Fig. 1: Activity patterns of individuals in the nontidal and tidal populations of the control group under laboratory DD conditions.

a Mean locomotor distance of individuals in the control (left panels) and the treatment (right panels) of the nontidal (upper panels) and tidal (lower panels) populations. Error bars represent the standard error of the mean (SEM). Subjective day and night are indicated by grey and black bars above the patterns, respectively. The expected tide level in the laboratory is shown as a grey dotted line. b Mean power of LombâScargle periodogram analysis for each individual. Error bars represent the SEM.