Haplotypes diversity of the COI gene of the pink salmon Oncorhynchus gorbuscha (Walbaum, 1792) in the Pechora river basin

Pink salmon Oncorhynchus gorbuscha (Walbaum, 1792) is an anadromous epipelagic species that forms the basis of the Far East fishing industry. The result of the work on its acclimatization carried out in the second half of the XX century was the rapid expansion of the area, including the rivers of the European northeast of Russia. The findings of this species in the Pechora river basin, which is the largest river system in the area of distribution, allowed us to carry out a general morphological description of the pink salmon. The obtained values of the meristic characteristics of the studied individuals indicate that they are close to the typical form of the pink salmon species. It is noted that the number of this species in the Pechora River is extremely unstable. The analysis of the nucleotide sequences of the cytochrome oxidase subunit 1 gene (n = 71), carried out on the basis of our own data and information from the GenBank database, revealed 15 haplotypes. The average number of nucleotide differences per site (nucleotide diversity - Pi) was 0.00303 ± 0.000024. The transitions/transversions ratio corresponded to the value of 2.4. The haplotype diversity value (Hd) is 0.823. In 11 tissue samples of pink salmon caught in the watercourses of the European northeast of Russia, 7 haplotypes of the COI gene were found, which is a fairly high ratio. An increase in the sample size will lead to the identification of even greater diversity for the studied gene in the acquired part of the range of the studied species. It is suggested that the main genetic effects of the «bottleneck» and «founder», characteristic of the populating by this species of a new territory, may not be observed. The main reason is assumed to be a fairly large number of individuals from different years of generations used in the process of introduction of pink salmon.