Toxic effect of malathion on acetylcholinesterase activity of liver, brain and gills of freshwater catfish Heteropneustes fossilis

Abstract

The   toxic  effects  of  malathion   were  evident   in  the   inhibition  of   acetylcholinesterase  activity   of  liver,   brain and gills   of   freshwater   catfish   Heteropneustes   fossilis.   Maximum   inhibition   of   77. 12%   and   72.83%   were recorded  in  brain  and  gills  respectively  after  72  hour  of  exposure  to  4.80  mg/l  pesticide.  However,  in  liver highest   inhibition    of   67. 81%   in    enzyme   level    was   noticed    at   6.50   mg/l   pesticide    concentration   after   24 hours  of  exposure,  beyond  which  fish  could  not  survive.   Pesticide  repressed  the  enzyme   activity  so  intensely that it showed no sign of return to normalcy. The fish also  elicited  dissociated  behaviour  with  increasing concentrations of pesticide toxicity.