Adaptive changes in respiratory movements of an air-breathing fish, Anabas testtudineus exposed to organophosphate pesticide, monocrotophos

Behaviour is the recordable and observable activity of the living organisms. In the present study adaptive changes in respiratory movements of an air-breathing fish, Anabas testudineus exposed to sublethal concentrations 1.9, 4.75 and p.5 ppm (1/10, 1/4 and 1/2 of 96-hr LC₅₀) for 21 days were studied. Adaptive changes in the respiratory movements were estimated by measuring two parameters namely 'surfacing behaviour' and 'opercular movements'. Significant increase (P<0.001) in surfacing behaviour were observed in 1.9, 4.75 and 9.5 ppm monocrotophos treated fishes compared to control. Opercular movements with decrease (P<0.001) in all three sublethal concentrations compared to control.