Abstract:Different salmons are from relative species and very similar in appearance. The aim of this study was to establish a species traceability method for Atlantic salmon, chum salmon and rainbow trout. A total of 912 proteins were identified at 95% confidence level based on mass spectrometry shotgun proteomics. Potential peptide biomarkers derived from different salmon unique proteins were assessed by detection specificity as well as species uniqueness, and the qualified ones were further validated by multiple reaction monitoring (MRM) based peptidomics, resulting in 10 species-specific peptides for Atlantic salmon, 2 species-specific peptides for chum salmon and 3 species-specific peptides for rainbow trout. The results demonstrated that the proposed approach is simple, accurate, reliable, specific and robust, and can be effectively used for the identification and analysis of commercial salmon products in routine analytical laboratories. Keywords Salmo salar; Oncorhynchus keta; Oncorhynchus mykiss; marker peptides; mass spectra; proteomics; species identification