The Toxicity of 10W-40 Motor Oil on Zebrafish Early Life Stages

In this study, toxicity of water associated fraction of 10W-40 motor oil was investigated during the early life stages of zebrafish (Danio rerio). In 1.5-hour post fertilization (hpf), the fertilized zebrafish eggs were exposed to the oil fraction (1.25, 2.5, 5.0,10.0, 20.0 and 40.0 v/v) and were followed through 24, 48, and 72 hpf. The morphological endpoints of development toxicity of the oil in zebrafish embryos were observed under a stereomicroscope. Higher concentrations caused acute lethal effects, and lower concentrations caused sublethal effects, such as incomplete gastrulation, tail curvature, weak pigmentation, head malformation, pericardial edema, vertebra column defect and scoliosis. Moreover, with the increase of the oil concentration, the malformation rate increased. The hatching rate and body length were also decreased. Finally, it was found that the water associated fraction of 10W-40 motor oil affected the normal embryonic development of zebrafish.