Placeholder Image

字幕列表 影片播放

  • we've all chased lightning bugs as kids, but what's going on behind those glowing

  • behinds?

  • Hey Everyone Julia here for DNews

  • I grew up in the midwest and spent my childhood summers chasing around lightening bugs.

  • There's something about them that just captures the imagination.

  • But such powers of light don't belong to just those bugs.

  • Bioluminescence is found in a lot of different animals! imagine waves of a bright lights

  • trailing behind your ships.

  • Such a phenomenon was part of sailors stories for centuries.

  • It's even described in Jules Verne “20,000 Leagues Under the Seaas a “milky sea”.

  • But it's not just a story or a mystery, really it's all just chemistry.

  • Most of the time it's just two chemicals in particular: luciferin and luciferase.

  • Luciferase, is an enzyme which binds oxygen and luciferin together.

  • This reaction creates a lot of energy, and rather than being released as heat, it gives

  • off light.

  • The color depends on the way the luciferin molecules are arranged.

  • While some organisms produce luciferin, others have to eat the things that produce the chemical.

  • Or in the case of the angler fish, they house the bacteria that makes the chemical.

  • When you think of glowing creatures you might think of only lightning bugs or deep sea creatures.

  • But bioluminescence is surprisingly common.

  • It happens anytime time of day or depth of the ocean.

  • So why do they do it?

  • Well it's not for generating heat.

  • Bioluminescence is a "cold light."

  • Cold light means less than 20% of the light generates thermal radiation, or heat.

  • Some creatures like the anglerfish use this trick as bait to lure in prey, other species

  • use it as a warning, the glow worm signals “I'm poisonous!”, or some species of

  • fish release a flash of bioluminescent goo to confuse their attackers.

  • The hatchet fish uses it for camouflage.

  • Their undersides are lined with photophores, organs filled with those glowing chemicals.

  • This tricks any predators that might attack from below.

  • Normally a fish's silhouette against the sky gives it away, but these photophores make

  • the hatchet fish blend in.

  • Pretty cool right?

  • And a lot of other animals use bioluminescence for communication, Some scientists even think

  • it could be the most common form of communication on the planet!

  • You might be familiar with this kind of light display from lightning bugs signaling to find

  • a mate.

  • Some organisms shine when startled or scared.

  • The Milky Seas in 20,000 leagues was really a bloom of algae, like the dinoflagellate,

  • Noctiluca Scintillans.

  • When these tiny guys get disturbed by a boat or cresting wave, it triggers the chemical

  • reaction.

  • And they light up the sea.

  • Such dinoflagellates are currently putting on quite a show off the coast of Tasmania.

  • But this is different from fluorescence.

  • Fluorescence is when an animal has proteins that reflect light.

  • Kind of like how certain things glow under a blacklight, some animals only glow under

  • certain wavelengths.

  • Like the elegant jelly which reflects blue light.

  • Scientists genetically modified some animals like rabbits and cats with these fluorescent

  • proteins from jellyfish.

  • Yes glowing cats exist.

  • In fact the development of this technique won a Nobel Prize in 2008.

  • By creating glowing cats or sheep, researchers can track the formation of certain biological

  • processes like nerves growing or diseases spreading.

  • Other researchers in San Francisco are creating glowing plants and trees that could light

  • up the night without using power.

  • To find out how check out this video right here!

  • What's your favorite light up animal?

  • I'm kind of obsessed with hankler..

  • I mean angler fish.. let us know down the comments below

we've all chased lightning bugs as kids, but what's going on behind those glowing

字幕與單字

單字即點即查 點擊單字可以查詢單字解釋

B1 中級 美國腔

動物發光(What Makes Some Animals Glow?)

  • 87 2
    joey joey 發佈於 2021 年 04 月 13 日
影片單字