Abstract:

Aims: Our objective is to provide a better understanding on the background and community structure of fish diversity in the main inland water bodies of Shanghai.

Methods: We used specimens from 13 rivers and one reservoir in Shanghai to investigate the species resources and community structure of fish in the main inland water bodies of Shanghai. These specimens were examined qualitatively and quantitatively from July to August in summer and then from October to November in autumn in 2023.

Results: A total of 20,160 specimens belonging to 16 orders, 24 families, 57 genera, and 71 species were collected and identified. Cypriniformes, Gobiiformes, and Siluriformes accounted for 57.74%, 9.86%, and 5.63% of the total species, respectively. There were 57 species of freshwater fish, 11 species of estuarine fish, 3 species of migratory fish, and 5 exotic or artificial species. The high taxonomic composition of series Percomorpha and the rich ecological types of estuarine fish represented the characteristics of fish composition in estuarine tidal river networks in eastern China. There was an average of 35.9 species of fish in the 14 water bodies. The Punan Canal and Pudong Canal had the largest number with 47 species each, and Dishui Lake had the smallest number with 24 species. There were 15 dominant species and 14 common species with the average being 5 dominant species and 10 common species in each water body. Carassius auratus, Acheilognathus macropterus, Culter dabryi, and Chanodichthys erythropterus were the dominant species in the 14 water bodies. The Margalef richness index (D), Shannon diversity index (H'), Pielou evenness index (J'), and Simpson dominance index (C) showed fish diversity is higher in the 13 rivers such as Yuanxie River and lowest in Dishui Lake. The Cody index (β_c) of each water body ranged from 4.0-15.5 with an average of 9.9. A large species diversity was shown by the Routledge index (β_R) ranging from 12.44 to 28.76 with an average of 19.8. The ABC curve showed W was negative in most water bodies, and the abundance dominance curve was mostly above the biomass curve, showing the characteristics of community structure dominated by small and medium-sized individual fish. The fish communities in 14 water bodies were divided into 4 groups by cluster analysis. The similarities within the groups were approximately 74%, with the exception of the first group, and the differences between the groups were 31.42%-49.65%. The highest contribution of differences was Carassius auratus, Pseudorasbora parva, and Chanodichthys mongolicus.

Conclusion: Our results suggest the differences of fish community structure of main inland water bodies in Shanghai may be caused by natural conditions, regional location, release activities of the water bodies, and the land use forms where the water bodies are located. The water of the metropolis with dense buildings can also maintain a high diversity of fish species under the premise of protecting the water environment and fish habitat.

Key words: inland water body of Shanghai, species diversity of fish, fish community structure, background survey