Specimens injected intramuscularly with double DW (being the ‘‘vehicle’’ of EMS) and with 1% Alc
(being the ‘‘vehicle’’ of BC) at 1 ml/100 g bw served as controls. The nonnatural route was favored because the genotoxic effects or their ameliorations could be correlated for the exact dose of test chemicals injected into the body rather than leaving the fish to ingest these either with food or water resulting in differential intake/assimilation or removal through feces/excretion for different specimens. Besides, the possibility of differential absorption through surface and the management problem related with periodical changes of water medium with the test chemicals could also be avoided by the injection route.