Biodiv Sci ›› 2024, Vol. 32 ›› Issue (11): 24143.  DOI: 10.17520/biods.2024143  cstr: 32101.14.biods.2024143

• Original Papers: Animal Diversity • Previous Articles     Next Articles

The status and distribution pattern of fish diversity in the Yarlung Tsangpo River

Dekui He *, Jinnan Chen , Liuyong Ding , Yiyang Xu, Junhao Huang, Xiaoyun Sui   

  1. Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China

  • Received:2024-04-12 Revised:2024-06-26 Online:2024-11-20 Published:2024-08-11
  • Contact: Dekui He

Abstract:


Aims: The Yarlung Tsangpo River, one of the ten longest rivers in China, spans two major zoogeographic regions of the world: the Palearctic and the Oriental realms. While previous papers have focused on small portions of the river, a basin-wide-scale study to catalog its fish composition, diversity patterns, and species fluctuation is lacking. This study synthesizes empirical data from field studies over the past two years on fish diversity in the Yarlung Tsangpo River. This includes a compiled list of fish diversity in the Yarlung Tsangpo River Basin in China, analysis of the status of the fish diversity, and the main threats to its diversity. The findings provide a solid scientific foundation for management and conservation of fish diversity in the Yarlung Tsangpo River Basin.  

Methods: Sixty-two locations were sampled in this study, including locations along the Yarlung Tsangpo River’s main stream and tributaries. These locations were selected according to their geomorphological characteristics, as well as the accessibility of each location for sampling. There are 24 sampling locations from the main stream, 38 in the tributaries (including the mouth of a tributary, three reservoirs, and two lakes). Of them, there are two in the upper reaches, 36 in the middle reaches, and 24 in the lower reaches. The samples from these studies were collected between 2004 and 2023. Methods for collecting fish included gillnets, shrimp coops, and battery-powered backpack electrofisher. After compiling the data from all of the sites, the degree of endemicity was calculated using the corrected weighted endemism index.

Results: There are 155 native species in 10 orders, 25 families, and 70 genera in the Yarlung Tsangpo River Basin. Out of all of the detected species, 29 species and one genus are endemic to the river. Four species were on China’s Key Protected Species List (Grade II); and 27 species were on the International Union for Conservation of Nature Red List of Threatened Species and China’s Biodiversity Red List (endangered, vulnerable, or near threatened). The fish species richness is the highest in the Yarlung Tsangpo River at the middle and lower reaches of the river, while the lowest species richness is found in the Great Canyon sections. Fish fauna of the river is dominated by Central and High Asian, and South Asian fishes. The Jiaresa-Bangxing section of the Yarlung Tsangpo River Grand Canyon is predicted to be the boundary between the two major zoogeographical regions of freshwater fish. By the end of 2023, 30 species of non-native fish species from eight orders, 16 families, and 24 genera had been recorded in the natural water bodies of the Yarlung Tsangpo River Basin. Of these non-native fish species, three species were introduced to different regions within the Yarlung Tsangpo River Basin. In recent years, there has been a rapid increase in the introduction of both native fishes and non-native cold-adapted fishes through the plateau’s drainage systems.

Conclusion: Through cataloging the fish diversity in the Yarlung Tsangpo River Basin, we found that invasion of non-native fishes is the main threat to fish diversity. In the future, we should focus on fish surveys of lakes and tributaries in the lower reaches of the river, strengthen the resources for data integration, and establish a basin-level data management platform. Further, taxonomic research should be strengthened through international cooperation. Additionally, long-term monitoring of fish resources should be implemented as soon as possible to monitor fish diversity and promote conservation in the Yarlung Tsangpo River.


Key words: Non-native fishes, Dam, Taxonomy, Biodiversity, Fauna, Threat facts