Próximos videos:

A Baby Dragonfly's Mouth Will Give You Nightmares | Deep Look

7 vistas· 03/04/20
user45
user45
0 Suscriptores
0

Dragonflies might rule the skies, but their babies grow up underwater in a larva-eat-larva world. Luckily for them, they have a killer lip that snatches prey, Alien-style, at lightning speed.

SUBSCRIBE to Deep Look! http://goo.gl/8NwXqt

DEEP LOOK: a new ultra-HD (4K) short video series created by KQED San Francisco and presented by PBS Digital Studios. See the unseen at the very edge of our visible world. Get a new perspective on our place in the universe and meet extraordinary new friends. Explore big scientific mysteries by going incredibly small.

* NEW VIDEOS EVERY OTHER TUESDAY! *

If adult dragonflies are known to be precise hunters, capable of turning on a dime and using their almost-360-degree vision to nab mosquitoes and flies in midair, their dragon-looking babies are even more fearsome.

Dragonflies and damselflies lay their eggs in water. After they hatch, their larvae, also known as nymphs, spend months or years underwater growing wings on their backs.

Without those versatile four wings that adults use to chase down prey, nymphs rely on a mouthpart they shoot out. It’s like a long, hinged arm that they keep folded under their head and it’s eerily similar to the snapping tongue-like protuberance the alien shoots out at Ripley in the sci-fi movie Aliens.

A nymph’s eyesight is almost as precise as an adult dragonfly’s and when they spot something they want to eat, they extrude this mouthpart, called a labium, to engulf, grab, or impale their next meal and draw it back to their mouth. Only dragonfly and damselfly nymphs have this special mouthpart.

“It’s like a built-in spear gun,” said Kathy Biggs, the author of guides to the dragonflies of California and the greater Southwest.

With their labium, nymphs can catch mosquito larvae, worms and even small fish and tadpoles.

“It’s obviously an adaptation to be a predator underwater, where it’s not easy to trap things,” said Dennis Paulson, a dragonfly biologist retired from the University of Puget Sound.

Also known among biologists as a “killer lip,” the labium comes in two versions. There’s the spork-shaped labium that scoops up prey, and a flat one with a pair of pincers on the end that can grab or impale aquatic insects.

-- How many years have dragonflies been around?

Dragonflies have been around for 320 million years, said Ed Jarzembowski, who studies fossil dragonflies at the Nanjing Institute of Geology and Paleontology. That means they were here before the dinosaurs.

-- How big did dragonflies used to be?

Prehistoric dragonflies had a wingspan of 0.7 meters (almost 28 inches). That’s the wingspan of a small hawk today.

---+ Read the entire article on KQED Science:

https://ww2.kqed.org/science/2....017/09/12/a-baby-dra

---+ For more information:

This web site, run by Kathy and David Biggs, has photos and descriptions of California dragonflies and damselflies and information on building a pond to attract the insects to your backyard: http://bigsnest.members.sonic.net/Pond/dragons/

The book "A Dazzle of Dragonflies," by Forrest Mitchell and James Lasswell, has good information on dragonfly nymphs.

---+ More great Deep Look episodes:

Why Is The Very Hungry Caterpillar So Dang Hungry?
https://www.youtube.com/watch?v=el_lPd2oFV4

This Mushroom Starts Killing You Before You Even Realize It
https://www.youtube.com/watch?v=bl9aCH2QaQY&t=57s

Daddy Longlegs Risk Life ... and Especially Limb ... to Survive
https://www.youtube.com/watch?v=tjDmH8zhp6o

This Is Why Water Striders Make Terrible Lifeguards
https://www.youtube.com/watch?v=E2unnSK7WTE

---+ See some great videos and documentaries from PBS Digital Studios!

PBS Eons: The Biggest Thing That Ever Flew
https://www.youtube.com/watch?v=scAp-fncp64

PBS Infinite Series: A Breakthrough in Higher Dimensional Spheres
https://www.youtube.com/watch?v=ciM6wigZK0w

---+ Follow KQED Science:

KQED Science: http://www.kqed.org/science
Tumblr: http://kqedscience.tumblr.com
Twitter: https://www.twitter.com/kqedscience

---+ About KQED

KQED, an NPR and PBS affiliate based in San Francisco, serves the people of Northern California and beyond with a public-supported alternative to commercial media. Home to one of the most listened-to public radio stations in the nation, one of the highest-rated public television services and an award-winning education program, KQED is also a leader and innovator in interactive media and technology, taking people of all ages on journeys of exploration – exposing them to new people, places and ideas.

Funding for Deep Look is provided in part by PBS Digital Studios and the John S. and James L. Knight Foundation. Deep Look is a project of KQED Science, which is supported by HopeLab, The David B. Gold Foundation; S. D. Bechtel, Jr. Foundation; The Dirk and Charlene Kabcenell Foundation; The Vadasz Family Foundation; Smart Family Foundation and the members of KQED.
#deeplook #dragonflies #dragonflynymph

Mostrar más
Comentarios de Facebook

Próximos videos: