MORPHOLOGICAL AND MOLECULAR DIFFERENTIATION OF Clinostomum complanatum (Digenea: Clinostomidae) METACERCARIAE INFECTING Cyprinus carpio IN ARAS RIVER

Clinostomiasis is one of the parasitic diseases infecting freshwater fish caused by digenean trematode of the Clinostomidae family. In this study a total of 100 fish belonging to the nine species were collected from Aras River in 2021-2022. The collected fish then analyzed for infection with Clinostomum complanatum (C. complanatum) metacercaria. The partial mitochondrial COX-I gene were amplified for sequencing and phylogenetic analyses. Only one specimen belonging to Cyprinus carpio were found to be infected with metacercariae with the prevalence of 5%. The sequence analysis confirmed morphological identification as all metacercariae were belonging to C. complanatum with homology of 100% with other sequences of C. complanatum available in the NCBI database. The present study reports the first case of C. complanatum in Cyprinus carpio in Iran by morphological and molecular methods and emphasizes the possible risk of transmission for consumers. Morfološka in molekularna diferenciacija metacerkarij Clinostomum complanatum (Digenea: Clinostomidae), ki invadirajo Cyprinus carpio v reki Aras Izvleček: Klinostomoza je ena od parazitskih bolezni sladkovodnih rib, ki jo povzročajo digeni trematodi iz družine Clinostomidae. V raziskavi je bilo v letih 2021–2022 v reki Aras ulovljenih 100 rib, ki pripadajo devetim vrstam. Ulovljene ribe so nato analizirali na prisotnost metacerkarij Clinostomum complanatum (C. complanatum). Delni mitohondrijski gen COX-I je bil pomnožen za sekvenciranje in filogenetske analize. Z metacerkarijami je bil invadiran le en primerek, ki je pripadal Cyprinus carpio, in sicer s 5-odstotno prevalenco. Analiza zaporedja je potrdila morfološko identifikacijo, saj so vse metacerkarije pripadale C. complanatum s 100-odstotno homologijo z drugimi zaporedji C. complanatum, ki so na voljo v podatkovni bazi NCBI. Pričujoča študija poroča o prvem primeru C. complanatum pri Cyprinus carpio v Iranu z morfološkimi in molekularnimi metodami ter poudarja morebitno tveganje prenosa na potrošnike. Ključne besede: Clinostomum complanatum; Cyprinus carpio; reka Aras; Ardabil