10.22376/ijpbs.2019.10.1.p1-12 Volume 5 Issue 3 2014 (July- September) The lessThan i greaterThan in vivo lessThan /i greaterThan genotoxic potential of Stomp Xtra herbicides was evaluated in a freshwater fish lessThan i greaterThan Channa punctatus lessThan /i greaterThan by assessing mitotic index in the kidney cells and micronuclei in the peripheral blood cells. Fish were exposed to five sub-lethal concentrations of Stomp Xtra containing a.i. pendemethalin at 0.293 (10% of LC50), 0.587 (20% of LC50), 0.881 (30% of LC50), 1.174 (40% of LC50) and 1.468 (50% of LC50) mg/L. For genotoxicity assay, hematopoietic cells from the kidneys and caudal vein of exposed fishes were examined after 24, 48, 72 and 96 h of exposure. Decrease in mitotic index in the kidney cells and increase in frequency of micronucleated erythrocytes in the peripheral blood cells with an increase in concentration of the herbicide were observed in treated fish. Two-way analysis of variance test (ANOVA test) revealed statistically highly significant effect of concentration of the herbicide as well as duration of treatment on mitotic index and frequency of micronucleated erythrocytes. AMRITA MULLICK, ANAND M JHA AND OM PRAKASH SHARMA Stomp Xtra, Pendemethalin, mitotic index, micronuclei, kidney cells, peripheral blood cells 543-552