【作者】 田辉伍；

【导师】 陈大庆；

【作者基本信息】 华中农业大学 ， 渔业资源， 2010， 硕士

【摘要】 本文基于形态特征、年龄、生长、食性、繁殖、种群现状及种群动态等方面对2006年—2008年采自怒江的后鳍吻孔鳃(Poropuntius opisthopterus)和保山新光唇鱼(Neolissochlus wynaadensis)进行了比较研究,主要研究结论如下：1、形态特征：Fisher逐步判别分析结果表明两种鱼类在侧线鳞数、背鳍前鳞数、围身体鳞数、尾柄长／尾柄高、背鳍前距／背鳍后距等方面有显著差异(P<0.01)。结果显示从形态特征上可以区分后鳍吻孔鲃和保山新光唇鱼；2、年龄与生长：两种鱼类均采用耳石为最终年龄鉴定材料,脊椎骨和鳞片为辅助鉴定材料。样本中后鳍吻孔鳃由1～11龄11个年龄组组成,体长50～350mm,体重2.1～1900.0g,保山新光唇鱼由2～10龄9个年龄组组成,体长72～455mm,体重6.6～2750.5g。两种鱼类均具生长速度较慢、L∞值相对较大和拐点年龄较高的共同特性,由退算体长估算出的von Bertalanffy生长参数分别为：后鳍吻孔鲃L∞=497.66mm,k=0.117/年,t0=0.571年,ti=10.79年；保山新光唇鱼L∞=667.95mm,k=0.120/年,t0=0.783年,ti=10.65年；3、食性特征：两种鱼类消化系统结构相似,食物中以底栖无脊椎动物为主(重量指数%W>60%),兼有植物碎片、落水昆虫和浮游植物等,其中有13种饵料生物相互重叠。饵料生物中的无脊椎动物大多属于营底栖或中下层自游泳生活的生物类群。初步判定后鳍吻孔鳃和保山新光唇鱼为食底栖无脊椎动物鱼类；4、繁殖特征：两种鱼类性比分别为后鳍吻孔鳃1：1.59,保山新光唇鱼1：1.73。最小性成熟个体体长分别为后鳍吻孔鳃177mm,相应年龄为4.32龄,保山新光唇鱼为230mm,相应年龄为4.29龄；5月为两种鱼类的繁殖高峰期,属一次性产卵类型鱼类,成熟卵径分别为1.33±0.17mm和1.35±0.20mm；相对怀卵量分别为后鳍吻孔鳃24.68±9.36粒/g,保山新光唇鱼17.99±3.73粒/g；5、种群现状及种群动态：以20种已知生活史类型鱼类为参照物,判断两种鱼类均为偏k选择型鱼类；根据体长股分析(LCA)模型,2006-2008年后鳍吻孔鳃和保山新光唇鱼的年平均资源量为6.58×104kg和8.03×104kg,对应年平均资源数量为0.76×106尾和0.29×106尾。根据B—H动态综合模型,两种鱼类当前开发率(Ecur)均高于最佳渔业开发率(Emax),且当前渔业点Ecur和Lc/L∞均位于渔获量等值曲线的D象限,评估结果显示两种鱼类均处于过度利用状态。建议降低捕捞强度,提高捕捞规格,以保证两种鱼类资源的可持续利用。更多还原

【Abstract】 Comparative study on the morphological characters, age, growth, feeding habits, reproduction and population dynamics of Poropuntius opisthopterus and Neolissochlus wynaadensis was catched in the Nu River during 2006 to 2008 was carried out. The main findings are as follows.1. Morphological characteristic. Using the Fisher Discriminant method, statistical results showed large difference (P<0.01) between Poropuntius opisthopterus and Neolissochlus wynaadensi in the scales number of lateral line scales, scales number in front of dorsal fin, scales number around the body, the ratio of the length to the height of caudal peduncle and the ratio of the distance from the start point of the dorsal fin to the head and the distance from the start point of the dorsal fin to the start point of the caudal fin. So, it can be easily distinguished between Poropuntius opisthopterus and Neolissochlus wynaadensis from the morphological characteristics.2. Age and growth. The otoliths of Poropuntius opisthopterus and Neolissochlus wynaadensis were the main material to definite the age, and opercula and scale were used as the supplementary material. Samples collected for Poropuntius opisthopterus included 11 age groups from 1 to 11 year,50 to 350mm in body length and 2.1 to 900.0 in body weight; Samples collected for Neolissochlus wynaadensis included 9 age groups from 1 to 10 year,72 to 455mm in body length and 6.6 to 2750.5 in body weight. Poropuntius opisthopterus and Neolissochlus wynaadensis have similar growth performance as slow growth rate, relatively large value of L∞and high inflection point of the weight growth. Their von Bertalanffy growth parameters derived from back-calculated body length were as follows. For Poropuntius opisthopterus,L∞=497.66 mm, k=0.117/year,t0=0.571 year, ti=10.79 year; for Neolissochlus wynaadensi, L∞=661.95 mm, k=0.120/year, to= 0.783 year, ti=10.65 year.3. Feeding habits. The food composition of Poropuntius opisthopterus and Neolissochlus wynaadensis were similar. They mainly feed on invertebrate animals(weight percent%W>60%), plant debris, water insects and phytoplankton, and 13 species of these food overlapped. Most of invertebrate animals live in the bottom of the water or belong to the self-swimming species in middle level or lower level of the water. From above, it can be preliminary deduced that Poropuntius opisthopterus and Neolissochlus wynaadensis mainly feed on bottom invertebrate animals. 4. Reproduction. The sex ratio of Poropuntius opisthopterus and Neolissochlus wynaadensis were 1:1.59 and 1:1.73. The minimum body length and age of male individuals at first maturity of Poropuntius opisthopterus and Neolissochlus wynaadensis were 177 mm,4.32 years and 230 mm,4.29 years, respectively. The peak of spawning activity for both of them took place in May, the mean diameter of mature eggs of them were 1.33±0.17mm and 1.35±0.20mm, the mean relative fecundity of Poropuntius opisthopterus and Neolissochlus wynaadensis was 24.68±9.36 egg/g and 17.99±3.73 egg/g, respectively.5 population status and population dynamics:Compared with the life-history patterns of 20 kinds of fishes, the results showed that the life-history pattern of Poropuntius opisthopterus and Neolissochlus wynaadensis tended to be K-selection. According to length-based cohort analysis (LCA) model, during 2006 to 2008, the average annual stock biomass of Poropuntius opisthopterus and Neolissochlus wynaadensis were 6.58×104 kg and 8.03×104 kg, with the number of 0.76×106 individuals and 0.29×106 individuals respectively. According to Beverton-Holt dynamic model, the current exploitation ratio (Ecur) of Poropuntius opisthopterus and Neolissochlus wynaadensis was less than the maximum exploitation ratio (Emax), and the yield isopleths with Ecur and Lc/L∞belong to quadrant D. These results indicated that the fish stock was over-exploited. To protect the resource of two species, the fishing mortality coefficient must be reduced, and the first capture age should be put off by limiting the mesh.更多还原