Remediation of toxic effect of Mercuric Chloride on the Nile Tilapia, Oreochromis niloticus using Selenium

A.  El-Matary, Fatma; S. Beheary, Mokhtar; O. Barakat, Rania; A. Elgamal, Abd El-Hakim

doi:10.21608/ejabf.2019.33802

Remediation of toxic effect of Mercuric Chloride on the Nile Tilapia, Oreochromis niloticus using Selenium

Document Type : Original Article

Authors

10.21608/ejabf.2019.33802

Abstract

The present results showed that heavy metals (HgCl₂) have affected the biological parameters of Oreochromis niloticus. These effects depended on the duration of the exposure and the concentration of the heavy metal used. The effect of various doses level of HgCl₂ on the erythrocyte count (Red blood cells) decreased under the effect of the high doses of HgCl₂ (0.08 mg/l or more). A significance difference was recorded in comparison with the control fish (p<0.05).The total white blood cells counts significantly increased as the concentration of HgCl₂ increase when compared to the control fish. In contrast, hemoglobin (Hb) levels significantly (p<0.05) decreased after the fish exposed to high level doses of HgCl₂. Addition of selenium (Na₂SeO₃) at doses of 1.0 and 2.0 mg/kg to fish food for a period of 20 days of treatment with HgCl₂ improved blood constituent. Treated gills with high doses of HgCl₂ showed alteration on both of primary and secondary lamellae and an increase in the mucous secretion when compared with the control tissue. No abnormalities occurred in the liver of control fish. The main alterations in the liver of fish were observed after treatment with high doses level of HgCl₂ (0.06-0.08mg/l). The hepatocytes were hypertrophied and the nuclei showed necrosis.

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