Prevalence and intensity of parasitic helminths of thicklip grey mullet Chelon labrosus in hosts in Beymelek Lagoon Lake in Antalya, Turkey, according to season, host size, age, and sex of the host

In this study, helminth parasites of the thicklip grey mullet (Chelon labrosus) in Beymelek Lagoon, Antalya (Turkey) were studied to determine the effect of seasonal changes and host size, age, and sex on the incidence of parasitic helminth infection. Three helminth species were identified: Ligophorus angustus Euzet Suriano 1977 (Monogenea) on the gills, and Saccocoelium obesum Looss, 1902 (Digenea) and Neoechinorhynchus agilis (Rudolphi, 1819) (Acanthocephala) in the intestine. Among these species, S. obesum was the most common species, with an overall prevalence and mean intensity of 42.7% and 13.6 ± 12.5 parasites/fish, respectively. L. angustus was the second most prevalent parasite, with an overall prevalence of 21.3%. The third most prevalent parasite was N. agilis, with an overall prevalence and mean intensity of 12.6% and 3.6 ± 2.1 parasites/fish, respectively. Regarding the effect of seasonal changes, the prevalence and mean intensity of S. obesum was highest in the summer and spring, respectively. For L. angustus, while the highest prevalence was observed in winter (40.6%), this species was not recorded in summer. The prevalence of N. agilis was rather low (41.6%) in spring, and this species was also not detected in summer. With regard to host size-related incidence, the differences in the abundance of the 3 species among 4 size classes were not significant (P 0.05). In contrast, there were significant differences in the abundance of N. agilis among the age groups (P = 0.33). As for the infrapopulations of the parasite species depending on the host’s sex, significant differences were found in the infrapopulations of L. angustus and S. obesum between the sexes (P 0.001 and P = 0. 007, respectively).