Normalized plots of activity over a 72 h period under light-dark (LD), constant dark (DD) or constant light (LL) conditions following field or laboratory entrainment of Nematostella. y-axis shows activity as a proportion of the maximum activity observed for each animal. Bars above plots indicate light daytime (white) and dark night-time periods (black). Gray bars indicate daytime under DD or night under LL. x-axis shows hours since start of behavioral monitoring, with label spacing reflecting the timing of light changes in autumn and lab experiments. Plots show mean±s.e.m. of tracks from multiple individuals. Sample sizes indicated in Table 1.

Heat maps comparing selected transcriptional profiles between lab-entrained and field-entrained Nematostella. Lab data from Oren et al. (2015; 1 replicate derived from 5 pooled anemones per time), and field data from present study (four biological replicates per time). Color scale ranges from red to green (highest to lowest mean relative expression). Time of sampling is shown as Zeitgeber time (ZT), which is the number of hours since sunrise or the start of a light cycle. Black and white bars indicate time points that were sampled during the dark and light phases, respectively. Selected transcripts play putative roles in (A) regulation of the core circadian machinery and (B) the unfolded protein response.