Effects of the Habitat and Genotype on Osteological Traits in Landlocked and Anadromous Ecological Forms of Atlantic Salmon Salmo salar Linnaeus, 1758

Studies of speciation and intraspecific differentiation in salmonid fishes are traditionally based on analysis of osteological traits. In the current study the variation of osteological traits was compared between two Atlantic salmon forms: anadromous and landlocked. Each form was represented by three samples: one from a wild population, and two from hatcheries; i.e., we studied six samples in total. In total, 45 osteological characters were analyzed. Differences between the forms were found to be genetically determined to a substantial extent. The factor origin explained 48% of the total morphological difference between the fish samples; the factor habitat, 32%; and their interaction, 14%. Phenotypic plasticity of the anadromous form was observed to be lower than that of the landlocked form. We consider that the higher phenotypic plasticity may compensate for a decrease in genetic diversity which is observed in landlocked forms of the species.

Automated summary

This study compared the variation of osteological traits between two forms of Atlantic salmon: anadromous and landlocked. It found that the differences between the forms are genetically determined to a substantial extent. The anadromous form was observed to have lower phenotypic plasticity compared to the landlocked form.