Fish species parasites: A review in Nigerian water bodies

Abstract

Parasitic infection constitutes a major threat to the well-being and productivity of fishery industries in Nigeria. The parasites have been found and reported in the wild and different culturing media. The effect of parasitism ranges from infliction of injuries on organs, reduction in population of fish, impairment of proper organ functions, and disturbance in the physiology of the fish. Its effects also include reduction of both biomass and weight through parasites feeding on the fish host. Parasitism in fish has been aided by various ecological factors such as rainfall, temperature, dryness, of water, PH, turbidity and a suitable intermediate host. However man made factors such as deposit of waste and faeces to some water  bodies also influence the prevalence of parasitism of fish. Parasites encountered by various investigators included Protozoans such as Ichtoyobodo necator Eimeria chrysichthyic, Hexaimita sp, Tricodina sp, Crytobia ubilans, and Trypanosoma. Worms found in fish included Nematodes such as Cammalanus, sp Spironoura sp, Procamalus laevionchus, Gnathostoma sp, Paracamallanus, Eustrongyloides, Trematodes encountered were Clinistomidae, Clinostomium tilapiae, Paramphistomium sp, Euclinustomium heterostomium, Allocreadium ghaensis, Sandonia sadanensis, and Polyoncobothrium clariae. Records of cestodes were Proteocephalus sp, Diphyllobothrium, Amonotaenia sp, Polyoncobothrion clariae.,  Monobothriode wordlandi, and Heterophyid fluke. Acanthocephalans recorded in fish included Neochinorhyncus rutili, Pomporhynchus Quadrigidae.The annelida recorded was the Leech. Some fish hosts inhabiting parasites in various investigations across the country included Clarias gariepinus, Clarias lazera, Synodontis sorex, Tilapia zilli, Oreochromis niloticus, Clarias Pachynema, Malapterurus electricus Heterobranchus brisordalis amongst other numerous fish species. There is need to constantly investigate parasitism of fish in Nigerian waters with the view of creating a data bank that will accommodate the diversity of fish parasites in Nigerian waters

Keywords: Parasites, Fish species, Water, Data bank, Diversity