“…In the late 1990s, the need for methodologies permitting the confident discrimination of Gyrodactylus salaris Malmberg, 1957 from its comparatively benign congeners led to the development of several molecular markers with utility for discrimination of species within the genus (Cunningham et al 1995a, b). The internal transcribed spacers (ITS), 5.8S and 18S rDNA regions have become most used in studies on taxonomy, phylogeny and cophylogeny (Huyse et al 2002, Gilmore et al 2012, Přikrylová et al 2013, García-Vásquez et al 2018, 2019, Boeger et al 2020). The study of Cunningham et al (1995a) was the first that used gyrodactylid 18S rDNA sequences to compare their relationship to other monogenean genera.…”