Basal and 3-methylcholanthrene-induced expression of cytochrome P450 1A, 1B and 1C genes in the Brazilian guppy, Poecilia vivipara

► P. vivipara is a suitable model for environmental toxicology studies in Brazil. ► We cloned P. vivipara CYP1A with 91% identity to F. heteroclitus biomarker CYP1A. ► All tissues examined showed basal levels of CYP1A, CYP1B1 and CYP1C1. ► 3-MC induced CYP1A, CYP1B1, and CYP1C1 significantly in all organs examined. ► Fish from a polluted mangrove showed induction of CYP1s in gill and liver.