Table 5.

Non-parametric Kruskal–Wallis One-Way Analysis of Variance Test on mean values of Cd, Hg and Pb for the kidneys of ten fish species from Aiba Reservoir, Iwo, Nigeria.

Fish species	Cd (ppm) Mean ± SE	Hg (ppm) Mean ± SE	Pb (ppm) Mean ± SE
Marcusenius senegalensis	0.010 ± 0.002	0.006 ± 0.002	0.010 ± 0.002
Labeo senegalensis	0.025 ± 0.005	0.015 ± 0.005	0.025 ± 0.005
Hepsetus odoe	0.016 ± 0.003	0.011 ± 0.003	0.017 ± 0.002
Chrysichthys auratus	0.012 ± 0.002	0.008 ± 0.002	0.010 ± 0.003
Chrysichthys nigrodigitatus	0.006 ± 0.002	0.003 ± 0.001	0.007 ± 0.003
Clarias ebriensis	0.050 ± 0.010	0.030 ± 0.010	0.030 ± 0.010
Channa obscura	0.035 ± 0.005	0.025 ± 0.005	0.045 ± 0.005
Tilapia zillii	0.063 ± 0.013	0.038 ± 0.013	0.113 ± 0.013
Sarotherodon galilaeus	0.022 ± 0.010	0.008 ± 0.006	0.061 ± 0.030
Oreochromis niloticus	0.046 ± 0.023	0.028 ± 0.015	0.031 ± 0.013
(df = 9) P-value	16.25 0.062	16.09 0.065	17.14 0.047