Antarctic krill are essential to the Southern Ocean ecosystem, and new research from Julius-Maximilians-Universität Würzburg (JMU) reveals how their internal clock helps them thrive in extreme polar conditions.
The study, published in eLife in April 2025, shows that krill use their internal clock to manage their daily vertical migration. This involves swimming to the surface at night to feed on algae and descending to deeper waters during the day to avoid predators.
Researchers tracked individual krill using a newly developed activity monitor. Even in constant darkness, the krill maintained a daily rhythm, demonstrating the existence of an internal clock. This adaptation is vital for their survival and significantly impacts the Southern Ocean's ecosystem and its role as a carbon sink.