Document Type : Research Paper
Authors
1 Department of Biology, Alzahra University
2 Department of marine biology science and research branch Islamic Azad university
Abstract
A series of specific toxicological effects including bioaccumulation of the pollutant, histological changes and influences on ovary tissue were examined in the Rutilus rutilus after the exposure to graded sublethal concentrations (10 , 30 , 50 μg Hg/L) of mercury chloride (MC). Histopathological changes, such as telangiectasis, and degenerative, can clearly be observed in the slices from the ovary exposed Roach.
A batch of Roach with the mean values of 5 cm in length and 5.5 g in mass were pre-raised in a static system, which was supplied with dechlorinated tap water and constantly aerated. The water qualities were controlled as follows: pH, 7.45; oxygen concentration, 7 mg/L; the water temperature, 21–22 ◦C. All fish were fed twice a day with a commercial ration of biomar. Reagents Appropriate amount of mercury chloride (MC, AR 98%, Merck-Schuchardt) was dissolved in a stock solution of 0.676g HgCl2/L.
Based on the 24 h LC50 value (70 ppb) obtained from the acute exposure test, a graded series (10 , 30 , 50 μg Hg/L) of mercury chloride (MC) were administered to Roach fish (Rutilus rutilus) with 48 fish per group. The chemical exposure experiments lasted for 48 , 96 and 144 hours. These designed exposure levels were sublethal, and could induce obvious alteration of tissues abnormalities and disease at the same time.
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