【作者】 张小谷；

【导师】 熊邦喜；

【作者基本信息】 华中农业大学 ， 水产养殖， 2008， 博士

【摘要】 鄱阳湖（Lake Poyang）位于长江中下游南岸，东经115°49’-116°46’，北纬28°24’-29°46’，是我国第一大淡水湖，汇纳赣江、抚河、信江、饶河、修水，于湖口注入长江，鱼类资源丰富。鲌是我国淡水常见肉食性鱼类，主要以小型鱼虾为食，具有较高的经济价值，对鄱阳湖鲌资源研究和利用具有十分重要的意义。目前，有关鄱阳湖鲌种群研究的报道较少。因此，本研究运用形态度量学和几何形态学方法，对鄱阳湖分布的翘嘴鲌（Culter alburnus）、蒙古鲌（C.mongolicus）、达氏鲌（C.dabryi）和红鳍原鲌（Cultrichthys erythropterus）体形、脑形态及生长特性进行比较研究，探讨鲌形态差异及资源利用状况，对蒙古鲌进行体形、鳃弓、鳞片形态多样性研究，推测鄱阳湖鱼类种群形态分离事件。本研究得到的主要结果如下：1、对633尾鲌分别按4个体长段分组，共16个组别，选取13个特征点运用Tps几何形态分析系列软件和STATISTICA 6．0统计软件进行体形比较分析。结果表明，4种鲌种间差异大于同种鲌不同生长时期间的差异。鲌生长过程中体形变化在翘嘴鲌、蒙古鲌、达氏鲌表现为头部和尾部长度增长相对较慢，达氏鲌在头后部至背鳍后体高增长速度快，增长幅度大，致使达氏鲌在头后部显著隆起成为物种区分的主要特征之一，红鳍原鲌随着体长的增长体高相对体长的增加幅度较小，躯干后部在体长处150mm至250mm时长度和高度增长较明显。2、选择48尾鲌标本，以Motic Images Advanced 3．2软件对脑21个形态性状进行度量，同时对34个特征点进行几何形态分析。形态度量和几何形态方法均表明，鲌属和原鲌属鱼类在小脑形态和嗅束长等方面差异明显，翘嘴鲌、蒙古鲌、达氏鲌的脑形态差异表现在小脑、端脑、中脑等各部分的细微差异。3、对采集于7个样本点的蒙古鲌，选取14个传统测量特征值、24个框架结构度量特征值进行测量，13个特征点进行几何形态分析。结果表明，鄱阳湖7个蒙古鲌样本可分为2个样本组，它们是：（1）鄱阳湖波阳水域+溪口湖+南北港+谷山湖；（2）鄱阳湖都昌水域+鄱阳湖星子水域+新妙湖。第一样本组可进一步区分为2个亚样本组，即“鄱阳湖波阳水域+溪口湖+南北港”亚样本组和“谷山湖”亚样本组，其中“谷山湖”亚样本组更接近于第二样本组，“鄱阳湖波阳水域+溪口湖+南北港”亚样本组内，“南北港”样本更接近于“谷山湖”亚样本组。鱼体高度（如头高、体高、尾部高度），头长（特别是吻长），眼的相对位置等是鄱阳湖7个蒙古鲌样本组群的主要差异特征。这一样本形态分离不是按人工大坝的位置区分的，根据采样点的地理纬度可能应联系到一些河流与鄱阳湖连通的位置，如南部的抚河、信江、昌江、饶河，中部的赣江、修河，北部的长江。选择南北港、新妙湖和溪口湖样本进行鳃耙计数、鳃弓和鳞片度量，建立鳃弓测量值与体长回归方程，进行判别函数分析，计算鳞片的6个形态因子和5个形态指数，并进行ANOVA显著性分析和主成分分析。蒙古鲌3个样本在鳃弓和鳞片形态上存在形态多样性，可以认为是种群分离或区分为不同种群。南北港和溪口湖样本鳃弓和鳞片形态相近。4、对4种鲌分别进行生长特性研究，翘嘴鲌、蒙古鲌、达氏鲌、红鳍原鲌样本年龄范围分别是0⁺-4、0⁺-5、0⁺-7、0⁺-6，比率较大的年龄段分别为0⁺-1（65．9％）、2⁺-3（33．1％）、1⁺-2（29．1％）、2⁺-3（32．2％）。鲌体长生长与鳞片生长呈正比关系，4种鲌体长与鳞径的回归方程分别为：翘嘴鲌L=10．4399+100．1273×SR、蒙古鲌L=52．8778+65．4337×SR、达氏鲌L=76．3400+43．1301×SR、红鳍原鲌L=40．0273+48．1733×SR。鲌生长可看作等距生长，4种鲌体长与体重的回归方程分别为：翘嘴鲌W=6．3×10^-6L^3．1054、蒙古鲌W=8．08015×10^-6L^3．0893、达氏鲌W=2．5×10^-6L^3．3319、红鳍原鲌W=3．1×10^-6L^3．2975。体重与体侧面积体厚的回归方程在反映体重与体维关系上较适宜，4种鲌体重-体侧面积体厚之间幂函数关系分别为：翘嘴鲌W=4．05051×10^-3×A^0．66260×T^1.41994、蒙古鲌W=3．18603×10^-3×A^0．66845×T^1.44376、达氏鲌W=1．99310×10^-3×A^0．70982×T^1.47305、红鳍原鲌W=3．58823×10^-3×A^0．63253×T^1.49465。5、4种鲌的体长生长方程、体重生长方程、渐近体长、渐近体重、拐点年龄、拐点时体长、体重分别为：翘嘴鲌Lt=872．04×[1．e^{-0．1667×（t+0．161）}]、Wt=8528．64×[1-e^{-0.1667×（t+0．161）}]^3．1054、L_∞=872．04mm、W_∞=8528．64g、6．96龄、L_t=606．08mm、W_t=2755．59g；蒙古鲌L_t=568．8247×[1．e^{-0.1856×（t+0．1634）}]、W_t=2620．4407×[1-e^{-0．1856×（t+0．1634）}]^3．0893、L_∞=568．82mm、W_∞=2620．44g、6．24龄、L_t=395．53mm、W_t=852．90g；达氏鲌Lt=353．6449×[1-e^{-0.2218×（t+0.6582）}]、Wt=775．3749×[1-e^{-0.2218×（t+0．6582）}]^3．3319、L_∞=353．64mm、W_∞=775．37g、6．08龄、L_t=274．30mm、W_t=332．54g；红鳍原鲌Lt=327．3487×[1-e^{-0．2112×（t+1．0745）}]、Wt=-608．9887×[1-e^{-0.2112×（t+1．0745）}]^3.2975、L_∞=327．35mm、W_∞=608．99g、4．57龄、L_t=228．08mm、W_t=184．98g。鄱阳湖鲌种群在天然渔业及对野杂鱼控制上具有一定的经济意义，种群控制适当。6、运用形态度量和几何形态分析检测鱼自属（Culter）9个种和亚种517尾标本，分析表明兴凯鲌（Culter dabryi shinkainensis Yih et Chu，1959）应从亚种水平提升到物种水平，也就是兴凯鲌（C.shinkainensis Yih et Chu，1959）。翘嘴鲌东北亚种[Erythroculter ilishaeformis sungarinensis Yih et Chu，1959（E.ilishaeformis=C．alburnus）]与翘嘴鲌其它种群在形态区分上有着显著差异，但它们间的差异应属不同地理种群水平上的差异，而不是亚种水平。更多还原

