Olatunji Ayotunde,, E., Obeten Offem, B. and Bekeh Ada, F. 2012. Heavy metal profile of water, sediment and freshwater cat fish, Chrysichthys nigrodigitatus (Siluriformes: Bagridae), of Cross River, Nigeria. Revista de Biología Tropical. 60, 3 (Sep. 2012). DOI:https://doi.org/10.15517/rbt.v60i3.1807.