雅鲁藏布江水系尖裸鲤的分布和食性差异研究

Distribution and Feeding Habit Difference of Oxygymnocypris stewarti in the Yarlung Zangbo River System

为了保护与合理利用尖裸鲤(Oxygymnocypris stewarti)资源,利用2015~2020年对西藏自治区重点水域渔业资源调查的资料,研究了尖裸鲤的资源分布和食性差异。研究结果表明,在西藏自治区,尖裸鲤仅在雅鲁藏布江水系分布,尖裸鲤主要分布在雅鲁藏布江上游和中游(仲巴县至仁布县江段)及其支流,零星分布在朗县江段和派镇江段,在高原湖泊巴松措中也分布着尖裸鲤,分布的海拔范围为2900~4700 m;在雅鲁藏布江中上游仲巴县江段、萨嘎县江段、拉孜县江段和日喀则市江段分布的尖裸鲤都以鱼类为主要食物,随着海拔的降低,各江段尖裸鲤的食物组成无显著差异,但是尖裸鲤对食物的摄食强度存在差异,仲巴县江段和萨嘎县江段尖裸鲤的食物平均饱满指数值显著偏大,而拉孜县江段和日喀则市江段的尖裸鲤的食物平均饱满指数值较小。近年来,尖裸鲤资源呈现衰减趋势,因此,应该在雅鲁藏布江上游江段和中游的仲巴县江段建立尖裸鲤自然保护区,加强对尖裸鲤的保护和资源恢复力度,加强尖裸鲤的增殖放流和相关基础研究工作。

In order to protect and rationally utilize the resources of Oxygymnocypris stewarti, and using the data of fishery resources survey in key waters of Tibet Autonomous Region from 2015 to 2020 were used, and the resource distribution and differences of feeding habits of naked carp were studied. The results showed that Oxygymnocypris stewarti was only distributed in Yarlung Zangbo River system in Tibet of China, and Oxygymnocypris stewarti was mainly distributed in the upper and middle reaches(from Zhongba reach to Renbu reach) and tributaries of Yarlung Zangbo River, and scattered in Langxian reach and Paizhen reach, and were also distributed in the Basum Lake, and the elevation of distribution is 2900 m to 4700 m.Oxygymnocypris stewarti mainly feed on fish in the Zhongba, Saga, Lazi and Rikaze reaches of the Yarlung Zangbo River. There were no significant difference in the food composition among different reaches as the altitude goes down. However, there were significant spatial differences in feeding intensity, the average stomach fullness index of Oxygymnocypris stewarti in Zhongba and Saga reaches were significantly higher than the other two reaches(Lazi reach and Rikaze reach). In recent years, the resources of Oxygymnocypris stewarti showed a declining trend, so the nature reserve should be established in the upper and middle(Zhongba reach) reaches in the Yarlung Zangbo River, and to strengthen the protection and resource recovery of Oxygymnocypris stewarti, and to strengthen the proliferation and release of Oxygymnocypris stewarti and related basic research.