Fish is considered a profitable animal that provides a cheap source of proteins. Various parasites affect the fish fauna which badly affects fish tissues and stops productivity. This study explores the ectoparasites and intestinal parasites of Ctenopharyngodon idella from lentic reservoirs, in Pakistan. The collection of samples was done by simple hand net. The samples were examined at the University of Malakand. Out of 100 specimens, 30%(n=30) were found to be infected with ectoparasites while 60% (n=60) were have been observed with Annelids and helminths. The species-wise prevalence of ectoparasite is 30% (Lernaea spp.), 45% of (Aeolosoma spp.), and Nematode parasite showed 15% as Rhabdochona spp. The higher intensity was recorded for Aeolosoma spp. (3.0). The sex-wise prevalence of parasites was higher in female specimens. The length weight-wise prevalence of the parasite was recorded higher in fish with maximum length and high body weight compared to small size and low body weight fish. The age-wise prevalence of ectoparasite was revealed higher in adult fish and endoparasites were found higher in sub-adult fish. The season-wise prevalence of parasites was recorded higher in the summer season. This study concluded that the gastrointestinal helminth and Annelids were more prevalent than ectoparasite in lentic reservoirs.

keywords: Fish; grass carp; ectoparasites; helminth parasites; Annelids; lentic reservoirs