Hoplobatrachus occipitalis AND Clarias anguillaris AS SENTINELS FOR ASSESSMENT OF HEAVY METALS IN IRRIGATION WATER KADAWA KANO, NIGERIA

Abstract

This study was carried out to evaluate the concentrations of heavy metals (Cd, Cu, Mn, Pb, and Zn) in Crowned
bullfrog (Hoplobatrachus occipitalis) and African Catfish (Clarias anguillaris) in irrigation water Kadawa, Kano
State, Nigeria. Muscle, liver, lung, and gill were analysed for Cd, Mn, Pb, Cu, and Zn using Atomic Absorption
Spectrometer (AAS). It was revealed that Crowned bullfrog has the highest concentrations of Zn, Pb, and Cu with
mean values of 35.02 mg/kg, 0.81 mg/kg, and 0.39 mg/kg, the least in African catfish with mean values of 12.85
mg/kg, 0.53 mg/kg and 0.35 mg/kg respectively. The lung of crowned bullfrog has the highest concentrations of
Mn (0.68 mg/kg), Pb (1.81 mg/kg) and Zn (77.38 mg/kg) while the highest concentration of Cu (1.02 mg/kg), Mn
(7.57 mg/kg), Pb (1.09 mg/kg) and Zn (21.20 mg/kg) were recorded in the liver of African catfish. Concentrations
of Mn, Pb, and Zn in Crowned bullfrog, catfishes, and water samples were found to be above the permissible
limits set by FEPA (2003) and NESREA (2011). More accumulation of heavy metals was recorded in Crowned
bullfrog compared to African catfish, hence frogs may be considered as more sensitive bioindicators of heavy
metals compared to African catfish.