或无污染水质标准，水质营养状态指数为29.56处于贫营养状态，TN和TP含量分别为0.486±0.017mg/L和0.021±0.001mg/L，处于Ⅱ类水质标准，水生植物密度为1058.28±20.6g/m2。表明保护区为银鱼、翘嘴鲌的生长、繁殖提供了良好的水质、水草等环境条件。更多还原

【Abstract】 Taihu Lake is one of largest freshwater lakes in China, many large releasing worksin recent years have been launched to improve the water quality and the germplasmresource of fish in Taihu Lake. This paper focus primarily on the four major releasedfishes: H. molitrix, A. nobilis, C. alburnus, P. chinensis, employing field investigationand historical data, the main results as follows:1. The statistics results of historical number released and caught of H. molitrix, A.nobilis, C. alburnus, P. chinensis showed that: during2008to2011, the caught of thesefour released fishes increased significantly with the released number, and the releasednumber affect the population and structures of main fishes. The caught number of H.molitrix and A. nobilis had a positive correlation with C. ectenes and P. chinensis, butthe relationship is not significant （r=0.426, P>0.05; r=0.380, P>0.05）. The caughtnumber of C. alburnus had a significantly positive correlation with the caught numberof P. chinensis （r=0.673, P<0.05）, while the correlation between the caught numbers ofC. ectenes and C. alburnus was significantly negative （r=-0.560, P<0.05）. Therefore,the releasing of H. molitrix, A. nobilis, C. alburnus, P. chinensis has pronounced effectson optimization population and structure of the main fishes.2. The feeding habits of H. molitrix and A. nobilis in Taihu Lake were studied here,it shows that: In September, the percentages of the phytoplankton and zooplankton intotal fed quantity contained in the intestinal of H. molitrix and A. nobilis in Taihu Lakewere89.1%or70.6%and10.9%or29.4%, respectively, and the percentage ofcyanobacteria was74.5%or56%. The selective index of cyanobacteria for H. molitrixand A. nobilis was1.42or1.07, and that of cladocerans and rotifers were0.13or1.27and1.30or0.40, respectively. H. molitrix and A. nobilis feed chiefly on cyanobacteria in Taihu Lake. The analysis of the relationships between the caught number of H.molitrix and A. nobilis and physicochemical properties of the water in Taihu Lakedemonstrated that, the caught numbers of H. molitrix and A. nobilis had a negativecorrelation with TP and TN, however it not reached significant level （r=-0.4763, P>0.05;r=-0.3679, P>0.05）, indeed, it had a significantly negative correlation with Chl.a andCODMn（r=-0.7230, P<0.05; r=-0.6797, P<0.05）. So the releasing of H. molitrix and A.nobilis plays an active role in reducing the TP, TN, organic matter contents and thecyanobacteria biomass.3. From May to November in2012, the body length and body weight of the fourreleased fishes, H. molitrix, A. nobilis, C. alburnus, P. chinensis, were studied bysampling survey, the length and weight relationship of the four species wereW=1.5×10^-5L3.0488（H. molitrix）; W=3.0×10^-5L2.9244（A. nobilis）; W=2.0×10^-5L2.8819（C.alburnus）; W=2.7×10^-3L3.1175（P. chinensis）, and b value approximate to3, it indicatedthat the four species were uniform growth. The inflection point age of body weightrapid growth of the four species were4.03year old （H. molitrix）,4.29year old （A.nobilis）,5.06year old （C. alburnus）,10.7mouth old （P. chinensis）. The inflection pointage, body length, body weight of accelerated increment of the four species were:1.73year old,27.35cm,0.36kg （H. molitrix）;1.65year old,27.37cm,0.47kg （A. nobilis）;1.31year old,22.07cm,0.15kg （C. alburnus）;3.42month old,6.54cm,0.76g （P.chinensis）.4. A preliminary investigation of environmental condition of the germplasmresource protection area of Taihu Lake and its surrounding water areas had beenconducted from February to November in2012, the results showed: the water quality ofprotection area is better than that of surrounding water areas, which had reached thestandard of non-polluted or lightly-polluted levels, of which the diversity index andevenness index of phytoplankton and zooplankton were3.06or3.07and0.52or0.51respectively, furthermore, the water nutrition state index was29.56, was oligotrophic;and the concentration of TN and TP were0.486±0.017mg/L and0.021±0.001mg/L,respectively, the same as the second class of the national water quality standard;additionally, the waterweeds density was1058.28±20.6g/m2. These results might imply that the germplasm protection area of Taihu Lake give the promise of good waterquality and waterweeds condition for the growth and reproduction of C. alburnus and P.chinensis.更多还原