The alkali fly can dive underwater and can reemerge to the surface without ever getting wet. It can do this because its hair can create a bubble of air that surrounds the body, a new study finds.
The Diving Flies Of Mono Lake
Alkali flies, also known as Ephydra hians, are small hairy insects that live on the shores of Mono Lake in California.
They can dive underwater to snack on algae and can withstand the highly salty and alkaline waters. When they are underwater, they can also breathe and lay their eggs and after that, emerge from the surface of the salty lake as dry as dust.
The question, however, is how are they able to do all of this and yet stay dry? Biologists have been asking this question for a very long time now. Floris van Breugel, a postdoctoral candidate at the University of Washington, has teamed up with researchers in order to uncover the mystery.
Researchers Team Up To Investigate
In order to uncover the mystery of how alkali flies were able to dive underwater without getting wet, researchers tried to build a sensor that could measure forces and used it along with a high-speed videography, scanning electron microscopy, and "manipulations of water chemistry."
van Breugel's study was also funded by the National Geographic Society Committee for Exploration and Research grant.
The Results
Researchers found that the alkali fly can do what it does because it possesses special traits that enable it to overcome Mono Lake's highly alkaline waters. The fly is covered by large amounts of fine hairs that are in turn coated with a special kind of wax.
The hair on its body allows the fly to create a bubble of air around itself. This bubble of air acts as an "external lung" that prevents the fly from getting wet. Researchers say the hair on the fly's body is an example of "evolution in action."
"The flies have evolved to crawl under water so they can feed on the abundant food, alga, that grows there. The lake has no fish because the fish cannot live in the harsh chemicals of the lake. Thus, the flies have no major predators in the lake. Fish are why most insects would be crazy to crawl under water." said van Breugel.
The alkali flies have long fascinated researchers with their remarkable diving capabilities that they even caught the attention of the famous American writer and adventurer, Mark Twain. Twain wrote about the Ephydra hians in his book, Roughing it, back in 1872.
The study was published in the Proceedings of the National Academy of Sciences on Nov. 20.
