Understanding the feeding ecology of Cynoglossus joyneri in Haizhou Bay based on stable isotope analysis.

We analyzed the feeding ecology of by carbon and nitrogen stable isotope analysis based on the samples collected from the bottom trawl surveys during spring and autumn of 2018 in Haizhou Bay, China. The results showed that the δC and δN values of ranged from -20.75‰ to -15.91‰ and from 5.98‰ to 12.02‰, respectively. The mean values of the δC and δN were (-17.79±1.00)‰ and (9.37±1.33)‰, respectively. There was a significantly negative correlation between the δC values and standard length and a positive correlation between the δN values and standard length. The mean trophic level of was (3.43±0.97). There was a significantly positive correlation between the trophic level and standard length. The dominant prey groups of were fish, crabs, shrimps, mollusca, polychaeta, plankton and particle organic matter (POM). The trophic contribution of shrimps was the highest among these prey groups. The trophic contribution of fish, crabs and shrimps was higher in autumn than those in spring. This study would help to understand the role of in the material cycling and energy flow in Haizhou Bay ecosystem, and provide scientific basis for the protection and rational utilization of this species.