Emre, NesrinAydogdu, NurtenEmiroglu, Özgür2024-11-262024-11-262023-01-011300-1590https://doi.org/10.12714/egejfas.40.4.02https://hdl.handle.net/11452/48520The present study investigated diplozoid parasites in an endemic species, Capoeta aydinensis Turan, Kucuk, Kaya, Guclu & Bektas, 2017 in Koycegiz Lake, near Mugla province (Turkiye). The aim of this research is to improve a record of diplozoid species occurrence in C. aydinensis, an endemic fish species by collecting data from a previously unexplored locality situated in a different geographical region of Turkiye. A total of 187 individuals of C. aydinensis were collected by using fishing nets from October 2019 to July 2020 and examined for the presence of diplozoid species. Only one species of diplozoid has been recorded, known as Paradiplozoon bliccae (Reichenbach-Klinke, 1961), which has been identified morphologically and confirmed through molecular analysis. The nucleotide sequences of the parasite's nuclear internal transcribed spacer (ITS2) gene marker were determined as well as phylogenetic analyses by using Bayesian inference (BI) analyses. On the basis of the molecular findings, the morphological identification of the diplozoid parasite species was confirmed. Of 187 fish sampled, 27 were infected with 117 P. bliccae, representing an abundance of 0.6, a mean intensity of 4.3 and a prevalence of 14.4%. The prevalence and mean intensity of infection were based on the season and sex of the host. The highest values of infection for prevalence, mean intensity and abundance were found in summer. Meanwhile, mean intensity and abundance of P. bliccae were higher in males, the prevalence was higher in females. To our knowledge, the present study is the first ichthyoparasitological study of C. aydinensis in Koycegiz lake, near the province of Mugla in Turkiye. Furthermore, sequence data of P. bliccae from fish hosts in this locality were reported to GenBank for the first time as part of this study. Therefore, this study widens the host range of this parasite species in Turkiye.eninfo:eu-repo/semantics/closedAccessHomoion monogeneaParasitesTurkeyKoycegiz lakeCapoeta aydinensisParadiplozoon bliccaeMolecular approachSeasonal effectsHost sexScience & technologyLife sciences & biomedicineFisheriesMarine & freshwater biologyFisheriesArticle00125512050000224425040410.12714/egejfas.40.4.02