字幕表 動画を再生する 英語字幕をプリント This episode of Deep Look is brought to you by CuriosityStream. For over 300 million years, these lethal hunters have ruled the skies. They're the order Odonata. That's dragonflies and damselflies to most of us. Before the dinosaurs even existed, they had a two-foot wingspan, like a small hawk. Today they're more modest in scale, but no less deadly. Take their eyes. Each tiny hexagonal cell picks up light from a different direction, which gives dragonflies an almost-360-degree range of vision. Four wings help them hover, or turn on a dime. That means this hunter rarely misses. The weird thing is Odonata spend most of their lives in a place where these killer piloting skills don't help. This is where their mothers lay their eggs. When they hatch, the babies – called larvae or nymphs – spend months or years underwater. Their wings are still growing, so they aren't any help in scoring a meal … like this tasty mosquito larva. It's a larva-eat-larva world down here. Did you see that? Let's slow it down. The nymph has a killer lip, called a labium. Remind you of this creepy thing? For this skimmer nymph it's shaped like a spork. Only dragonfly and damselfly nymphs have this special lip. This kind of dragonfly nymph, a darner, has an extra surprise. There's a pair of pincers right at the end. It all happens in a fraction of a second. Think of the lip as a knife, fork and plate all rolled into one. When the meal is over, it folds up neatly, ready for the next occasion. These baby skeeters don't stand a chance. And that's good for us. Let's hope it stays this way for a few million more years. This episode is brought to you by CuriosityStream, a subscription streaming service that offers documentaries and non-fiction titles from some of the world's best filmmakers, including exclusive originals. Want to learn more about dragonflies and other insects? CuriosityStream's video series “Insect Dissection” investigates how insects evolved to dominate our world. To get unlimited access and your first two months free, sign up at curiositystream.com/deeplook and use the promo code deeplook during the sign-up process. Hi there. It's Lauren again. If you're curious about the history of dragonflies, check out Eons, the newest science channel to join the PBS Digital Studios network. This week, Eons travels back in time to the age of giant insects. And make sure to visit PBS Infinite Series, a show about the mathematics that underpins everything in this puzzling, yet fascinating, universe. Thanks for watching.
B2 中上級 米 トンボの赤ちゃんの口が悪夢を与える|ディープルック (A Baby Dragonfly's Mouth Will Give You Nightmares | Deep Look) 28 0 LEO に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語