【Abstract】 Poyang Lake, China’s biggest freshwater lake, locates on the south riverside of the middle and lower reaches of Yangtze River （28°24’-29°46’N, 115°49’-116°46’E）. The lake lies at the convergence of 5 rivers, such as Ganjiang River, Fuhe River, Xinhe River, Raohe River and Xiushui River, and helps regulate water in the Yangtze River by providing water through Hukou County. The fish resource in Poyang Lake is abundant. Culters is a popular and important economical carnivorous freshwater fish in China which feeds on small fish and shrimp. It is important to study and exploit the resource of Culter in Poyang Lake, however, little information is available about this field. Therefore, studies focused on the Culter population in Poyang Lake are meaningful.In the present study, we analyzed the differences of the body shape, brain shape, and growth characteristics among Culter alburnus, C. mongolicus, C. dabryi and Cultrichthys erythropterus, the diversities of body shape, gill arch and scale of C. mongolicus, and discussed the events about the morphometric separation of fish population in Poyang Lake. The results are shown as follows:1. A total of 633 samples of Culter were assigned into 16 groups according to 4 body length zone. 13 landmarks were used for geometric morphometric analysis of body shape through TPS Program and STATISTICA Program Version 6.0. The results showed the diversities of body shape among four species are more than among the growth phases. The changes of body shape depends on the slow growth of head length and caudal length in Culter alburnus, C. mongolicus, and C. dabryi, the distinct growth of the back of the body behind head as one of main characters in C. dabryi, the slow growth of body depth than standard length, but in the stage of standard length which between 150mm- 250mm, the obvious growth of the length and depth of the later trunk region in Cultrichthys erythropterus.2. The brain shape data were collected from 48 samples. 21 brain morphological characters were measured by using Motic Images Advanced Program Version 3.2, and 34 landmarks were used in geometric morphometrics analysis. There were the distinctions on shape of the cerebellum and length of the tractus olfactorius between genus Culter and genus Cultrichthys. The morphological differences of brain among Culter alburnus, C. mongolicus, and C. dabryi showed as the subtle differences in each brain section. 3. A total of 126 Culter mongolicus Basilewsky were collected from 7 different sampling points. 14 traditional eigenvalues and 24 truss-based eigenvalues were measured. 13 landmarks were used for geometric morphometfic analysis. The multivariate discriminant function analysis and cluster analysis showed that there were significant differences in the body shape among 7 groups. In the region of the Lake Poyang, 7 groups should be divided into two sample-groups in the present study. They were: （1） PYH 1 + XKH + NBG + GSH. （2） PYH 2 + PYH 3 + XMH. Furthermore, first sample-group could be divided into two inferior sample-groups, PYH 1 + XKH + NBG sub-sample-group and GSH sub-sample-group. GSH sub-sample-group was more close to the second sample-group. Within PYH 1 + XKH + NBG sub-sample-group, NBG closes more near to GSH sub-sample-group than PYH 1 + XKH. The depths, such as head depth, body depth and caudal depth, and head length, especially snout length, and the eyes’ relative position were related to the different characters among the 7 geographical groups. They are scattered in the order of the geographical latitude but not of the artificial dams’ position. The populations of C. mongolicus in the Poyang Lake could be related to the sites of connection with some rivers, for