西藏雅鲁藏布江双须叶须鱼的年龄结构与生长特征 [中文引用][英文引用]

根据2008-2009年、2012年以及2013年采自雅鲁藏布江水系的956尾样本对双须叶须鱼(<i>Ptychobarbus </i><i>dipogon</i>)的年龄结构和生长特征进行研究.雌性渔获物体长范围为146~569 mm, 雄性渔获物体长范围为167~506 mm, 性别未辨渔获物体长范围为78~297 mm; 耳石上的年轮形成于每年的3-6月份; 估算的雌性群体年龄范围为3~24龄, 雄性群体年龄范围为3~13龄, 性别未辨群体年龄范围为2~6龄.体长(<i>L</i>_s)-体重(<i>W</i>)方程分别为: <i>W</i>=2.494&#215; 10^-5<i>L</i>_s^2.877(雌性), <i>W</i>=2.790&#215;10^-5<i>L</i>_s^2.856(雄性); 拟合出来的von Bertalanffy生长方程为: <i>L_t</i>=606.9[1-e^{-0.114(<i>t</i>+0.163)}], <i>W_t</i>=2538.4[1-e^{-0.114(<i>t</i>+0.163)}]^2.88(雌鱼); <i>L_t</i>=496.3[1-e^{-0.162(<i>t</i>-0.018)}], <i>W_t</i>=1391.1[1-e^{-0.162(<i>t</i>-0.018)}]^2.86(雄鱼).估算的雌鱼和雄鱼的拐点年龄分别为9.1龄和6.5龄, 对应的体长和体重分别为396.0 mm、743.6 g和322.5 mm、406.3 g.研究表明, 双须叶须鱼种群结构趋向低龄化, 可能受全球气候变化、生物入侵和过度捕捞等因素的影响.针对这些影响因素, 本研究提出了相应的渔业管理措施.

<i>P</i><i>tychobarbus dipogon </i>is one of the most important endemic fish species in the upper and middle reaches of the Yarlung Tsangpo River. However, <i>P. dipogon </i>populations have declined sharply in recent years and their biology is poorly understood. To better understand the biology of <i>P. dipogon </i>and their relationship with management, we describe the relationships between standard length and body weight and age, verify annual growth of lapilli otolith annuli, and estimate <i>P. dipogon</i> growth. The age structure and growth characteristics of <i>P. dipogon</i> were investigated by examining 956 specimens collected in the Yarlung Tsangpo River during 2008-2009 and 2012-2013. Standard lengths were 146-569 mm in females, 167-506 mm in males, and 78-297 mm in some undetermined specimens. Otolith annuli formed from March-June each year. Estimated ages were 3-24 years in females, 3-13 years in males, and 2-6 years in undetermined specimens, respectively. The standard length-body weight relationships were described by <i>W</i>= 2.494 &#215; 10^-5<i>L</i>_s^2.877for females and <i>W</i>= 2.790&#215;10^-5<i>L</i>_s^2.856 for males. The von Bertalanffy growth equations were: <i>L_t</i>= 606.9[1-e^-^{0.114(<i>t</i>+0.163)}] and <i>W_t</i>=2538.4[1-e^-^{0.114(<i>t</i>+0.163)}]^2.88 for females and <i>L_t</i>=496.3[1-e^-^{0.162(<i>t</i>}^-^0.018)] and <i>W_t</i>=1391.1[1-e^-^{0.162(<i>t</i>}^-^0.018)]²^.86 for males. The growth inflexion points were 9.1 years for females and 6.5 years for males, and the corresponding standard lengths and body weights were 396.0 mm and 743.6 g for females and 322.5 mm and 406.3 g for males, respectively. Our results show that the <i>P. dipogon</i> population tended to be younger. Climate changes, biological invasion, and over-exploitation could be the main factors threatening <i>P. dipogon</i> stocks. The sound management policies proposed in this study should be implemented to conserve <i>P. dipogon</i> populations.