The primary effects of embryonic fish exposed to Iranian Heavy crude oils

Abstract

Our previous studies using zebrafish demonstrated that exposure to the Iranian Heavy Crude (IHC) oil exposure cause carcinogenic edema and morphological damage. To clarify the effects of spilled oil on resident fish development, spotted perch (Lateolabrax maculates) and olive flounder (Paralichthys olivaceus) embryos (48 hr post-fertilization) were exposed to oiled gravel effluent of IHC oil for 48 hr. Embryos were manually dechorionated and observed by a stereomicroscope and a compound microscope. Embryos were fixed in 4% phosphate-buffered paraformaldehyde and stained for CYP1A and myosin heavy chain. After 24 hr, several complex effects, including the edema and tail mutant were observed in olive flounder embryos exposed to IHC. The distribution of CYP1A in embryo was assessed by immunofluorescence. CYP1A immunofluorescence activity was high significantly in the endothelium of head, epidermis and endocardium and a significant induction in CYP1A mRNA was observed in both of embryos after the oil exposure. Our results confirm that fish embryos exposed to the IHC may disrupt the cardiac function and shape of fish tail during development, which is highly relevant for fitness and survival.