关键词：
切尾拟鲿;年龄结构;生长特性;资源利用;乌江
摘 要：
为研究乌江流域切尾拟鲿Pseudobagrus truncatus的年龄结构、生长特性和资源利用现状,补充该鱼的乌江种群数据,于2016年6月-2017年8月对采集自乌江中游支流石阡河(佛顶山国家级自然保护区山麓)的253尾切尾拟鲿进行了相关研究,对比了其脊椎骨、主鳃盖骨、微耳石和星耳石的年轮清晰度和规律性,并选择脊椎骨作为年龄鉴定材料.结果表明:切尾拟鲿年龄结构包括1~5龄,其中1龄占80.2%;体质量与体长的幂函数方程为W=7.4*10-5L2.652(R2=0.941);选择Von Bertalanffy生长方程作为体长(L)、体质量(W)与年龄(t)的拟合关系式,即Lt=469.757[1-e-0.127(t-0.228)],Wt=901.653[1-e-0.127(t-0.228)]2.652;体长生长速度和加速度无拐点,而体质量均有,拐点年龄为7.91 a,对应体长为292.62 mm,体质量为256.96 g;用Pauly相关公式探讨了切尾拟鲿的资源利用现状,年开发率为0.846,年总死亡系数为2.040,年自然死亡系数为0.315;假设开发率不变,当起捕体长为241 mm时,相对单位补充渔获量(0.022 62)和生物量(0.026 85)达到最大,对应年龄为5.44 a,体质量为153.6 g.研究表明,当前切尾拟鲿处于严重小型化和低龄化状态,为切实保护该鱼资源建议配合保护区做好禁渔措施.
作 者：
LI Zhong-li;MEI Jie;LEI Hong-mei;YANG Tian-you;ZHANG Lei;College of Agroforestry Engineering and Planning, Tongren University;The Administration Bureau of the Fodingshan National Nature Reserve;
关键词：
Pseudobagrus truncatus;;age structure;;growth characteristics;;resources utilization;;Wujiang River
摘 要：
Growth features were estimated by Von Bertalanffy growth model,and clarity and regularity of annual rings on vertebra, opercular, lapillus and asteriscus were investigated for aging identification by vertebrae in 253 specimen of cuttail bullhead Pseudobagrus truncates collected in the tributary around the foothill of Foding Mountain National Nature Reserve of Middle Reaches of Wujiang River from June 2016 to August 2017 in order to evaluate the current situation of the cuttail bullhead stock utilization by classical Pauly's empirical equation. The cuttail bullhead had age structure ranging from 1 to 5 year-old and dominated by 1, accounting for 80.2%. The relationship between body weight(W) and body length(L) was expressed as an exponential equation as W=7.4×10~(-5)L~(2.652)(R~2=0.941). The fitting relation was shown to be L_t=469.757[1-e~(-0.127(t-0.228))], W_t =901.653[1-e~(-0.127(t-0.228))]~(2.652) in relationship between body weight(W) and age. There was no inflexion point in growth rate and growth acceleration of body length, and compared with body length conversely, with inflexion point of 7.91 years old, corresponding body length of 292.62 mm and body weight of 256.96 g. Pauly correlation formula revealed that the cuttail bullhead had annual exploitation rate of 0.846, total annual mortality coefficient of 2.040 and annual natural mortality coefficient of 0.315. The maximal relative yield per unit recruit(0.022 62) and relative biomass per unit recruit(0.026 85) were supposed to be obtained under the conditions of constant exploitation rate, and the first captured fish with body length of 241 mm, age of 5.44-year-old and body weight of 153.6 g. It is suggested that it be to take closed fishing measures to protect the wild populations of cuttail bullhead effectively due to the serious becoming lower in age and miniaturization of cuttail bullhead population.
