The inner hours determine the rise and landing of Krill in Antarctica

Krill Antarctica not only interacts with external environmental effects such as light or food. They also use their inner watches to adapt to the harsh conditions of the polar environment.

Individually, the Krill (Euphausia Superba) does not make much impression. With the maximum body length of six centimeters, only two weight of grams and transparent skin, it does not look very amazing. However, Krill plays a major role for life in the southern ocean. Billions of these small crustaceans are huge swarms that can extend several square kilometers away and are the most important food source for many predators.

A research team from Julius-MAXIMINIAANS-HIVRSITUTät Würzburg (JMU), in cooperation with the Alfred Winerner Institute, the Helmholtz Center for Polar and Navy Research (AWI), which is the Helmhulz Institute for Career Marine Diversity (HIFMB) in Oldenburg and The National OceanogroGude in the United Kingdom, which is looking for Marine to a course of the marine, which is close to Marine to a Couger of the Marine to the Marin inhabits.

The group was particularly interested in “its daily vertical deportation in the water column”, according to the study now Published In the magazine Elife.

Food on the surface, protection from predators in depths

“The Antarctic Carrel uses the dark cover at night to feed on microscopic algae on the sea. During the day, animals are then seeking a shelter of predators in deeper and darker layers,” says Lucas Hobby.

HüPPE is the first author of the study and a PhD student in the Department of JMU and Genetics. Betina Mayer (AWI, HIFMB) and Charlotte Formster, a former holder of this president and a great professor. The internal watches were the axis of Forster’s search for many years. Accordingly, this project focused on the issue of determining Krill migrations by internal watches.

Although Krill has a great influence on mixing water column and carbon transport to the depths of the sea with its daily migration, despite decades of notes, the accurate mechanisms of this immigration behavior have not been completely understood yet. For their study, the first-time research team-with a thunderbolt individual animal for different seasons in the special activity screen.

Notes with newly developed technology

The researchers first developed this screen in 2024. The new device makes it possible to record swimming activity for individual creatures in tubes filled with sea water. For his experiences, the Hüppe Krill from the southern ocean caught a commercial hunting bowl. On the plane, he was able to use the new technology to study the Krill movements that were caught under different lighting conditions and at different times of the year.

His notes showed that crustaceans were more active at night, which corresponds to the patterns of natural migration in the wild. These night activity patterns adapt to the changing night length throughout the seasons. In addition, Krill maintained a daily rhythm of activity even when kept in fixed darkness for several days.

A typical rhythm even in complete darkness

“The Krill shows in Antarctica a daily rhythm with an increase in swimming activity at night, which is well proportional to vertical deportation in nature,” says HüPPE.

Even in complete darkness, the animals have maintained this rhythm for several days – resistance to the use of an internal clock to adapt the climb and land with the rhythm of the night. Experiments also showed that Krill can synchronize her behavior with flexibility with long or very short days, which only occurs in polar areas.

Therefore, it is clear: “Krill does not interact with external environmental effects only such as light or food with their behavior. It also uses their inner watches to adapt to the harsh conditions of its polar environment,” says Forster, summarizing the main results of the study.

The importance of the environmental system and the climate

Even if the study is primarily interested in physiological processes within small marine creatures, the importance of its findings exceeds this.

“As a carbon basin, the southern ocean plays a major role in organizing global climate. This function is based on a productive functional ecosystem, in the middle of which is Krill in Antarctica,” Mayer explains. The optimal adaptation of Krill with its environment is a key condition in the Krill health stocks.

Since the changes in Krill groups can have long -term consequences for the entire ecosystem of the southern ocean, the best understanding of adaptation mechanisms is crucial in order to provide predictions about the future development of the population.

In their next project, scientists want to investigate the inner clock in more detail.

“We want to understand where the watch falls into the Krill brain and how the mechanism works at the level of neurons,” says Förster.

This will also focus on the issue of how the inner clock affects other important operations in Krill – such as reproduction and hibernation strategies.