DISTRIBUTION OF MERCURY IN TISSUES OF THE COMMON CARP (CYPRINUS CARPIO L.)

The aim of the experiment was to determine the distribution of mercury in ten selected tissues (muscle, skin, fish scales, biliary vesicle, brain, eyes, kidneys, spleen, liver and gills) of common carp (Cyprinus carpio L.). Carp fingerlings weighed 47.67 +/- 4.61 g. Carps were exposed to increasing concentrations of mercury (0 mu g. l(-1) (control), 0.5 mu g . l(-1), 1.5 mu g . l(-1) and 3.0 mu g . l(-1)) in fish tanks for 14 days. The concentrations of mercury in fish tanks were continuously monitored and in case of a change they were adjusted to an acceptable value. The fish were not fed during the experiment and mercury got accumulated in fish tissues from fish tank water only. Five fish were collected on the 0th, 4th, 9th and 14th day of experiment from each concentration for the analysis of total mercury content in selected tissues. Total mercury content in water and in selected tissues was determined by the atomic absorption spectrometer AMA 254. The increase of mercury in all tested tissues was not observed in the control group during the 14-day experiment. The time linear increase of mercury content was observed in the muscles, skin, fish scales, biliary vesicle, eyes, kidneys, spleen and gills in all three mercury concentrations under testing. The lowest mercury concentrations were determined in the control group in the range of 0.004-0.052 mg . kg(-1). Compared to this group, the highest concentration of mercury was found in kidneys (for fish tank with 0.5 mu g . l(-1) the mercury concentration was 1.405 +/- 0.300 mg . kg(-1), for fish tank with 1.5 mu g. l(-1) the mercury concentration was 5.537 +/- 0.027 mg . kg(-1) and for fish tank with 3.0 mu g . l(-1) the mercury concentration was 25.209 +/- 2.152 mg . kg(-1) on day 14 of the experiment).