奇速英语

研究发现，蜘蛛也有听觉

Scientists have known spiders have exceptional vision, particularly jumping spiders. They’ve even known spiders can feel nearby vibrations. However, because they don’t have ears, scientists believed they couldn’t hear at all.

“The standard textbooks say spiders are especially sensitive to airborne vibrations from nearby sources. We’ve discovered jumping spiders can hear things from much farther away than this,” says Gil Menda, co-researcher of Cornell University.

The researchers were studying how spiders process visual information by making neural recordings of their brain activity. After taking a recording, Gil Menda moved his chair and it squeaked(吱吱叫). “The way we do neural(神经系统的) recordings,” explains Paul Shamble, co-researcher, “we set up a speaker so that you can hear when neurons(神经元) fire, they make this really distinct ‘pop’ sound, and when Gil’s chair squeaked, the neuron we were recording from started popping.”

Gil moved his chair again and the neuron popped again. Not convinced of what they were seeing, the two researchers started clapping. When the spider neurons responded, the researchers started moving farther away. They reached 5 meters away from the spider and the reaction continued. The two were amazed. “You thought they were just these little creatures of vibration and vision,” says Paul Shamble, “and now suddenly you realize they can hear, too.”

If spiders don’t have ears, how do spiders hear? It turns out that the hairs on their legs are sensitive to sound. Previously, scientists believed these hairs were only able to detect airborne vibrations. This new discovery has shown that spiders aren’t simply sensing vibrations, but rather hearing. To test this, the researchers placed water on the spider’s legs to muffle(抑制) the vibrations. The spider stopped firing auditory neurons, meaning the spider could no longer hear.

This research only involved jumping spiders, but follow-up studies show many other kinds of spiders are able to hear. Why does all of this matter? This finding could result in new technologies for people.