Identification of released population of Japanese flounder based on stable isotopes analysis

Japanese flounder ( ) is an important releasing fish in the Yellow and Bohai Seas of China. The identification of wild and releasing population is the premise to evaluate the enhancement effects. In order to study the application of stable isotope in the identification of released population, captured juveniles in the offshore releasing area of Qinhuangdao were distinguished into wild and released population using previous method (combination of morphology and molecular). Then, the contents of carbon and nitrogen stable isotope in muscle and otoliths (including the whole and the core region) were measured. The cultured population was set as control. The results showed that δ C values (wild population: -17.19‰±0.73‰; released population: -17.10‰±0.61‰; cultured population: -20.75‰±0.07‰) and δ N values (wild population: 11.81‰±0.38‰; released population: 11.62‰±0.48‰; cultured population: 8.64‰±0.60‰) of muscle and δ C value (wild popu-lation: -4.47‰±0.35‰; released population: -4.63‰±0.29‰; cultured populatio