The mysterious tentacled snake

Conspirator
User avatar
Posts: 2485
Joined: Wed Jun 11, 2008 6:10 am

PostThu Feb 04, 2010 2:52 pm » by bugmenot


Tentacled Snake Uses Odd Appendages to Sense Prey :ohno: http://news.nationalgeographic.com/news ... es-snakes/


Image
The mysterious tentacled snake uses its head appendages to hunt fish, a new study says. Photograph courtesy Kenneth Catania

Snakey sense ... tingling!

Just as Spider-man has his spidey sense to warn him when danger's near, the bizarre tentacled snake has its own special system for sensing an approaching meal, a new study says.

The reptile uses its two head tentacles to "see" and pursue prey in murky lakes and slow-moving rivers in Southeast Asia, researchers have discovered. (See snake pictures.)

"When I first saw these things in ... [a] zoo I thought, What the heck? They were an irresistible mystery," said study leader Ken Catania, a biologist at Vanderbilt University in Tennessee.

Video: Tentacled Snake Tricks Fish


Upload to Disclose.tv



Catania and colleagues observed that the tentacled snake hunts in a strange way: It forms a J with its body, slightly moving its lower midsection when fish swim by. This movement usually causes a fish to dart in the opposite direction, straight toward the snake's mouth.

Even after figuring out the snake's technique, the scientists were left wondering what the tentacles were for.

"We suspected they were fish detectors, as the snake is unusual in specializing almost completely on fish as prey," he said.

Night "Vision"

To solve the mystery, Catania and colleagues first marked tentacle nerve fibers of dead snakes with fluorescent dye and viewed them under a microscope. The team found that many nerves crossed the centers of the tentacles rather than at their surfaces.

That finding was intriguing: Nerve cells associated with senses such as taste and touch are not usually so deeply embedded. The structure suggested that these nerve cells were positioned to sense movement of the entire tentacle rather than detailed surface sensations, the study says.

In another experiment using live snakes, the team stroked the appendages with tiny hairs while simultaneously monitoring electrical activity in the snakes' brains.

They also found that the tentacles sensed even the smallest movements of water generated by a nearby vibrating sphere, suggesting the tentacles would also respond to similar movements made by nearby fish.

Following the nerve signals, the team noticed that touch signals from the tentacles ran to a part of the brain that registers vision, meaning that the two senses—touch and vision—work closely together in the tentacles.

Special Snake Sense

As a final test, Catania put fish in the tank with the snakes, turned off the lights in the laboratory, and monitored the snakes—which have perfectly good eyesight—with infrared cameras. The predators caught fish in total darkness with no trouble.

“It may seem a bit odd to have both good eyesight and this special tentacle sense, but really, it isn’t that rare to have predators with two very good senses," Catania said.

"Just look at barn owls—they have great sight and great hearing that they use differently based upon lighting conditions," he said. "The snakes seem to be similar, with their tentacles probably being the greatest help at night."

The research appeared February 1 in The Journal of Experimental Biology.

http://news.nationalgeographic.com/news ... es-snakes/ :look:

Conspirator
User avatar
Posts: 2142
Joined: Sat Jan 16, 2010 2:55 pm
Location: GERMANY

PostFri Feb 05, 2010 4:09 pm » by Germanpils


wow !

smartness combined with real high speed, thats really fascinating
You know, you don't see with your eyes,
you see with your brain and the more
words your brain has, the more things you can see.
(KRS-ONE)

Master Conspirator
User avatar
Posts: 10110
Joined: Wed Jul 01, 2009 10:10 pm
Location: Packing my stuff and moving to Denver like you should be doing

PostFri Feb 05, 2010 7:07 pm » by Savwafair2012


Image

very cool :wink:
Image
FAIR USE NOTICE.
Section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, . http://www.law.cornell.edu/uscode/17/107.shtml



  • Related topics
    Replies
    Views
    Last post
Visit Disclose.tv on Facebook