Endohelminth parasite communities of Squalius cii, including the zoonotic trematoda Clinostomum complanatum: Effect of host sex and size on community structure

Abstract

An examination was carried out from spring 2020 (April) to winter 2021 (February) to determine the occurrence of endoparasitic helminth in European chub ( Squalius cii) in the Susurluk basin from the Northwest region of Turkey. The infection levels of all identified endoparasitic helminths were also investigated in relation to host factors and seasons. In addition, the differences with their prevalence, mean intensity, and mean abundance were evaluated statistically. A total of 79 S . cii were examined, 33 fishes were found to be infected by one or more endoparasitic helminth specimens. Three species of endoparasitic helminth were identified on gill cavities and in the gastrointestinal tracts, respectively: Clinostomum complanatum (Rudolphi, 1814), Caryophyllaeides fennica (Schneider, 1902), and Rhabdochona denudata (Dujardin, 1845). R. denudata was the most common and most abundant species. The endohelminth infections were recorded in all seasons. C . fennica was recorded in spring and summer, while C . complanatum was encountered in spring and autumn, whereas it was not detected in summer and winter. The prevalences were higher in larger hosts based on body length in C . complanatum, C . fennica, and R. denudata, while a high mean intensity of C . complanatum and R . denudate was in smaller hosts. Male host fishes had higher prevalence levels of endoparasitic helminth infection. The present study provides the first record of the endoparasitic helminth of S. cii considered a valid species in Turkey and the first host record of three endohelminth species in S.cii.