COMPARATIVE STUDY ON THE LEVELS OF HEAVY METALS IN THE BITTER LAKES AND LAKE TIMSAH, (SUEZ CANAL) IN RELATION TO THE REPRODUCTIVE CYCLE OF THE RABBIT FISH SIGANUS RIVULA TUS.

Abstract

The concentration s of Cu, Zn, Pb, Cd, Fe, Mn, Cr, Ni and Co in muscles, liver and gonads of the marine rabbit fish Siganus rivulaivs from the Bitter lakes and lake Timsah, (Suez Canal) were investigated seasonally, over the course of one year (November 2002 - August 2003). Muscles recorded the lowest concentrations of metals than other organs which ranged between 0.22-0.76 and 0.27 - 1.23, 1.95 - 3.67 and 3.01 5.08, 0.09 -0.43 and 0.24 -0.51, 0.04 -0.16 and 0.11 -0.37, 4.32 -5.66 and 5.01 - 10.33, 0.12 - 0.29 and 0.26 - 1.35,0.06 - 0.09 and 0.05 - 0.16, 0.02 - 0.39 and 0.03 - 0.51 and 0.05 - 0.24 and 0.06 - 0.31 jig/g wet weight for Cu, Zn, Pb, Cd, Fe, Mn, Cr, Ni and Co in Bitter lakes and lake Timsah, respectively. The highest concentrations of all studied metals were found in gonads. Variation of metals in fish muscles through different seasons indicated that the most studied metals exhibited their highest value during the hot seasons (spring & summer). Gonadosomatic index (GSI) and its relationship with metal accumulation was calculated for the studied fish. By using seasonal changes in the values of gonadosomatic index, it was found that their spawning season is during spring.