Gastro-Intestinal Parasites of Some Cultured and Wild Fish Species in the Southern Part of Nasarawa State Nigeria

The ever-growing demand for animal protein to address the rising malnutrition indices of developing nations has led to the flourishing of the fishery and aquaculture industry. But the safety of these processed fish species which come from both wild and cultured sources has been of interest to researches for some time. A comparative assessment of the gastro-intestinal parasites of cultured and wild species of Clarias gariepinus and Oreochromis niloticus was therefore carried out in the Southern part of Nasarawa State. Microscopic examination of the guts of 90 fishes, comprising 60 Clarias gariepinus and 30 Oreochromis niloticus revealed the presence of helminths (cestodes, nematodes and trematodes), algae and some insect larvae. A total of 17 (18.88%) of Clarias gariepinus and 8 (8.88%) of Oreochromis niloticus were infected with gastro-intestinal parasites, giving an overall prevalence of 27.77%. Cultured Clarias gariepinus and Oreochromis niloticus were less infected with parasites than wild species with a statistical significance of P = 0.0034 in this relationship. Also, Clarias gariepinus were found to be more infected with parasites than Oreochromis niloticus. Different species of algae were found in Orechromis niloticus while various stages of insect larvae were found in Clarias gariepinus only; an indication of their feeding habit and the niche they occupy in the aquatic ecosystem. Trichinella specie was found in some of the Clarias gariepinus examined, emphasizing its carnivorous tendencies.