Happy Nice Mall

After dark, the Watagan Mountains in New South Wales, Australia, can appear from another world to anyone with a headlight. But things took a strange turn in 2015 when John Gould, a behavioral ecologist at Newcastle University in Australia, studied sandpaper frogs in the short-lived ponds of forests for his thesis.

Dr. While Gould was crouching over a pond, searching for a frog, he saw a pea-sized insect that he thought had fallen into the water. On a closer look, Dr. Gould realized that he was not watching a right-side up insect trying to escape from the water, but an upside-down insect that was in full control of its life and current situation. Kneeling under Dr. Gould glided across the bottom surface of the water as if in a parallel world.

The surface of the pool was immaculately motionless, with no apparent wind gusts, and Dr. Gould pulled out his phone to record the water scavenger’s indifferent ceiling wandering. Because the images were irrelevant to his research, Dr. Gould kept the video of the beetle in his files and didn’t get back to him for several years as he finished his PhD. Finally, in June, a wildlife ecologist at the German Center for Integrative Biodiversity Research in Leipzig, Dr. Gould and Jose Valdez have published the first detailed documentation of this behavior in insects in the journal. ethology.

Martin Fikáček of Taiwan’s National Sun Yat-sen University was not involved in the initial research, but identified the beetle as an aquatic scavenger beetle, possibly in the family Hydrophilidae.

While the paper represents the first time the insect’s upside-down underwater scanning has been recorded in the literature, the behavior has been reported before, according to Manu Prakash, a bioengineer at Stanford University who was not involved in the research. Dr. “This is a nice observation,” Prakash wrote in an email.

The movements of the water sweeper differ from the traditional way of walking on water. Sea and water rowers row on the surface of the water with paddle-like legs. With the help of surface tension, some lizards They can run in water by waving their bodies and hitting the surface of the water with their legs.

Under the water, some creatures live an upside-down life. Many are snails. in the ocean, violet snail It sticks upside down to the ocean’s surface with a sticky bubble raft that keeps its crustacean body above the water. The freshwater snail Sorbeoconcha physidae also relies on mucus and scrambles together, wrinkling its feet toward the surface of the water. Dr. “They use a different mechanism because they don’t have legs,” Valdez said of the snails.

In fresh water, some insects are called back swimmers swims upside down, paddling its hairy hind legs under water. The larvae of the water fly Dixidae, also called meniscus midges, use the hairy structures on their abdomens to cling to the water surface upside down.

However, these aquatic scavengers do not swim like dorsal swimmers or larvae. They walk, just as you can imagine a terrestrial insect walking on land or hopping on your ceiling.

First question: How?

“A bit of a question mark,” admitted Dr. Gould, however, himself and Dr. Valdez has some hypotheses.

One possibility, the researchers say, is an air bubble sticking to the belly-up insect, which could provide upward buoyancy keeping the insect aloft. The researchers suggest that even though a bubble this close to the surface might seem to burst, the insect’s bubble was steadfastly full, which somehow prevented the insect from escaping air. Insects that can walk underwater (from right to top) catching air bubbles between your feet.

Second question: Why??

Although the beetle’s feet seemed to pierce the water with every step, its low-profile wander produced no ripples. The researchers suggest that this course of action could help the insect avoid being eaten by anything lurking nearby. Dr. “Any predator above the surface could be looking down and seeing a bubble instead of a tasty treat,” Valdez wrote in an email.

Moving with the drag, buoyancy and viscosity of water often requires more energy than moving on land. However, the authors say the insect can move around quite easily and even appears to be upside down, suggesting that this behavior is not energetically compulsive.

But the only way to know for sure about any of these would be to take the insect species to a lab for further research.

Now, Dr. Gould studies another frog on Kooragang Island, which breeds in artificial wetland pools around the island’s coal ports, not far from the Watagans. Nature there is less unspoilt but still holds little wonders; Recently, Dr. Gould saw a slug gracefully spinning from the top of a fence to the ground like an aerial artist, using a rope of its own mucus as a climbing rope.

But what about this particular insect? Water scavengers have a short lifespan, so this particular insect is most likely gone, returning its body to the petrichor-scented soil of the Watagans. But other insects stay, live and die, and walk on any surface that will catch them.