Butafenacil exposure from 5 to 72 hpf under normal light conditions results in decreased circulation, increased pericardial area, and increased protoporphyrin accumulation. (A) Mean body length (±standard deviation), (B) mean pericardial area (±standard deviation), (C) mean circulation (±standard deviation), and (D) mean protoporphyrin accumulation (±standard deviation) following exposure to vehicle (0.1% DMSO) or 0.025–0.78 μM butafenacil. Numbers above each bar denote the number of embryos analyzed across three replicate beakers per treatment and 20 initial embryos per replicate beaker. Asterisk (*) denotes significant difference from vehicle controls (p < 0.05). (E) Representative images of protoporphyrin accumulation within a 72-hpf embryo exposed to vehicle (left) or 0.09 μM butafenacil (right) under light conditions; orange color represents autofluorescence above a threshold of 115 relative fluorescent units within the yolk sac (white arrow). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Butafenacil exposure from 5 to 72 hpf in the dark resulted in decreased circulation in the absence of effects on survival, pericardial area, and protoporphyrin accumulation. (A) Mean body length (±standard deviation), (B) mean pericardial area (±standard deviation), (C) mean circulation (±standard deviation), and (D) mean protoporphyrin accumulation (±standard deviation) following exposure to vehicle (0.1% DMSO) or 0.025–0.78 μM butafenacil. Numbers above each bar denote the number of embryos analyzed across three replicate beakers per treatment and 20 initial embryos per replicate beaker. Asterisk (*) denotes significant difference from vehicle controls (p < 0.05). (E) Representative images of protoporphyrin accumulation within a 72-hpf embryo exposed to vehicle (left) or 0.09 μM butafenacil (right) under dark conditions; orange color represents autofluorescence above a threshold of 115 relative fluorescent units within the yolk sac (white arrow). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Experimental design for identifying sensitive developmental windows of butafenacil exposure as well as the potential for recovery following transfer to clean water.