Sample collection and processing
All fish samples were collected by nets and cages with the help of local
fisherman during October to December 2019. Each fish sample was
identified to the species level according to Chen (1998), Yue (2000),
Chu (1999), and Fishbase (Froese & Pauly, 2018).
A total of 2157 individuals were collected, representing 57 fish species
belonging to 13 families and 10 orders (Supplement Appendix 1). After
preserving an appropriate amount of muscle tissue in 95% alcohol for
molecular analysis, the whole body was fixed in 10% formalin and
deposited in the Institute of Hydrobiology, Chinese Academy of Sciences.
For stable isotope analysis, white dorsal muscle was collected and
rinsed with distilled water. The cleaned muscle was dried to a constant
weight in an oven at 60 ℃ for at least 48 h and homogenized to powder by
an automatic grinder, which was finally stored in clean centrifuged
tubes until analysis.