Parasitic flatworms infecting thorny skate, Amblyraja radiata: Infection by the monogeneans Acanthocotyle verrilli and Rajonchocotyle emarginata in Svalbard

Parasite diversity above the Arctic circle remains understudied even for commercially valuable host taxa. Thorny skate, Amblyraja radiata, is a common bycatch species with growing commercial value. Its natural range covers both sides of North Atlantic including zone. Svalbard Norwegian archipelago located on northwest corner Barents Shelf which sustains spectacular diversity. So far, several monogenean have been reported infecting thorny skate across Ocean. In present study, we intend to fill in knowledge gap parasites northern part its and thus indirectly assess connectivity between populations off coast from previously studied locations. 46 individuals were recovered 11 specimens skate. Following morphological molecular assessment, two monogeneans, Acanthocotyle verrilli Rajonchocotyle emarginata, identified. The results serve as northernmost record parasite genera first Svalbard. Detailed morphometric evaluation revealed relatively high level variation A. compared congeners. Phylogenetic reconstruction placed well-supported clade imo. Our study also suggests diagnostic significance sclerotised structures identification Rajonchocotyle. Even though occurrence directly transmitted supports suggested long-distance migration future studies employing highly variable genetic markers are needed ongoing historical patterns.