Among the wonders of the natural world that few people have noticed: the moving semi-aquatic springtail.
There are about 9,000 known species of springtail – small, flea-like invertebrates – around the world. Many live in dark and humid habitats, but they can be found on all seven continents; Some even migrate on snow. Arthropods roamed the Earth by flinging their bodies in the air, sometimes spinning 500 times per second, like circus performers shooting from free-standing canons. Good luck taking a look at the hammock show — most springtails are “as small as a grain of sand,” said Victor Ortega Jimenez, a University of Maine biomechanics researcher who studies the creatures.
Now, a series of zoomed-in slow motion videos of these high-octane jumps, released by Dr. Ortega Jimenez and colleagues at article Published Monday in the Proceedings of the National Academy of Sciences, it reveals an element of little physical control that’s almost agile. The visuals help with a detailed explanation of how the tail spring jumps through the air and ends up on their feet almost every time they land.
Dr. Ortega Jiménez said the dominance of the pulsating tail came in large part from their most distinctive and mysterious feature, the colophore, a tube emerging from their stomachs. This tube interacts in different ways with the forces surrounding animals: drag, surface tension, gravity. “They’re taking advantage of the water and the air,” said Dr. Ortega Jimenez.
The pulsating tail is not insects, although it has long been classified as such due to its six legs, segmented bodies, and antennae. Because of their mouths, which have retracted inside their heads, they now make up the majority of a different taxonomic class: entognatha.
Taxonomically, the springtail is called Collembola, a designation given to it by John Lubbock, an English polyglot of the 19th and early 20th centuries. The word comes from the Greek words meaning “glue” and “peg”. Lubbock chose the name from the behavior he observed after turning a spring on their backs and flying a piece of glass over their stomachs. The animals would reach the shell with their legs while at the same time emitting fluid from the edges of their edges and pushing it toward the surface. This questioner, Lubbock Wrote“Without a doubt, it gives a better chance.”
Other scholars later disputed this interpretation of the colophore function. In the twentieth century, the most accepted functional explanation for colophores – the only part of the body of a spring’s tail that attracts water – was as A way to absorb nutrients. Other uses have been suggested in the twenty-first century: it can be Self-cleaning tool or a way to directs spring tail leap.
Dr. Ortega Jimenez, whose research focuses on how animals move, became interested in a tailspring when he saw them jump near a stream. Whereas it was believed that animals could only orient themselves in a direction and then Flipping wildly in the airWhen the arthropods jumped from the bank into the water and back, Dr. Ortega Jimenez noticed that they appeared to have landed exactly where they began. Doing so requires some kind of control throughout the entire jump.
Back in the lab, Dr. Ortega Jimenez began filming Springtails in flight, and designed a small wind tunnel to see how the animals handle different weather conditions. He found that the spring tail colophore was involved in all parts of the jump.
During takeoff, when the springs’ tail hit a tail-like fracula from the water, the colophores picked up a drop of water. When the animals were spinning in the air, they would bend their bodies in a U-shape, which slowed their spin and eventually allowed them to fly straight through the air, like little superheroes.
When flipped upside down while in a wind tunnel, the tail springs with water droplets on their casing were able to flip themselves in less than 20 milliseconds, faster than any animal previously recorded. The chests came out, the pulsating tail descended, and the water colophore gave it a firmer base and a sticky adhesion to the surface.
“They were skydiving, and they were landing on their feet,” said Dr. Ortega Jimenez.
Using mathematical models, the researchers found that the tail springs that had water droplets on their casings fluctuated much less when they landed than the dry springs’ tail. They can end up on their feet in half the time. Although colophores likely have other functions, its role in jumping — during take-off, flight and landing — appears crucial, said Saad Bahla, a biomechanics researcher at Georgia Institute of Technology who also worked on the research. “That, to me, is the cool feature here,” he said.
Dr. Bhamla helped bring in robotics, who designed a spring-based tail robot that can correct itself in the air and land on its feet 75 percent of the time. He said that this type of control has not been well studied in robotics, which often focus on takeoff. Building a machine that can land constantly on its feet means building a machine that can be ready to leap sooner. Because if they can control the jump, they can keep doing it over and over again,” said Dr. Bhamla. “That’s more interesting.”
Dr. Ortega Jimenez said this could also provide an evolutionary explanation for spring tail hops. While there is a lot of speculation at this point and “the evolution of these jumping beasts is a mystery,” the quick recovery from the jump allows the springer to better escape predators. “Preparation is essential for survival,” said Dr. Ortega Jimenez.
The researchers were surprised to find so much control in such small animals. But the dynamics on small scales are often counter-intuitive, and even basic features are easily overlooked. A little water on the stomach can change everything.
“Design wise, it is very simple,” said Dr. Bhamla. “He’s like, ‘Why didn’t I think of this?'” “
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