Parasitic Prevalence in Common Carp (Cyprinus carpio) Cultured in Ponds in Kaduna State, North West Nigeria

This study determines the parasitic fauna and prevalence in common carp Cyprinus carpio cultured in earthen ponds in Kaduna State, located in Nigeria's North West geopolitical zone. Common carp is one of the most widely cultured fish species in Nigeria, and parasitic infections in pond culture represent a significant threat to production and farmer profitability. Fish were sampled from 12 earthen ponds across Soba, Zaria, and Kauru local government areas. A total of 180 fish were examined using standard parasitological dissection, scraping, and microscopic examination of gills, skin, and gastrointestinal tract. Water quality parameters were recorded at each pond. Overall parasite prevalence was 64.4 percent. Nine parasite species were identified, including ectoparasitic Dactylogyrus spp. and Ichthyophthirius multifiliis on gills and skin, and endoparasitic nematodes and cestodes in the gastrointestinal tract. Dactylogyrus vastator was the most prevalent parasite (46.1%). Ponds with higher stocking density and poorer water quality (low dissolved oxygen, high ammonium) had significantly higher parasite intensity. Ichthyophthirius infections were associated with acute gill damage and mortality events in three ponds. The study recommends stocking density reduction, water quality management, and strategic chemotherapy using salt baths and formalin treatments for disease prevention in Kaduna State carp culture. Keywords: Cyprinus carpio, parasitic prevalence, aquaculture, Kaduna State, Dactylogyrus.