eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-02-06 5 1 125 134 6525 article E. I. Adeyeye 1 M. K. O. Arifalo 2 Department of Chemistry, University of Ado-Ekiti, P.M.B. 5363, Ado-Ekiti (Nigeria). Department of Chemistry, College of Education, P.M.B. 250, Ikere-Ekiti (Nigeria). Levels of cobalt, zinc, lead, manganese, copper, iron, sodium and potassium were determined by means of atomic absorption spectrophotometer in the fish organs (scales, gills, intestine, eyes, head and trunk muscle) of two different sized Oreochromis niloticus (L.) in a freshwater pond. Cobalt and copper were not detected in both the fish organs, stock water and associated sediments. Lead was not detected in water, sediments and smaller sized fish (SSF) but was found accumulated in some organs of the bigger sized fish (BSF). Metals most concentrated in the SSF were manganese and sodium while those most concentrated in the BSF were zinc, lead, iron and potassium. However, for all the metals detected, the BSF trunk muscle had the overall highest concentration but the lead level was below the deleterious level. Significant differences occurred in the sizes of the SSF and BSF; and also in the metal concentrations in the scales, gills, intestine, eyes, head, and trunk muscles of the two different sized fish at p < 0.05. https://www.biotech-asia.org/vol5no1/the-likely-influence-of-size-in-the-distribution-and-concentration-of-some-metals-in-the-organs-of-oreochromis-niloticus-l-fish-in-a-freshwaer-pond/ Levels of metals; different sized Oreochromis niloticus fish