Composition and structural characteristics of fish communities in the Baihe River and the Heihe River,tributaries of the upper reaches of the Yellow River
The Baihe River and the Heihe River,which are both tributaries of the upper Yellow River in Sichuan Province,China,exhibit unique environmental and climatic conditions that support a diverse fish population. To investigate the species composition,community structure,and diversity of fish species in these rivers,this study incorporated historical data and field surveys that were conducted during the winter of 2022 (November),and in the spring (April),summer (July),and autumn (September) of 2023. A total of 2936 individuals from 11 species,spanning 8 genera,2 families,and 1 order,were collected. Among these,the following four were endemic to the upper reaches of the Yellow River:Platypharodon extremus,Gymnocypris eckloni,Schizopygopsis pylzovi,and Chuanchia labiosa. Additionally,four species classified as second-class protected fish in China,namely,Triplophysa siluroides,Gymnodiptychus pachycheilus,P. extremus,and C. labiosa,and one provincial protected species,Triplophysa papptnhtimi,were detected. Two exotic species,Cyprinus carpio and Carassius auratus,represented 36.36％,36.36％,9.09％,and 18.18％ of the total species identified in November 2022,April 2023,July 2023,and September 2023,respectively. Among the collected species,seven belonged to the Cyprinidae family and four to the Cobitidae family,accounting for 63.64％ and 36.36％ of the total number of species,respectively. The index of relative importance value indicated that the dominant species in the Baihe River were G. eckloni and Triplophysa scleroptera,while the dominant species in the Heihe River were G. eckloni and G. pachycheilus. The Shannon-Wiener diversity index value ranged from 1.764 to 2.364,the Margalef richness index value ranged from 1.364 to 1.798,and the Pielou evenness index value ranged from 0.7854 to 0.8747. Notably,the fish biodiversity index peaked in autumn. The abundance/biomass comparison curve indicated a stable fish community structure in both the Baihe River and Heihe River,dominated by large individual species with minimal external disturbances. Cluster and non-metric multidimensional scaling analysis revealed that the fish communities in the Baihe River and Heihe River could be classified into three distinct groups. Furthermore,when compared with historical data,there was a notable decrease in fish diversity in the Baihe River and Heihe River,accounting for 72.73％ and 66.67％ of the historical total number of species,respectively. The upper reaches of the Yellow River exhibited a high proportion of unique and protected fish species,characteristic of the typical Qinghai-Tibet (Central Asian) Plateau fish fauna. This study provides valuable data on fish community dynamics in the main tributaries of the Yellow River in Sichuan and offers recommendations for the protection of unique fish species in the upper reaches of the Yellow River.
万方数据
维普
