[Otolith carbon and oxygen stable isotopes in laboratory-reared Schizothorax kozlovi]

In order to investigate the role of otolith carbon (δ¹³C) and oxygen (δ¹⁸O) stable isotopes in identification of freshwater fish stocks, otolith δ¹³C and δ¹⁸O of cultured Schizothorax kozlovi at different ages were measured by stable isotope mass spectrometer. The relationships between otolith δ¹³C / δ¹⁸O and environment were discussed. The results showed that δ¹³C and δ¹⁸O values of S. kozlovi at age 1⁺ were not significantly correlated with otolith mass, but both were significantly different between lapillus and asteriscus. The average lapillus δ¹³C and δ¹⁸O values of S. kozlovi at different ages were (-9.58±0.06)‰ and (-8.33±0.17)‰, respectively. There was no significant difference of lapillus δ¹³C and δ¹⁸O between the sexes, but with significant difference among diffe-rent ages. The correlation of δ¹³C with δ¹⁸O was an effective method in identification of different culture stocks of S. kozlovi, which indicated the isotopic signatures of otolith could be used as a method to identify freshwater fish stocks.