M. Santhakumar, M. Balaji, and K. Ramudu
Abstract
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 testudinens 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 Hopercular 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.