Effect of DPHP on hemoglobin levels. Mean stained area of hemoglobin (±standard deviation) within 72-hpf embryos exposed to vehicle (0.1% DMSO), DPHP (250, 500, or 1000 μM), or 0.09 μM butafenacil (positive control) from 24 to 72 hpf (A), 30 to 72 hpf (B), or 48 to 72 hpf (C). Asterisk (*) denotes significant treatment effect (p < 0.05) relative to vehicle controls (0.1% DMSO).