example, Fuhe River, Xinjiang River, Changjiang River, the south of Raohe River, the middle of Ganjiang River and Xiuhe River , and the north of Yangtze River. The specimens, from NBG, XMH and XKH, were used for gill arch and scale morphometric analysis. The regression equations for standard length and the measurements of gill arch, such as gill-arch length, number of gill-raker, gill-raker length, mean gill-raker width, and mean gill-raker spacing, and 6 shape factors and 5 shape indices of scale were calculated. ANOVA, principal components analysis and discriminant function analysis showed that there were significant differences in the gill arch and the scale among 3 groups, and more similar between NBG and XKH. We thought there are two or more populations of C. mongolicus in Lake Poyang.4. All specimens, 232 Culter alburnus, 169 C. mongolicus, 79 C. dabryi and 121 Culterichthys erythropterus were collected from Lake Poyang and the age divided into 0⁺-4、0⁺-5、0⁺-7、0⁺-6 age groups. The higher percentage of the samples’ age ranges were 0⁺-l （65.9%） ,2⁺-3 （33.1%） ,1⁺-2 （29.1%） , 2⁺-3 （32.2%） . The results showed that the scale-radium takes on linear relationship with standard length, L=10.4399+100.1273×SR, L=52.8778+65.4337×SR, L=76.3400+43.1301×SR,L=40.0273+48.1733×5R. The regression equation for standard length and body weight is W=6.3×10^-6L^3.1054, W=8.08015×10^-6L^3.0893, W=2.5×10^-6L^3.3319, W=3.1×10^-6L^3.2975, and growths of them take on a constant speed style. The regression equations for body weight, side area and width are feasible. In the present study, the power equations the can give better results are W=4.05051×100^-2×A^0.66260×T^1.41994, W=3.18603×10^-3×^0.66845×T^1.44376, W=1.99310×10^-3×A^0.70982×T^1.47305, and W=3.58823×10^-3×A^0.63253×T^1.494655. Growths of four species of Culter can be described with von Bertalanffy equations, namely standard length growth equation, body weight growth equation, body weight growth inflexion point, and with the corresponding standard length and body weight:C. alburnus: Lt=872.04×[1-e^{-0.1667×（t+0.161）}], Wt=8528.64×[1-e^{-0.1667×（t+0.161）}]^3.1054, inflexionpoint 6.96 age, Lt=606.08mm、W_t=2755.59g; C.mongolicus:L_t=568.8247×[1-e^{-0.1856×（t+0.1634）}], W_t=2620.4407×[1-e^{-.1856×（t+0.1634）}]^3.0893,inflexion point 6.24 age, L_t=395.53mm, W_t=852.90g; C. dabryi: Lt=353.6449×[1-e^{-0.2218×（t+0.6582）}], Wt=775.3749×[1-e^{-0.2218×（t+0.6582）}]^3.3319,inflexion point 6.08 age, L_t=274.30mm, W_t=332.54g; C.erythropterus::t=327.3487×[1-e⁽-0.2112×（t+1.0745）],Wt=608.9887×[1-e^{-0.2112×（t+1.0745）}]^3.2975,inflexion point 4.57 age, L_t=228.08mm, W_t=184.98g.6. A total of 517 specimens of genus Culter, 235 C. alburnus were collectd from different localities and were used for morphometric analysis. The results of discriminant analysis and cluster analysis indicated that four species-groups could be divided. C. dabryi shinkainensis was significantly different from C. dabryi dabryi in body forms, so C. dabryi shinkainensis should be changed to species, instead of subspecies, namely Culter shinkainensis （Yih et Chu）, 1959. The 6 populations of C. alburnus （Basilewsky）, from Lake Poyang, River Songhua, River Liaohe, River Jialing, River Lijiang and Lake Taihu, should be classified as different geographical populations, but not subspecies.更多还原