Evaluating a method for identifying Pacific salmon of the genus Oncorhynchus using microsatellite markers in industrial fish products

The goal of this study is to assess a method for identifying salmon of the genus. Oncorhynchus using microsatellite markers developed by a team led by L. A. Zhivotovsky. This method was applied to fish products intended for commercial sale. Materials and Methods: The study utilized samples of processed salmon products available at retail outlets on Sakhalin Island. To verify microsatellite analysis, the species identity of the samples was confirmed using DNA barcoding. Novelty: The studies conducted have shown that the method is effective in determining the species origin of various salmon products, including salted, smoked, dried, highly processed items (such as canned salmon) and caviar. Additionally, this method can identify the species composition of unstructured mixtures, such as minced meat and its semi-finished products. Results: we successfully identified the species of all commercially produced Pacific salmon products analyzed in this study, including highly processed items and mixed minced meat from multiple fish species. However, we encountered difficulties with mislabeled rainbow trout products. We found several cases where the fish products did not match the species indicated by the sellers. This discrepancy was most notable among the valuable Pacific salmon species: sockeye salmon, masu salmon, coho salmon, and chinook salmon. It is important to highlight that all the chinook salmon products tested were found to be rainbow trout, and the triploidy detected in these samples suggests their origin is from aquaculture. Practical significance: unlike the commonly used DNA barcoding method, microsatellite analysis can be applied to a wide range of products from Pacific salmon of the genus Oncorhynchus. This approach is particularly advantageous because it can detect samples with highly fragmented DNA as well as mixtures of DNA from different species. Therefore, microsatellite analysis shows promise for use in genetic laboratories that are analyzing fish products.