Morphological diversity and differentiation of Asian populations of pink salmon Oncorhynchus gorbuscha (Walbaum) of even generations

Abstract

A morphological study of three Asian populations of pink salmon of the Ola, Bolshaya and Zhupanov rivers of adjacent even generations was carried out. For a quantitative description of the external appearance of pink salmon, a scheme of 17 measurements proposed by M.K. Glubokovsky [2] was used. Ola’s pink salmon is, on average, smaller than pink salmon from Kamchatka populations. Pink salmon from Kamchatka populations have a higher body size (measurements B14–17) than those of the Olsky ones. The highest-bodied pink salmon of the Bolshaya and Zhupanova rivers differ among themselves in 16 measurements of female, males — in 12 measurements. The high degree of morphological differences of pink salmon from three rivers allows us to correctly use the term populations for spawning populations in these rivers. Factorial analysis of the values of measurements of individuals revealed a significant influence of the first factor, its value is determined by the variability of traits in individuals in each populations. The impact of all other factors is not significant. Obviously, the first factor can be attributed to the ecological conditions during the freshwater period of the life of juveniles in the river. The second and third factors indicate inter-sampling differences less than those of the first factor. The degree of influence of external factors is different for females and males in each population. Interannual fluctuations in the morphological measurements of samples from different years determine the values of other factors.