Theromyzon maculosum (Rathke, 1862) as a vector of potentially pathogenic fungi in aquatic ecosystems

The aim of the study was to check the integument and alimentary tract of Theromyzon for the occurrence of fungi. Moreover, the mycological purity of water sources from which leeches were collected was analyzed. The potential role of the duck leech Theromyzon maculosum in transmitting pathogenic fungi has not been studied until now. Mycological analyses were performed according to the procedure approved in mycological diagnostic laboratories, using classical diagnostic methods (macro- and microcultures, microscopic observations). In total, 22 species of yeasts were detected. The specimens belong to eight genera: Candida, Citeromyces, Debaryomyces, Kluyveromyces, Lodderomyces, Pichia, Saccharomyces and Saccharomycodes. Overall, 18 species of fungi were isolated from leeches Theromyzon maculosum, including seven species from the integument and 11 species from the gastrointestinal system. Among fungi isolated from body integument, fungi of the genus Candida were dominant, whereas in the gastrointestinal system, the genus Saccharomyces dominated. From the river waters, nine fungi species were isolated, and yeasts of the genera Candida and Kluyveromyces dominated. Isolation of the same species of microfungi from the integument of leeches and the river water suggests that Theromyzon maculosum may be a potential vector of pathogenic yeasts for vertebrates living in the same ecosystems and for humans.

New record of the fish leech Piscicola pojmanskae (Annelida: Hirudinida: Piscicolidae) - DNA barcoding and phylogeny

The aim of this study was to confirm the taxonomic status of Piscicola pojmanskae Bielecki, 1994 found on Salmonidae fish. The fish leech was identified based on a diligent morphological analysis as well as COI gene sequence (DNA barcoding). The phylogenetic relationship with other piscicolid leeches was analyzed as well. Piscicola pojmanskae was found on various fins of both graylings and the resident form of trouts. The prevalence of infection was 1.63%. In this paper, probable causes of the lack of relation between the number of leeches on the fins and the fish body length as well as the host-searching strategy used by P. pojmanskae are discussed.