NOBANIS - Invasive Alien Species Fact Sheet Gyrodactylus salaris

Species identification Gyrodactylids are ubiquitous monogenean ectoparasites on the skin and gills of teleost fish both in marine and freshwater ecosystems. The most recent species compilation lists some 400 gyrodactylid species. Gyrodactylus salaris is a species of this genus found on fins and skin of Atlantic and Baltic salmon in its freshwater phase (Figure 1). The small (0.5 1 mm) parasite was described by Malmberg (1957) from salmon parr in a hatchery situated at the river Indalsälven in Sweden. Since then, there have been a growing number of observations of G. salaris from several countries both on wild fish and on fish in hatcheries and freshwater fish farms.