Abstract:
Aims: The study aims to investigate the fish composition and diversity patterns in the source region of the Yangtze River, one of the most critical water conservation zones worldwide.
Methods: Field surveys were conducted in the headwaters of the Yangtze River, including the Tuotuo, Chumaer, Dam Qu, Tongtian, and Dadu rivers in Qinghai Province from 2021 to 2022. Data on the presence and abundance of fish, as well as environmental factors, were collected during the surveys.
Results: A total of 26 species (and subspecies) were recorded in the field surveys, belonging to 12 genera, 3 families, and 2 orders. Analysis of the index of relative importance (IRI) revealed that Schizopygopsis malacanthus and Herzensteinia microcephalus were the dominant species. Seven species are newly recorded, including four native species and three non-native species. Alpha diversity indices showed higher species diversity in the Tongtian and Dadu rivers compared to other tributaries, while the Yalong River exhibited a more uneven species distribution. Similarity coefficient analysis and principal coordinates analysis (PCoA) indicated significant differences in species composition among tributaries, highlighting the influence of geographic isolation and ecological adaptation on fish diversity. Canonical correspondence analysis (CCA) revealed notable differences in fish community structures across different river systems, with water temperature and altitude identified as key determinant factors. Spatial autocorrelation analysis indicated that the fish distribution patterns were random, with a slight tendency towards clustering. The Getis-Ord Gi* analysis identified two hotspots in the Dadu and the Tongtian rivers.
Conclusion: This study provides updated information on the fish composition in headwaters of the Yangtze River and enhances our understanding of spatial variations in fish diversity in the region. These findings lay the foundation for scientific management and conservation of native fish in the source region of the Yangtze River.
Key words: Qinghai Province, the source region of the Yangtze River, fish diversity, fish species composition, spatial distribution
Fig. 3 Principal coordinates analysis (PCoA) of fish communities in each water system of the Yangtze River source region. Points in different colors represent fish communities from different water systems. The distribution of points illustrates the community structure differences among water systems.
The link below will guide you to the reading:
https://www.biodiversity-science.net/EN/10.17520/biods.2024494