澜沧江西双版纳段鱼类组成和物种多样性

Abstract

根据2018-2020年澜沧江西双版纳段5次鱼类资源调查数据，结合相关文献资料，对该流域鱼类组成及物种多样性进行了分析。结果显示：澜沧江西双版纳段此次共调查到鱼类119种，隶属于11目28科79属，而历史记录鱼类共179种，隶属于12目34科106属。随着调查的不断深入，土著鱼类种数逐渐增多，但占比却逐渐下降，外来鱼类种数逐渐增多，占比也逐渐升高；本次调查到土著鱼类92种，占鱼类种数的77.31%，占比进一步下降；外来鱼类27种，占鱼类种数的22.69%，占比进一步升高。该区域鱼类优势种为云南吻孔鲃Poropuntius huangchuchieni和少鳞舟齿鱼Scaphiodonichthys acanthopterus，常见种为长臀鲃Mystacoleucus marginatus和宽额鳢Channa gachua。有《国家重点保护野生动物名录》（2021年）鱼类5种，《中国生物多样性红色名录脊椎动物卷》（2015年）受威胁鱼类8种。相对于我国其他江河，澜沧江西双版纳段有极高水平的鱼类物种多样性，其中澜沧江干流鱼类物种多样性相对于左、右岸支流较低，左岸支流鱼类多样性高于右岸，罗梭江鱼类多样性高于其他一级支流。虽然澜沧江西双版纳段鱼类物种多样性维持在较高水平，但土著鱼类占比下降趋势明显，仍面临着严重威胁，本文分析了受威胁因素，并提出了保护建议。;Based on the data from five surveys of fish resources during 2018-2020 and literature, the fish composition and species diversity in Xishuangbanna reach of Lancang River are analyzed. The results show that there are 11 orders, 28 families, 79 genera and 119 species of fish being collected, while a total of 179 valid fish species are recorded, belonging to 12 orders, 34 families and 106 genera. With the deepening of the investigation, the number of indigenous fish species is increasing, but the proportion is decreasing; while the number of exotic fish species is increasing, and the proportion is increasing. In these surveys, 92 species of indigenous fish are found, accounting for 77.31% of the total number of fish species, and the proportion decreases further. 27 species of exotic fish are collected, accounting for 22.69%, the proportion increases accordingly. The dominant species of fish are Poropuntius huangchuchieni and Scaphiodonichthys acanthopterus, and common species are Mystacoleucus marginatus and Channa gachua. Five fish species are listed on the List of Key Protected Wild Animals in China (2021) and eight species as threatened species in the Redlist of China's Biodiversity:Vertebrate (2015). Fish species diversity in Xishuangbanna reach of Lancang River is extremely high among river of China. The fish species diversity of the main stem of Lancang River is lower than that of tributaries, while that of the left bank tributary is higher than the right bank, and that of the Luosuo River is higher than that of other tributaries. Although the fish species diversity maintains a high level in Xishuangbanna reach of Lancang River, the proportion of indigenous fish is declining obviously and it is still facing serious threats. The threats are analyzed and some suggestions on conservation are proposed.