This study assessed the transcriptional effects of chemical oil dispersion on oil toxicity in mahi-mahi embryos/larvae. Although much work has focused on the effects of Deepwater Horizon oil on fish in the Gulf of Mexico, few studies have assessed the effects of chemical dispersion on oil toxicity in pelagic species of the region. Beginning ~8 hours post fertilization, mahi-mahi embryos were exposed to varying concentrations of dispersant alone or in tandem with oil for 48 hours. Following exposure the surviving larvae were collected and used for RNASeq. Phenotypic endpoints such as mortality, pericardial edema, yolk sac edema, and eye size were also assessed.