Changes in selected biomarkers in freshwater teleost fish, Cyprinus carpio var. communis exposed to sublethal concentrations of chromium sulphate toxicity.

The toxicity of chromium sulphate on plasma electrolytes (Na+, K+, Cl-) level and Na+, K(+)-ATPase activity of an economically important fish, Cyprinus carpio var. communis was evaluated. During sublethal treatment, plasma sodium level was increased, whereas plasma chloride level decreased throughout the experimental period. Plasma potassium level increased upto 10th day and then declined in the rest of the study period. The Na+, K(+)-ATPase activity decreased upto 15th day of treatment and slowly recovered showing significant increase upto 25th day of treatment. The significant changes in the plasma electrolytes levels and Na+, K(+)-ATPase activity can serve as a valuable biomarker of pollutant exposure and effects.