RT Journal Article SR Electronic T1 Fisheries-induced evolution of the circadian system and collective personality traits JF bioRxiv FD Cold Spring Harbor Laboratory SP 622043 DO 10.1101/622043 A1 Valerio Sbragaglia A1 Jose Fernando López-Olmeda A1 Elena Frigato A1 Cristiano Bertolucci A1 Robert Arlinghaus YR 2019 UL http://biorxiv.org/content/early/2019/05/02/622043.abstract AB The circadian system is phylogenetically conserved across a wide range of taxa. It orchestrates organismal biological processes and is linked to life history and risk-taking behavior. Fisheries-induced evolution affects life history and may also alter behavioral traits in exploited populations. Thus, intensive and selective harvesting may lead to the evolution of the circadian system and thereby affect temporal organization of physiological processes. We present experimental results based on zebrafish (Danio rerio) selection lines exposed to either large or small size-selective mortality relative to a control, simulating evolutionary responses to intensive fishing. We show that size-selective harvest leads to evolution of life-history, risk-taking and shoaling behaviors, and importantly, also shifts the molecular circadian clockwork. Evolutionary effects of size-selective harvesting on risk-taking and shoaling were linked to daily activity rhythms in the small, but not in the large, size-selective mortality scenario. Both small and large size-selective mortality induced an evolutionary shift of the molecular circadian clockwork in the same direction in the brain and liver. Interestingly, the shifts in the molecular circadian clockwork disappeared in the clock output pathway, resulting in similar transcription profile among size-selective scenarios. We reveal that size-selective harvesting not only alters life-histories, but also leaves an evolutionary legacy in the behavioral and physiological machinery of exploited fish populations. These changes can affect catchability, yield, recovery and the way exploited fish population use space and time and maybe difficult to be reversed even when harvesting is halted.Significance statement Harvesting constitutes a strong driver of life history evolution in wild populations, but there is limited knowledge whether harvesting also leads to adaptive changes in the underlying physiology and behavior of exploited populations. We use a multi-generation zebrafish (Danio rerio) harvesting experiment simulating two different fisheries scenarios and we show that size-selective mortality affect the circadian system and collective fish personality traits. Such adaptations were present eight generations after size-selective harvesting was stopped, indicating induced evolution of the circadian system and behavioural traits in response to size-selective harvesting.