During Arctic winter, the sun disappears below the horizon for long weeks of “polar night.” But new research shows that tiny crustaceans in the Arctic Ocean somehow maintain their daily rhythms during these extended periods of darkness.
Most living creatures use sunlight to time their biological processes and behaviors. This becomes a challenge when there is effectively no sunrise or sunset—and even more so under the sea, where water dims what little light there is. But small, shrimplike animals known as Arctic krill, an important food source for many aquatic species, have developed a crafty adaptation to maintain their habits during the polar night.
“Biological clocks are how our bodies anticipate what’s going to happen next, like how we know to start getting hungry around lunchtime,” says University of Delaware marine biologist Jonathan Cohen, lead author on the new study. Krill behavior shows that the polar night has enough light to keep this biological timer ticking in some creatures.
Cohen and his colleagues studied the krill species Thysanoessa inermis in the laboratory and in its natural Arctic Ocean habitats off the Svalbard archipelago. They found not only that krill could detect minimal shifts in very scant light but that the electrical activity in their eyes heightened at night, suggesting increased light sensitivity.
The researchers are still unsure why krill continue swimming up and down during the very darkest nights. “If there’s no light, there’s no primary production and algal blooms—so there’s nothing for them to eat,” says Emma Cavan, a marine biologist at Imperial College London who was not involved in the study. “So why are they moving to the surface? It’s one of the big mysteries of vertical migrations.
France Dernières Nouvelles, France Actualités
Similar News:Vous pouvez également lire des articles d'actualité similaires à celui-ci que nous avons collectés auprès d'autres sources d'information.
Polar bears move into abandoned Arctic weather station – photo essayPhotographer Dmitry Kokh discovered polar bears living in an abandoned weather station in Kolyuchin in the Chukotka Autonomous Okrug of Russia
Lire la suite »
Polar bears move into abandoned Arctic weather station – photo essayPhotographer Dmitry Kokh discovered polar bears living in an abandoned weather station in Kolyuchin in the Chukotka Autonomous Okrug of Russia
Lire la suite »
Do fertility trackers and apps actually help when trying to conceive?Tracking a person's fertile window is big business these days, but do these expensive products actually work? Experts discuss.
Lire la suite »
Ryan Day Plans to Continue Running Ohio State’s Offense Even with Promotions of Tony Alford and Brian HartlineEven though Ohio State now has an offensive coordinator, passing game coordinator and run game coordinator, Ryan Day will continue to call the Buckeyes’ offensive plays.
Lire la suite »
Beyonce Is Ready for Valentine’s Day in Luxe Adidas x Ivy Park OutfitBeyoncé was feeling the love on Monday night (Jan. 31) when she shared a new series of Valentine’s Day-themed photos to her Instagram page.
Lire la suite »