Acute LC50 and bioconcentration of Mercury Chloride in Rutilus frisii kutum

Abstract

To determine the acute toxicity and bioaccumulation of mercuric chloride in Rutilus frisii kutum, specimens of the fish were exposed to various concentrations of the chemical in water. We carried out ten treatments with three replicates and one control for each of the chemicals using the static O.E.C.D. method in 55 liter tanks each containing 14 fingerlings. During the experiments, the average pH was recorded as 7.8, total hardness was measured to be 255 mg/l, average water temperature was 27±1 degrees centigrade and dissolved oxygen was 7.2 mg/l. Mean LC50 values of Hgcl2 for juvenile R. frisii kutum with mean weight 0.2 grams were 0.102 and 0.086 mg Hg/l at 24h and 96h, respectively. The bioaccumulation values during 24h in muscle tissue, kidney and gill were 1.55, 16.1 and 22.7 mg Hg/l respectively. The values during 96h exposure were 2.8, 16.8 and 26.65 mg Hg/l in tissue, kidney and gill respectively. The bio concentration values for muscle tissue, kidney and gill during the first 24h were 14.75, 153.39 and 216.11 after 96h were 33.8, 198.1 and 313.5 times that of the environment. These results show the bioaccumulation to be the highest in gill followed by kidney and muscle tissue. The study suggested direct relationship between mercury concentration in and its bioaccumulation in the fish organs tissue.