A circadian clock drives behavioral activity in Antarctic krill (Euphausia superba) and provides a potential mechanism for seasonal timing

• DOI: 10.7554/elife.103096.3
• Publication Date: 2025-04-29T15:12:39Z
• Authors: Lukas Hüppe; Dominik Bahlburg; Ryan Driscoll; Charlotte Helfric...; Bettina Meyer
• Keywords: Antarctic krill; Biological clock; Euphausiacea

Antarctic krill is a species with fundamental importance for the Southern Ocean ecosystem. Their large biomass and synchronized movements, like diel vertical migration (DVM), significantly impact ecosystem structure biological carbon pump. Despite decades of research, mechanistic basis DVM remains unclear. Circadian clocks help organisms anticipate daily environmental changes, optimizing adaptation. In this study, we used recently developed activity monitor to record swimming individual, wild-caught under various light conditions across different seasons. Our data demonstrate how circadian clock, in combination light, drives distinct bimodal pattern activity, which could facilitate ecologically important behavioral patterns, such as DVM. Rapid damping flexible synchronization indicate that clock adapted life at high latitudes seasonal recordings suggest clock-based mechanism timing processes. findings advance our understanding high-latitude adaptation key species.