秦岭细鳞鲑的年龄与生长

 2009—2012年于陕西省陇县秦岭细鳞鲑(Brachymystax lenok tsinlingensis)国家级自然保护区内采集秦岭细鳞鲑样本397尾。以鳞片为年龄鉴定材料, 显微镜下观察发现, 秦岭细鳞鲑鳞片上的年轮特征主要表现为普通切割形; 研究样本的年龄共分为5个年龄组, 其中以1～3龄为主, 约占85.64%; 体长(L, mm)和鳞径(R, mm)具有显著的相关性(L= -5.83R² + 208.06R + 34.99, r²=0.88); Von Bertalanffy生长方程分别为: L_t=729.381-e^-0.08(t+0.5)], W_t=        6 288.74·1-e^-0.08(t+0.5)]^{2.968 1}, 雌雄个体的生长速率无显著差异; 生长系数为0.08, 拐点年龄为13.10 龄, 对应的的体长和体质量分别为483.66 mm和1 857.86 g。结论认为, 秦岭细鳞属生长缓慢型鱼类, 在所调查的保护区中秦岭细鳞鲑显现出个体小型化趋势。在制定资源保护策略时, 应考虑采取人工增殖放流措施来扩大自然种群数量, 增强种群的自然调节能力, 恢复种群数量。本研究旨在了解秦岭细鳞鲑的生长规律, 为秦岭细鳞鲑的资源保护与合理利用提供理论指导。

Age and growth of Brachymystax lenok tsinlingensis

We evaluated the age structure and growth characteristics of Brachymystax lenok tsinlingensis based on scale analysis. We collected 397 B. lenok tsinlingensis specimens from Long-xian, Shanxi, between 2009 and 2012. The scale annuli were characterized as the commonly-cutting shape. We observed 5 age groups, with 1-3 year-old individuals accounting for 85.64% of the total samples. There was no significant difference in body length (L) and body weight (W) between females and males and the Von Bertalanffy growth model was L_t=729.381-e^-0.08(t+0.5)] and W_t=6 288.741-e^-0.08(t+0.5)]^{2.968 1}. The coefficient of growth (k) was 0.08. The body weight growth inflexion point was at 13.10 years old, with a corresponding body length of 483.66 mm and body weight of 1 857.86 g. The results show that B. lenok tsinlingensis is a species of slow growing fish and it characterizes isometric growth and individual miniaturization in the natural reserve. We should take artificial propagation and artificial releasing to enlarge and revive its populations. The study is intended to realize its growth rhythm and take reasonable actions to protect and vitalize B. lenok tsinlingensis.