Macro and Trace Element Accumulation in Edible Crabs and Frogs in Alaro Stream Ecosystem, Ibadan
The tissue accumulation of five macroelements (Na, Mg, K, Ca, Fe) and twelve trace elements (Vd, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Pb) were assessed in the organs of the edible frogs; Xenopus laevis and Rana esculentus, and whole body of the crab, Callinestes caught from Alaro Stream Floodplain (Ibadan, Nigeria).The liver of the edible frogs showed higher concentrations of Cu, Mo, and Cd, while Na, Mg, K, V, Mn, Fe, Co, Zn and Pb were higher than the other organs in Rana esculentus. In the liver of Xenopus laevis, Se and Ag were higher than the bone, gut, heart and muscle while Ag was the only trace element with the lowest concentration in the bones of the edible frog in contrast to Ca which ranked highest in the study. Ag was the least accumulated in the whole body of the crab, Callinestes while Ca was the highest mean level of 139364ppm in the study. Significant correlation was recorded between the bioaccumulated macro and trace elements in the crabs and frogs. With the exception of Ag, all the other trace elements exceeded the guidelines and standards given by the Federal Environmental Protection Agency of Nigeria. Public health consciousness and regular monitoring is therefore necessary in the consumption of these aquatic food resources. Macro and trace element accumulation in edible frogs and crabs in a contaminated watershed in the tropical region.
Keywords: macro element, trace element, edible frogs, crabs