Gastrointestinal parasites of fish as bio-indicators of the ecology of Chanchaga River, Minna, Niger State
Fish parasites are of particular interest in relation not only to fish health but also in the understanding of ecological problems. A study of the gastrointestinal parasites of fish as bio-indicators of heavy metal pollution in Chanchaga River was carried out from May-August, 2014. A total of 100 specimens were sampled which comprises of 4 species; Tilapia zilli, Auchenoglanis occidentalis, Clarias gariepinus and Mormyrus rume (25 samples each). The intestinal contents of the samples were analyzed, parasites found were the Nematodes, 52.00% and mean intensity of 57.03, Cestodes, 28.00%with 4.14 mean intensity and some unidentified species of insects and Copepods were 12.00% and a mean intensity of 7.85. The concentration of the metals (Fe, Zn, Cu, Cr&Mn) were determined using Atomic Absorption Spectrophotometer (AAS). Result showed no significant (P>0.05) difference in the heavy metal accumulation in the muscle of both the infected fishes and the uninfected ones, but there was a significant (P<0.05) difference in the metal concentration in the intestines amongst the fish species for Cu in T. zilli (0.83±0.01mg/g) and in A. occidentalis(0.02±0.01 mg/g). Among the species sampled for heavy metal in fish muscle M. rume had the lowest mean concentration (0.27±0.01 mg/g) while C. gariepinus had the highest (0.45±0.03 mg/g). This study has established the presence of gastrointestinal parasites in fish from Chanchaga River and also presence of heavy metal though in low quantity in the fish from the River thereby indicating that the river is slightly polluted.
Keywords: Fish parasites, Heavy metals, Gastrointestinal and Chanchaga River