Exposure to Macondo crude oil-derived WAFs induced diverse gross morphological deformations in zebrafish embryos. (A-F) Lateral and ventral views of live untreated control (A, B) and WAF-treated embryos (C-F) at 5 dpf. Severe cardiac and yolk edema (C, D, E, arrows), dorsal tail curvature (E, F, double arrows), and cysts at the tip of the tail (C, D, F, arrowhead) were visible. (G, H) WAF-treated embryos (H) had reduced jaws compared to controls (G, brackets). (G-J) At 3 dpf cardiac edema was evident in WAF-treated embryos (arrows), and 28% of embryos had hemorrhaging in the forebrain, midbrain and hindbrain (arrowheads). Lateral (G, H, I, J) and dorsal views (H', I', J'). (K-M) Retinal architecture appeared normal in control and WAF-treated embryos (K, L) but there was a slight reduction in the area and perimeter of WAF-treated retinas (M). Except for lens area, the size reductions were statistically significant (M, asterisks; t-tests: lens area, P = 0.015; lens perimeter, P = 0.007; retina area P < 0.0005; retina perimeter, P < 0.0005). Scale bars: 200 μm, F, J'; 50 μm, L. Abbreviations: gcl, ganglion cell layer; ipl, inner plexiform layer; inl, inner nuclear layer; opl, outer plexiform layer; onl. outer nuclear layer.