Host-specifity of monogeneans ectoparasites on fish skin and gills assessed by a metabarcoding approach

Monogeneans are highly diverse fish ectoparasites with a direct life cycle widely distributed and are known to generally display a strict host specificity. However, monogeneans have also been observed to colonize fish species not in their natural host range under experimental conditions. The aim of this study is therefore to investigate how monogenean host-specificity establishes during the infection in nature using a new molecular approach. We developed a specific metabarcoding protocol based on restriction enzymes and specific primers and applied it on the Sparidae-Lamellodiscus host parasite system, to assess parasite diversity on skin and gills of several sparid host species. Here, we provided i) the metadata file, 2) the ASV table with sequences assigned with the SILVA 138 database, 3) the ASV table rarefied, 4) the ASV table rarefied with assignments of all monogenean sequences by BLAST and 5) the final ASV table which summarizes all Lamellodiscus sequences identified in each sample.
We identified a high diversity of both expected and unexpected (never observed on this host species) Lamellodiscus species on each host species and on skin and gills. These results suggest that the establishment of the observed host specificity in monogeneans relies on multiple levels of regulation and is more complex than initially described.