News / Science & Technology

Exhibit Puts Friendly Face on Spiders

Trapdoor spiders spend most of their time in underground burrows, emerging mainly to grab prey. Their rear half is segmented, a trait visible in some of the earliest spider fossils. (© AMNH\R. Mickens)
Trapdoor spiders spend most of their time in underground burrows, emerging mainly to grab prey. Their rear half is segmented, a trait visible in some of the earliest spider fossils. (© AMNH\R. Mickens)
Adam Phillips
Spiders, a unique class of creatures known as arachnids, come in 43,000 varieties and have thrived for nearly 300 million years on every continent except Antarctica.

Despite their ubiquity - and our frequent contact with them in our homes, gardens and farms - spiders are poorly understood and not well appreciated. A new exhibit at the American Museum of Natural History in New York is out to change that.
 
The museum boasts the world’s largest spider collection, and has populated its new “Spiders Alive!” exhibit with a diverse sampling. Live specimens of 20 different species crawl about in the exhibition’s glass display case, from the tarantula, which can grow to the size of a dinner plate, to the goliath birdeater, and the infamous Black Widow with its distinctive hourglass markings.

Many people think spiders are insects but, unlike insects, spiders have no wings or antennae. Their exoskeletons come in two parts, not three, and they periodically molt those protective shells for new ones. Like other arachnids, such as scorpions and ticks, spiders have eight legs, not six.  

Exhibition curator Norman Platnick says a spider can even lose a leg and live. “And in fact if happens young enough when the spider still has several molts before it becomes an adult, it can even regrow that leg. So clearly, if you can lose them, then having more is an advantage.”

  • Charlotte’s Web author E.B. White consulted with a museum curator while writing the classic children’s book. She named the main character Charlotte A. Cavatica after a common orb weaver, Araneus cavaticus.
    (© AMNH\R. Mickens)
  • Ornamental tarantulas can be as colorful as tropical birds, a sharp contrast to the fearsome, dark and dangerous creatures many imagine. (© AMNH\R. Mickens)
  • This active hunter searches for food on foot, aided by sharp vision and its ability to sense vibrations—like those of the beating wing on an insect or the patter of steps on the soil. (© AMNH\R. Mickens)
  • One of the few species harmful to people in North America, a black widow often features a red hourglass shape on its underside. (© AMNH\R. Mickens)
  • This is a rare 100-million-year-old spider fossil in limestone. Spiders do not preserve well in sediment because they have a relatively soft “shell.”  (© AMNH\D. Grimaldi)
  • One of the biggest spiders in the world, the Goliath bird eater preys on snakes, mice, and frogs but, despite the name, rarely birds. (© AMNH\R. Mickens)
  • This stunning tarantula, which lives mainly on the Pacific coast of Mexico, resides in burrows, hurrying out to prey on insects, small frogs, lizards, and mice. (© AMNH\R. Mickens)
  • Trapdoor spiders spend most of their time in underground burrows, emerging mainly to grab prey. Their rear half is segmented, a trait visible in some of the earliest spider fossils. (© AMNH\R. Mickens)
  • This spider was trapped in tree resin about 20 million years ago. Over time the resin fossilized into amber, preserving the animal inside. (© AMNH\D. Grimaldi)


If bugs give you the creeps, you might want to consider that if it weren’t for spiders, we'd all be neck-deep in insects. On just a single hectare of land, a normal population of spiders can devour as much as 80 kilograms of bugs each year, according to Platnick.

“If the spiders were not here, we might not be here either because insects would have devoured all those crops,” he says.

Spiders’ methods for hunting and eating their prey are both strange and ingenious. While humans begin to digest food once it's inside the mouth, most spiders pierce their prey with specialized fangs, then inject them with a paralyzing venom. Next, they regurgitate digestive fluid into their victim’s bodies, essentially liquefying them in their shells.   

“And then the spider sucks up the liquid like a milk shake,” says Hazel Davies, the museum’s curator of living exhibits.

Few spiders have venom that can hurt a person. In fact, some spider venoms may be beneficial to human health.

“Some spider venoms, or some component of the venoms of some species of spiders, seem to be able to inhibit the transmission of certain nerve impulses across synapses,"  says Platnick. "So people are looking at those kinds of venoms as potential cures for certain kinds of neurological diseases, like epilepsy, that involve those kinds of transmissions.”   
 
Only about half of the world’s 43,000 spider species spin webs.   

“The other half are hunting spiders. They actively hunt down their prey," says Platnick. "Or they may be fairly sedentary like crab spiders and tarantulas and wait for the prey to come near them.”

Spiders who spin webs must also wait for an insect to become ensnared. Depending on the species, webs can be beautifully symmetrical or a seemingly random jumble. Either way, Platnick says the silk itself has wondrous properties. For example, some silks have a tensile strength far greater than a comparable strand of steel.  

“If we could develop man-made equivalents of spider silk, we could revolutionize everything from parachutes to bulletproof vests,” he says.    

