In this study, the population variability in chromosome numbers of rainbow trout (Oncorhynchus mykiss) cultured in 10 farms in the Northeast Black Sea Region of Turkey is examined. From the analysis of 468 anterior kidney tissue cells from 118 specimens, 7 distinct diploid numbers, namely 2n=58, 2n=59, 2n=60, 2n=61, 2n=62, 2n=63 and 2n=64, were found. The most frequent karyotypes with proportions of 25.2% and 24.8% were 2n=60 and 2n=62 respectively. Extensive Robertsonian polymorphisms were determined. According to the polymorphism results, it was concluded that the strains in these farms probably originated from European culture populations and the need to repopulate these stocks with non-heterogeneous stocks was suggested.

In this study, the population variability in chromosome numbers of rainbow trout (Oncorhynchus mykiss) cultured in 10 farms in the Northeast Black Sea Region of Turkey is examined. From the analysis of 468 anterior kidney tissue cells from 118 specimens, 7 distinct diploid numbers, namely 2n=58, 2n=59, 2n=60, 2n=61, 2n=62, 2n=63 and 2n=64, were found. The most frequent karyotypes with proportions of 25.2% and 24.8% were 2n=60 and 2n=62 respectively. Extensive Robertsonian polymorphisms were determined. According to the polymorphism results, it was concluded that the strains in these farms probably originated from European culture populations and the need to repopulate these stocks with non-heterogeneous stocks was suggested.