Effect of temperature on zebrafish hatching rhythms.

<p>Fertilised eggs were incubated under LD (A), LL (B) and DD (C). Values are expressed as the percentage of newly hatched embryos observed every two hours, during three consecutive days (44 – 100 hpf). White and black bars represent the day and night phases, respectively. The arrow represents the time of fertilization. Data are expressed as mean±SEM. Different letters indicate statistical differences among groups at the specific sampling time (ANOVA, <i>P</i><0.05, N = 30 per temperature group). Abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052153#pone-0052153-g001" target="_blank">Figure 1</a>.