Because spider silks contain a vast inventory of potentially useful proteins, Platnick advocates that spiders’ natural habitats be protected from human incursions, such as logging. He leads a National Science Foundation-funded initiative called the Planetary Biodiversity Inventory, a project that has engaged more than 45 arachnid experts in 12 countries.

“Any time enough habitat gets destroyed that we lose a species, we may be losing something extremely valuable too," he says, "and, in many cases, that means we lose it even before we knew it existed.”
     
The “Spiders Alive!” exhibition will be on display at the American Museum of Natural History in New York City until early December 2012.

You May Like

Polls Open in Scotland Independence Vote

As race to persuade undecided voters continues, 'No' voters say they believe life in Scotland will slowly improve, 'Yes' vote not worth the risk More

China to Invest $20 billion In India Amid Border Dispute

Border spat between armies of two countries in Himalayas underlines mutual tensions despite growing commercial ties highlighted by Xi Jinping's high profile visit More

Ukrainian Activist in Despair About Future of Her Country

IrIna Dovgan, accused of being a spy and tortured by pro-Russian separatists, is appealing to UN Human Rights Council to support her country More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
A Dinosaur Fit for Land and Wateri
X
September 17, 2014 8:44 PM
Residents and tourists in Washington D.C. can now examine a life-size replica of an unusual dinosaur that lived almost a hundred million years ago in northern Africa. Scientists say studying the behemoth named Spinosaurus helps them better understand how some prehistoric animals adapted to life on land and in water. The Spinosaurus replica is on display at the National Geographic museum. VOA’s George Putic has more.
Video

Video A Dinosaur Fit for Land and Water

Residents and tourists in Washington D.C. can now examine a life-size replica of an unusual dinosaur that lived almost a hundred million years ago in northern Africa. Scientists say studying the behemoth named Spinosaurus helps them better understand how some prehistoric animals adapted to life on land and in water. The Spinosaurus replica is on display at the National Geographic museum. VOA’s George Putic has more.
Video

Video Iraqi Kurdistan Church Helps Christian Children Cope find shelter in churches in the Kurdish capital, Irbil

In the past six weeks, tens of thousands of Iraqi Christians have been forced to flee their homes by Islamic State militants and find shelter in churches in the Kurdish capital, Irbil. Despite U.S. airstrikes in the region, the prospect of people returning home is still very low and concerns are starting to grow over the impact this is having on the displaced youth. Sebastian Meyer reports from Irbil on how one church is coping.
Video

Video NASA Picks Boeing, SpaceX to Carry Astronauts Into Space

The U.S. space agency, NASA, has chosen Boeing and SpaceX companies to build the next generation of spacecraft that will carry U.S. astronauts to the International Space Station by the year 2017. The deal with private industry enables NASA to end its dependence on Russia to send space crews into low Earth orbit and back. Zlatica Hoke has more.
Video

Video Future of Ukrainian Former President's Estate Uncertain

More than six months after Ukraine's former President Viktor Yanukovych fled revolution to Russia, authorities have yet to gain control of his palatial estate. Protesters occupy the grounds and opened it to tourists but they are also refusing to turn it over to the state. VOA's Daniel Schearf reports from Mezhigirya, just north of Kyiv.
Video

Video China Muslims Work to Change Perceptions After Knife Attacks

China says its has sentenced three men to death and one woman to life in prison for a deadly knife attack in March that left more than 30 dead and 140 injured. Beijing says Muslim militants from China's restive western region of Xinjiang carried out the attacks. Now, more than six months after the incident, residents in the city are still coping with the aftermath. VOA's Bill Ide has more from Kunming.
Video

Video Enviropreneur Seeks to Save the Environment, Empower the Community

Lorna Rutto, a former banker, is now an ‘enviropreneur’ - turning plastic waste into furniture and fences discusses the challenges she faces in Africa with raw materials and the environment.
Video

Video West Trades Accusations Over Ransoms

As world leaders try to forge a common response to the threat posed by Islamic State militants in Iraq and Syria, there is simmering tension over differing policies on paying ransoms. In the past month, the jihadist group has beheaded two Americans and one Briton. Both countries refuse to pay ransom money. As Henry Ridgwell reports for VOA from London, there is uncertainty in the approach of some other European nations.
Video

Video Scotland Independence Bid Stokes Global Interest

The people of Scotland are preparing to vote on whether to become independent and break away from the rest of Britain, in a referendum being watched carefully in many other countries. Some see it as a risky experiment; while others hope a successful vote for independence might energize their own separatist demands. Foreign immigrants to Scotland have a front row seat for the vote. VOA’s Henry Ridgwell spoke to some of them in Edinburgh.


Carnage and mayhem are part of daily life in northern Nigeria, the result of a terror campaign by the Islamist group Boko Haram. Fears are growing that Nigeria’s government may not know how to counter it, and may be making things worse. More

AppleAndroid