ALTERATION IN THE CAUDAL NEUROSECRETORY SYSTEM DUE TO EXPOSURE TO ENDOSULFAN AND MALATHION IN THE FRESH WATER FISH HETEROPNEUSTES FOSSILIS

Effect of two pesticides endosulfan and malathion on the caudal neurosecretory system of freshwater catfish Heteropneustes fossilis, exposed for 7 and 15 days durations, are observed and discussed in reference to ionohydrosomotic role of urophysial system. Both pesticides could initially induce the neurosecretory activity of Dehlgren cells, however, in Malathion exposed fish even chromophobia could settle following 15 days exposure. It seems that such rise in neurosecretory activity contributes either to the tendency of rapid excretion of pesticides or towards counterbalance of blood pressure risen as a pesticidal exposure effect.