Developmental stability in vaccinated Atlantic salmon (Salmo salar L.): Deformities and fluctuating asymmetry of bone structures

Vaccination has recently become a widely considered factor influencing the development of farmed fishes. In the present study, developmental stability of bone structures of vaccinated and nonvaccinated Atlantic salmon is investigated using two parameters, the frequency of deformities and fluctuating asymmetry (FA, nondirectional deviations from perfect bilateral symmetry). Vaccinated salmon show a higher frequency of bone deformities, suggesting a decrease in developmental stability caused by vaccination. On the contrary, the level of FA does not differ in vaccinated and nonvaccinated fishes. The results are discussed from the point of view of influence of mechanical load on the development of bone structures of the Atlantic salmon.