锦江河干流黄颡鱼的年龄、生长和资源利用研究

2017年1—12月在沅江水系支流锦江河采集野生黄颡鱼样本408尾,对其生长、年龄和资源利用情况进行研究。其中,年龄结构通过对比脊椎骨、胸鳍棘、鳃盖骨、耳石,选择脊椎骨作为年龄判断材料,得到的样本年龄为1～6龄,2龄为优势年龄组,占样本总量的38.24%。体长与体质量的幂函数关系式为m=0.0001L^2.6121(r^2=0.9491,n=248);采用Von Bertalanffy生长方程拟合体长、体质量与年龄的关系,其关系式分别为L_t=210.80291-e^-0.3015(~t^+0.2272)],m_t=117.54341-e^-0.3015(~t^+0.2272)]^2.6121。生长拐点年龄为2.96龄,对应的体长130.2 mm,体质量108.2 g。采用Panly公式分析了锦江河黄颡鱼的资源利用情况,其资源开发率为0.1096,总死亡率为0.7838,自然死亡率为1.3958,当起捕体长为121 mm时,相对单位补充渔获量和生物量达到最大,分别为0.004213和0.048993,对应的年龄为2.63龄,体质量为105.2 g。当前锦江河黄颡鱼处于过度开发状态,种群明显趋于低龄化、小型化,为保护锦江河野生黄颡鱼资源,建议最小起捕体长130.2 mm,体质量108.2 g。

Age,Growth and Resources Exploitation of Yellow Catfish Pelteobagrus fulvidracoin in Principal Stream of Jinjiang River

Age structure and growth were investigated in 408 samples of yellow catfish Pelteobagrus fulvidraco collected from Jinjiang River of Guizhou from January to December in 2017 by vertebra,pectoral spine,opercula and lapillus. The yellow catfish had age from 1 to 6 years,was dominated by the 2-year-old individuals accounting for 38.24%,and had the relationship between body weight ( m ) and body length(L) was well fitted with a power function, m =0.0001 L^2.6121 (r^2 =0.9491,n=248). The Von Bertalanffy growth pattern was used to analyze the growth characteristics,and the equations among m , L and age were expressed as Lt =210.80291-e^-0.3015(t+0.2272)] and m t =117.54341-e^-0.3015(t+0.2272)] 2.6121 . Based on the lapillus radius,the inflection point of the growth curve was 2.96-year-old,with body length of 130.2 mm and body weight of 108.0 g,The natural resources of the population was discussed by classical Pauly formula,with resource development rate of 0.1096,total mortality of 0.7838 and natural mortality of 1.3958 . The peak values of relative yield-per-recruit (0.004213) and relative biomass-per-recruit ( 0.048993 ) were found when the fish was first caught at body length of 121 mm,with the corresponding age of 2.63-years and body weight of 105.2 g. The finding indicates that the yellow catfish stock was overexploited and trends to juveniles and small ones. It is suggested that the population must be recovered as priorities,and that the first capture fish have body length of 130.2 mm and body weight of 108.2 g.