西藏浪错兰格湖裸鲤的年龄与生长

2017年7月—2018年5月,于西藏自治区昂仁县浪错采集268尾兰格湖裸鲤Gymnocypris chui开展种群年龄结构和生长特征研究。结果显示:雌、雄鱼体长与体质量的关系式分别为W♀=2.03×10-2L2.822(n=134,R2=0.969)、W♂=2.52×10-2L2.738(n=105,R2=0.966)。通过观察微耳石,发现样本由1~23龄组成;采用VonBertalanffy生长方程拟合雌、雄鱼体长、体质量生长方程:Lt♀=34.2391-e-0.136(t+0.11)]、Wt♀=434.421-e-0.136(t+0.11)]2.822;Lt♂=32.2011-e-0.136(t+0.287)]、Wt♂=338.81-e-0.136(t+0.287)]2.738;拐点年龄分别为7.52龄和7.12龄,对应体长分别为22.12cm和20.45cm,体质量分别为126.59g和97.71g。初步研究表明,兰格湖裸鲤生长慢、体型小,种群被破坏后不易恢复,亟待开展资源评估及保护工作。

Age and Growth of Gymnocypris chui in the Lang Tso,Tibet

In order to study the age and growth of Gymnocypris chui,268 individual fish were collected from July 2017 and May 2018 in the Lang Tso,Ngamring county,Tibet Autonomous Region.Sample ages ranged from 1 to 23 years old by otolith.The relationship between standard body length(L)and total body mass(W)of females and males could be expressed as W♀=2.03×10-2 L 2.822(n=134,R 2=0.969)and W♂=2.52×10-2 L 2.738(n=105,R 2=0.966),respectively.The Von Bertalanffy growth equations for standard body length and total body mass of females and males could be expressed as L t♀=34.2391-e-0.136(t+0.11)],W t♀=434.421-e-0.136(t+0.11)]2.822,L t♂=32.2011-e-0.136(t+0.287)]and W t♂=338.81-e-0.136(t+0.287)]2.738.The growth inflection point of age for females was 7.52 years,with the standard body length of 22.12 cm and the total body mass of 126.59 g.The growth inflection point of age for males was 7.12 years,with the standard body length of 20.45 cm and the total body mass of 97.71 g.These results suggested that G.chui has relative slow growth rate and small size,and the destroyed population of which might be difficult to recover from low density.Therefore,the assessment and protection works on G.chui resources are urgently needed in the Lang Tso.