Two known mutagenic drugs, cyclophosphamide and vinblastine sulfate, were tested using the micronucleus test in the native fish species, Astyanax bimaculatus, in order to determine which of these drugs and the doses which would be the most adequate for use as positive controls in this species. This Brazilian fish species was chosen because few toxicity studies have used native fish species and this particular species is widely consumed in various regions of Brazil. Three thousand erythrocytes per specimen were scored. Doses of 16 and 8 mg/kg body weight of cyclophosphamide and vinblastine sulfate, respectively, were the most effective in causing micronuclei. Cyclophosphamide was the most mutagenic of the two drugs and is recommended for use as a positive control in A. bimaculatus.
