Isolation and Identification of Ectoparasites and Endoparasites of Some Freshwater Fishes Collected from Kargo Dam, Jaji, Kaduna State, Nigeria

Abstract

Parasitic infection remains a persistent threat to fish health and productivity in Nigeria’s inland waters, yet many small dams and reservoirs remain unsurveyed for the parasites their fish stocks carry. This study examined the ectoparasites and endoparasites of five freshwater fish species from Kargo Dam, Jaji, Kaduna State, Nigeria (October 2025–February 2026). Two hundred and eighty fish were examined, Clarias gariepinus (n = 64), Oreochromis niloticus (n = 53), Labeo coubie (n = 49), Synodontis schall (n = 56) and Heterotis niloticus (n = 58), by dissection and microscopy, with findings tested using chi-square analysis. Overall, 141 fish (50.36%) carried at least one parasite, prevalence being highest in Heterotis niloticus (65.52%) and lowest in Labeo coubie (38.78%); the species difference was significant, χ²(4, N = 280) = 9.82, p = .044. In total, 257 parasites across seven taxa were recovered: four ectoparasites (127, 49.42%) led by Dactylogyrus spp. and Gyrodactylus spp., and three endoparasites (130, 50.58%) dominated by Camallanus spp. Both groups were unevenly composed, χ²(3, N = 127) = 16.15, p = .001 for ectoparasites and χ²(2, N = 130) = 15.98, p < .001 for endoparasites, though the ecto-endo split did not differ from parity, χ²(1, N = 257) = 0.04, p = .852. Fish stocks at Kargo Dam thus carry a fairly diverse, moderately heavy parasite burden broadly consistent with reports elsewhere in Kaduna State, with implications for fish health, aquaculture output and, given Clinostomum spp., food safety. Regular monitoring and improved water management are recommended.