Effect of cadmium chloride and ascorbic acid exposure on the vital organs of freshwater Cyprinid, <i>Labeo rohita</i>

Abstract

The present study was carried out to evaluate the impact of sub lethal concentrations of heavy metal, cadmium chloride (CdCl₂.H₂O), ascorbic acid (vitamin C) and their combination on Labeo rohita. The effect was investigated on the basis of histopathological examinations of control and experimental groups exposed to heavy metal. The acute semi statistical toxicity test for L. rohita revealed 96 h LC₅₀ value 22.92 mg L^-1 for cadmium chloride (CdCl₂.H₂O). 215 fingerlings of L. rohita were exposed to three different experimental conditions for 96 h: 11.46 mg L^-1 CdCl₂.H₂O, or 450 mg Kg^-1 ascorbic acid or combination of both these doses. No alterations were observed in gill sections upon comparison between treated and untreated groups. Congestion in sinusoids, fatty change, an increase in Kupffer cells and intrahepatic lymphocytes was observed in CdCl₂.H₂O treated group. In kidney sections of heavy metal treated group, degeneration of the glomerular tissue, occlusion in tubular lumen and necrosis were observed. Similar changes but in less severe form, as described above, were observed in the fish exposed to combination of CdCl₂.H₂O and ascorbic indicating that ascorbic acid do detoxify the effect of heavy metal to some extant. Our results indicate that cadmium chloride (CdCl₂.H₂O), if present in fresh water bodies, may act as strong toxic agent for L. rohita.

Keywords: Labeo rohita, cadmium chloride (CdCl₂.H₂O), ascorbic acid, histopathology