The fin fish assembage of Ikere Gorge, Oyo State, Nigeria

The fin fish assemblage of Ikere gorge was investigated. The fin fishes comprised a total of 34 species belonging to 13 families. Chrysicthys nigrodigitatus was most abundant and highest in biomass (69,198.33 kg) accounting for 34.65% of the catch. Synodontis nigrita, Malapterurus electricus, Marcusenius psittacus Gnathonemus sensgalensis and Gnathonemus cyprinoides were the least in number, while Phago loricatus was least in biomass (20.00 kg) accounting for 0.01%.The major aim was to assess the fish resources of the gorge and evaluate the water parameters as related to fish production. No significant difference was observed in dissolved oxygen, nitrate, phosphate, water temperature, conductivity, alkalinity, total dissolved solid and pH range value in the stations. The water quality parameters were favourable for fish production. Water level and temperature were observed to guarantee high fish yield in the gorge

Heavy metals concentrations in Chrysichthys nigrodigitatus in Arakanga Reservoir, Abeokuta, Ogun State, Nigeria

This study investigates the morphometric and meristic features of Chrysichthys nigrodigitatus in relations to heavy metal concentrations. Varying sizes of Clarias nigrodigitatus were obtained with the help of fisher-folks, from Arakanga reservoir Ogun state, Nigeria. Water samples were also collected alongside with fish samples per week and five of the samples were sent to laboratory for analysis to determine the presence of four heavy metals in both fish and water. Lead, Cadmium, Nickel and Arsenic were investigated by atomic absorption spectrophotometer (AAS). Four tissues; gills, kidney, liver and muscle were compared with the level of metals in the water. Lower concentrations of metals were recorded in water except for Cadmium which is higher, than in fish. Lower concentration of heavy metals found in fish and water was less than that recommended by the World Health Organisation (WHO's) guideline for maximum concentration recorded in the tissue of the samples. Lead was found to be dominant in the gills of C. nigrodigitatus, while Cadmium was found to be highest in the water sample from Arakanga reservoir. There is significant difference (P<0.05) in Nickel and Arsenic concentration in the tissues of C. nigrodigitatus and water. It was concluded that though the heavy metals of interest were present in measurable quantities, they were still within safe limits for consumption

The effects of heavy metals concentration in some commercial fish in Ogun River, Opeji, Ogun State, Nigeria

A study was conducted on commercially important fish species of heavy metals in water bodies, The primary objectives were to find out the amount of heavy metals concentration in the fish species, sediments and water samples at the deep and shallow part of the river, to determine the toxicity and relationship between the collected samples and the rate at which it pollutes the water. Atomic Absorption Spectrophotometer (AAS) evaluate their wholesomeness for human consumption. Four heavy metals (Lead, Cadmium, Copper and Zinc) were analysed and only Copper and Zinc were found to be present in the digested samples. The concentration of Copper in the fish (flesh) is 0.09mg/l and that of Zinc is 0.25mg/l. In the bone samples, Copper was found to have 0.17mg/l and Zinc to be 0.22mg/l. In the water samples analyzed, the concentration of Copper is 0.035mg/1 while that of Zinc is 0.047mg/l. In the sediment sample, the amount of Copper is 310.0mg/kg while that of Zinc is 20.50.0mg/kg. This however signifies that the fish species in the Ogun River as well as the water is suitable for consumption which was found to be less than the World Health Organization (WHO's) maximum recommended acceptable limits in the food