MOLECULAR CHARACTERIZATION OF THE FIRST REPORTED NEOPLAGIOGLYPHE MEGASTOMUS (DIGENEA, OMPHALOMETRIDAE) IN POLAND.

The diversity and taxonomy of metacercariae infecting freshwater amphipods of Poland are predominantly poorly known. During parasitological surveys of Gammarus pulex (Crustacea: Amphipoda) in the Pomeranian region of Poland in 2020 and 2021, some specimens of crustaceans were found to harbour metacercariae. Out of seven observed localities, metacercariae were found in the stream close to Krępa Słupska and the Lupawa River close to Smoldzino. They were morphologically studied and sequenced using universal eukaryotic primers that amplify V4-V5 regions of 18S rRNA. The BLAST analysis and phylogenetic reconstructions aid to define the affiliation of the revealed metacercariae within the Omphalometridae Looss, 1899. The further differential analysis based on morphologic information led to the conclusion that the metacercarial form studied herein represents Neoplagioglyphe megastomus (Baer, 1943). The degree of morphometric variations of taxonomic important features in populations from different geographic regions was followed up. The reported here form was characterized by a larger body size that was affected by the processing methods used in the present and previous studies. To our knowledge, this is the first report of Neoplagioglyphe megastomus in Poland and is the first molecular characterization of the worm. [ABSTRACT FROM AUTHOR]