New insights into the monogenean fauna and host-parasite associations of cyprinoid fishes from the Karakaya Dam Lake on the Euphrates river, Türkiye: First records

This is the first study on monogenean ectoparasites of five cyprinoid fish species Cyprinus carpio, Carassius gibelio, Carassius auratus, Acanthobrama marmid and Chondrostoma regium in the Karakaya Dam Lake, on the Euphrates river. Fish species were obtained from a commercial fisherman in the period from December 2024 to June 2025. Ten gill monogenean parasites belonging to three different genera (Dactylogyrus, Gyrodactylus, Eudiplozoon) were identified. These are Dactylogyrus anchoratus, D. anoigeus D. achmerowi D. extensus, D. elegantis, D. sphyrna, D. vistulae, Eudiplozoon nipponicum, Gyrodactylus sprostonae and Gyrodactylus sp. The percentage of occurrence, mean intensity and abundance values of the identified monogenean species in their hosts were calculated. The similarity of the monogenean parasite fauna of five cyprinoid fish species was compared. The most common monogenean species is D. anchoratus, which has been identified in Carasius auratus, C. gibelio and C. carpio. All the monogenean species were recorded for the first time in the Karakaya Dam Lake. Dactylogyrus anoigeus and D. achmerowi are new records for Turkish fish parasite fauna, while E. nipponicum for A. marmid and C. gibelio, D. sphyrna for A. marmid are a new parasite records. Furthermore, the D. extensus and G. sprostonae on C. auratus is reported for the first time in T & uuml;rkiye.