Leeches as the intermediate host for strigeid trematodes: genetic diversity and taxonomy of the genera Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928

Abstract Background Leeches (Hirudinida) play a significant role as intermediate hosts in the circulation of trematodes aquatic environment. However, species richness and molecular diversity phylogeny larval stages strigeid (tetracotyle) occurring this group invertebrates remain poorly understood. Here, we report our use recently obtained sequences several markers to analyse some aspects ecology, taxonomy genera Australapatemon Cotylurus , which utilise leeches hosts. Methods From April 2017 September 2018, 153 were collected from sampling stations small rivers with slow-flowing waters related drainage canals located three regions Poland. The distinctive forms tetracotyle metacercariae supplemented adult Strigeidae specimens sampled wide range water birds analysed using 28S rDNA partial gene, second internal transcribed spacer region (ITS2) cytochrome c oxidase (COI) fragment. Results Among investigated leeches, type detected parenchyma musculature 62 (prevalence 40.5%) mean intensity reaching 19.9 individuals. taxonomic generic affiliation derived revealed occurrence two genera: Sudarikov, 1959 Szidat, 1928. Phylogenetic reconstructions based on rRNA ITS2 COI gene confirmed separation clades. Taking currently available data results into consideration, sequenced represents most probably Au. minor ; however, unclear phylogenetic relationships between burti reduce reliability conclusion. On other hand, basis sequences, previously published data, identified species: C. strigeoides Dubois, 1958 syrius 1934. This is first record host. Conclusions study suggest ecological niches life cycles cornutus (Rudolphi, 1808) strigeoides/C. potential serious evolutionary consequences for host–parasite relationships. Moreover, analyses corroborated polyphyletic character status separate position raabei Bezubik, within . demonstrate inconsistent resulting, opinion, limited availability fully reliable, comparative taxa GenBank. Graphical