Bioaccumulation of Some Heavy Metals in Tissues and Head of Commercial Nile Fish in Sudan

Abstract

The concentration of heavy metals was determined in tissue and head of the Nilefish: Barbus bynni, Labeo niloticus, Marcusenius cyprinoides, Mormyrus niloticus, Clarias lazera, Mormyrops anguilloides and Protopterus annectens . Tissue and head contained (14.3 to 14.7 µg/100g) of (Be). The range of (Mo) was (3.5 to 16.25 µg/100g) in the tissue, high in M. anguilloides and low in P. annectens . The head of C. lazera contained the maximum level of (53.55 µg/100g). The level of (Ba) in the tissues was (22 µg/100g) in L. niloticus and C. lazera and (67.3 µg/100g) was detected in head of C. lazera . A level of (18.8 µg/100g) of (Si) was found in tissue of M. niloticus , and (23.5 µg/100g) in head, while B. bynni contained (26.75 µg/100g) in tissue. The range of (Mn) in tissue was (16.8 to 38.5 µg/100g), high of L. niloticus , and (41.5 to 89.85 µg/100g) in head, high in C. lazera and M. niloticus . Low level was found in both tissue and head of P. annectens . The range of (B) in the tissue was (62.25 to 80.8 µg/100g) maximum in M. a nguilloides and minimum in P. annectens . The range in head was (74.4 to 91.25 µg/100g), maximum in M. niloticus and minimum in M. a nguilloides . The present results revealed significant differences (p < 0.05) in the distribution of heavy metals between tissue and head. The head contained higher concentrations of Mo, Ba, Mn and B in all species. Boron was the most common heavy metals in both tissue and head followed by Mn, Ba and Mo. Bioaccumulation of heavy metals vary in different species. Protopterus annectens contained the least levels in both tissue and head. Bioaccumulation of heavy metals in fish can be considered as an index of pollution in the aquatic bodies. Regular monitoring of heavy metals in theNile and fish should be done to ensure continuous safety of food.