Perfluorinated compounds are ubiquitous in our environment, exerting teratogenic and neurotoxic effects in wildlife including fish. These compounds can be produced as by-products from industry or produced through waste sewage and landfills. The Environmental Protection Agency seeks to collect both analytical and biological toxicity data for these compounds in order to better regulate them and assess risk. The objectives of this project will be to assess the acute toxicity of perfluoroheptanoic acid and perfluoropentanoic acid to zebrafish embryos by measuring mortality, morphological deformities, oxidative respiration, gene expression, and behavioral outcomes, specifically locomotor activity via the Visual Motor Response test. Zebrafish will be used in this study because they possess a high degree of genetic similarity to humans and are widely used as a model for disease in toxicological research. Zebrafish embryos at 6-h post-fertilization (hpf) will be exposed to either embryo rearing medium (ERM), or one dose of 2.5, 5, and 10 μM perfluorinated chemicals for 7 days post-fertilization (dpf). Deformities such as spinal curvature, pericardial edema, and yolk sac edema will be quantified following the exposure to perfluorinated chemicals. Oxidative respiration assessments in embryos will assess toxicity by examining basal respiration, ATP-linked respiration, and non-mitochondrial respiration. Gene expression analysis will be conducted on 7-day larvae for genes associated with behavior, such as dopamine transcripts (dopamine receptor genes and transporter). On day 7 of the exposure, a Visual Motor Response test will be conducted in two independent trials to determine whether perfluorinated compounds (1-10 µM) alters locomotor activity. These data are expected to improve understanding of the potential risk of perfluorinated chemicals to fish and will contribute to environmental risk assessments for the perfluorinated chemicals and phenylurea herbicides as a whole, on aquatic organisms.