THE TOXICITY OF ESSENTIAL ELEMENT (Zn) IN THE BLOOD PROFILE OF FRESH WATER TELEOST, CLARIAS BATRACHUS

Minerals such as zinc (Zn) are abundant in the Earth's crust, serving as cofactors for a variety of proteins and modulating immune functions, however, in high doses, it might cause toxic effects on the body. This study examined the effects of excessive Zn concentrations on fish hematological parameters. The authors employed fresh water fishes Clarias batrachus as an experimental model and treated them with three different concentrations of Zn. The treatment with Zn was done for total 28 days and hematological parameters were assessed at different time intervals. As compared to control, Zn treated fishes showed considerable changes in hematological parameters such as, Haemoglobin (Hb), total erythrocyte counts (TEC), total leucocytes count (TLC), erythrocyte sedimentation rate (ESR), packed cell volume (PCV), mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV). The present study showed that exposure to Zn could be linked to chronic and acute hematological toxicity in fishes in time and dose-dependent manner.