First data of ITS1-genotyping of the Black Sea trematodes Cainocreadium and Helicometra (Trematoda: Opecoelidae)

Data of genetic analysis of the Black Sea trematodes of Cainocreadium genus and Helicometra fasciata were obtained for the first time. The nucleotide sequences of ITS1 rRNA gene cluster of Cainocreadium flesi from Platichthys flesus (GenBank entries MG980645, MG980646) and Cainocreadium sp. from Gaidropsarus mediterraneus (MG980643, MG980644, MK248037, MK248038) off Crimean Black Sea coast were found to be identical. Nevertheless, they have not been synonymized because of morphological differences known between these hostal morphs. Sequences of Cainocreadium from the Black Sea fish turned out to differ, by 4 positions, from similar sequences of a closely related Mediterranean congener, C. labracis (cercaria). Five insertions-deletions and 38 nucleotide sequences distinguish the ITS1 sequences of the Black Sea trematodes, C. flesi and Cainocreadium sp., from ITS1 sequences of another Mediterranean congener, C. dentecis. The ITS1 sequences of the Black Sea and Mediterranean Helicometra fasciata samples also differ: 5 nucleotide changes and 11 insertions-deletions were identified. Supplementary data associated with this article can be found in online version at https://doi.org/10.21072/mbj.2018.03.4.04.