To investigate the growth, mortality, and resource utilization of Gymnocypris chui in Langcuo Lake of Tibetan Plateau, we measured body length and body weight of 389 fish based on four sampling surveys from October 2018 to November 2019. We identified the ages through lapillus. Based on frequency distribution of body length, we estimated the growth and mortality coefficients of G. chui in Langcuo Lake and the utilization status of existing population resources according to the Beverton-Holt dynamic comprehensive model. The results showed that G. chui were mainly composed of individuals aged 2 to 19 years in Langcuo Lake, with a length-body weight relationship equation of W=0.0105L3.042. The von Bertalanffy growth equation revealed that the fish had an asymptotic body length of L∞=37.28 cm, growth coefficient of k=0.160, and theoretical growth starting age of t0=-0.887 a. The total mortality coefficient Z was estimated as 0.48, based on the length-converted catch curve method. According to Pauly's empirical formula, the natural mortality coefficient M was 0.34, fishing mortality coefficient F was 0.14, and exploitation rate E was 0.29, indicating that G. chui resources in Langcuo Lake were not over-exploited. Considering the growth and mortality of G. chui in Langcuo Lake, fishing is appropriate, with a recommended fishing length of Lc=22.37 cm.
为探究西藏朗错兰格湖裸鲤的生长、死亡及资源利用状况,本研究根据2018年10月—2019年11月4次采样调查,测定了389尾样本的体长和体重,并通过微耳石进行了年龄的鉴定。基于体长频率分布数据,估算了兰格湖裸鲤种群生长、死亡系数,并根据Beverton-Holt动态综合模型对其现存种群资源利用状况进行评估。结果表明: 兰格湖裸鲤主要由2～19龄个体组成,体长与体重关系式为W=0.0105L3.042。von Bertalanffy生长方程显示,兰格湖裸鲤渐近体长L∞=37.28 cm,生长系数k=0.160,理论生长起点年龄t0=-0.887 a。根据长度转换渔获曲线法估算兰格湖裸鲤的总死亡系数Z=0.48;采用Pauly经验公式估算兰格湖裸鲤自然死亡系数M=0.34,捕捞死亡系数F=0.14,开发率E=0.29,说明兰格湖裸鲤资源未受到过度开发。综合考虑兰格湖裸鲤生长、死亡等因素,可适当对朗错兰格湖裸鲤进行捕捞,建议开捕体长Lc=22.37 cm。.
Keywords: