Figure 7

The circadian rhythm assay for Fe₃O₄ MNPs-exposed zebrafish after 14-day exposure. (A) Comparison of chronological changes of the average speed in light and dark cycles. The grey area shows the dark period while the white area shows the light period. Comparison of the (B) average speed, (C) average angular velocity, (D) meandering, (E) freezing movement time ratio, (F) swimming movement time ratio, and (G) rapid movement time ratio at the light cycle. Comparison of the (H) average speed, (I) average angular velocity, (J) meandering, (K) freezing movement time ratio, (L) swimming movement time ratio, and (M) rapid movement time ratio during the dark cycle. The data are expressed as the median with an interquartile range and were analyzed by a Kruskal-Wallis test, which continued with Dunn’s multiple comparisons test as a follow-up test (n = 15 for control, n = 18 for 1 and 10 ppm MNPs-exposed group, * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001).