Effect of sublethal concentrations of monocrotophos on erythropoietic activity and certain hematological parameters of fish Anabas testudineus (Bloch)

The indiscriminate use of pesticides in agricultural operation adversely affects the aquatic environment to a very great extent. The biological and environment persistence of organochlorine pesticides have led to the extensive use of less persistent, easily biodegradable organophosphates (Ahamed et al. 1987; Siddiqui et al. 1991). This poses a great danger to freshwater organisms including fishes. Monocrotophos (phosphoric acid dimethyl (1-methyl-3(methylamino)-3-oxon-propenyl) ester), commonly known as Azodrin, is one of the organophosphates widely used for the control of agricultural pests in India (Ray et al. 1985). In order to determine the subtle, non-lethal effects induced by sublethal concentrations of pesticides on the physiology of fish, it is necessary to monitor certain clinical parameters. The use of hematological methods as indicators of sublethal stress, can provide valuable information concerning the physiological reaction of fish in a changing environment. The physical and chemical properties of fish blood are very sensitive to environmental changes (Huges and Nemcsok 1988). The objective of the present paper was to evaluate the effect of sublethal concentrations of monocrotophos on erythropoietic activity and hematology of Anabas testudineus (Bloch).