ABSTRACT
The present experiment has been designed to find out the effect of heavy metals on the immunological parameters of Labeo rohita and Catla catla as these are major pollutants of the fish habitat. The effect was observed on mean W B C count, lymphocyte and neutrophil count and other related parameters like general behaviour and stress on the controlled and experimentally exposed fishes to sub-lethal concentration of cadmium. Observations were-decreased in mean W B C and percent lymphocyte count, whereas neutrophilia was observed in both the species when exposed to sublethal concentrations of cadmium. The agglutination test conducted on the fishes exposed to cadmium revealed that the titre were higher in the exposed fishes indicating that the fishes are under stress. The study is relevant in the light that the pollutants causes sufficient stress to fish and ultimately affects its performance to harvest he benefits in the form of growths etc