Marine researchers in Japan and elsewhere have discovered another riddle of the aquatic world. In a new paper published Thursday, they detail their discovery various species of large marine animals, from turtles to sharks and seals, swim in circles for no apparent reason. The circle could have several purposes for animals, such as supporting navigation or searching for food, the researchers say.
According to researchers, recent advances in technology have allowed scientists to get a more complete picture of how ocean animals move through them. environment with much better accuracy than before. Lead author Tomoko Narazaki, of the University of Tokyo, and his colleagues they decided to develop this technology by looking at the movements of green turtles during the nesting season, when female turtles return to their place of birth to lay eggs.
They moved the turtles from their nesting location elsewhere so that they could observe how they sailed back to their original place. But once they did, they noticed a special pattern: turtles often rotated at a relatively constant speed at least twice, then returned to normal swimming. as they ventured back The home.
Curiously, Narazaki told others in his field about the discovery. Finally, he teamed up with some of these researchers to look back at the movement data that was collected earlier. a range of other marine animals in different branches of the evolutionary tree. And they certainly found that the same kind of behavior in the circle occurs repeatedly. These animals included fish (tiger sharks), birds (king penguins) and mammals (Antarctic fur seal and Chumpback whales).
Their job is published in iScience.
“All data used in our study were initially collected for different purposes (e.g.g., to study the feeding behavior of sharks, etc.). The data of each species were analyzed by different co-authors for different aspects “, Narazaki told Gizmodo in an e-mail. “It simply came to our notice then a time for us to realize that this circle is a common behavior in many species – until we collaborated ”.
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On the surface, surrounding it is practically impractical for the survival of these animals, as the most energy efficient way to travel anywhere in the ocean is usually a straight line. So that probably means it has one or more important functions that are worth the extra effort. Currently, however, the whole team has some educated assumptions about what is happening, which can vary between different species.
Sharks, for example, seem to revolve most often around where they receive food, indicating that it offers a certain advantage in hunting. Meanwhile, other research has had DISPLAY that some whale species will use the circle in groups as a way to create “bubble nets” to catch their prey from small fish. But feeding is probably not the only purpose for circulation.
In at least one male tiger shark, the team found evidence that the circle is part of it courtship ritual in front of a woman. Seals and penguins most often appear to move near the surface of the water or outside their typical holes.ging hours, both indicating that it is not part of their feeding technique. The team also cited previous research that found that northern elephants will circle during drifting dives – lazy, passive dives that help them rest or process their last meal.
In turtles, circling can help them reorient their navigation skills, which are based on on smell, sight and feeling magnetic fields. The turtles would move frequently just before the last part of their journey and, for a while, also. It was observed that a turtle circled 76 times before moving on.
“Given that similar circle behavior has been observed in a wide variety of marine megafauna taxa, there may be behavioral convergence with similar purposes,” Narazaki said. “But for now, the purpose and function of this behavior remain unknown.”
Of course, we know that a lot of animals on land move for various reasons (ask yourself the nearest dog before poop). But the darkness of the vast ocean means that there are probably all sorts of mundane behaviors among these animals that we simply have not come to see. yet. Studying how and why marine moving closer, researchers hope to shed a little more light on this almost extraterrestrial world.
“For the next step, we would like to examine the movements of the animals in relation to the internal condition of the animals and the environmental conditions to examine why they move,” Narazaki said. “Some hypotheses-Experimental testing would be necessary to understand the function and mechanism underlying encirclement movements. ”