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

Reports of Mass Murder on Mediterranean Smuggler’s Boat

Boat sailed from Libya with 750 migrants aboard and arrived in Italy with 569 More

Video New Thailand Hotline Targets Misbehaving Monks

Officials say move aims to restore country’s image of Buddhism, tarnished by recent high profile scandals such as opulent lifestyle, drug and alcohol abuse, as well as child sex abuse More

Study: Dust from Sahara Helped Form Bahama Islands

What does the Sahara have in common with a Caribbean island? Quite a lot, researchers say 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.
Astronauts Train in Underwater Labi
X
George Putic
July 25, 2014 7:25 PM
In the world’s only underwater laboratory, four U.S. astronauts train for a planned visit to an asteroid. The lab - called Aquarius- is located five kilometers off Key Largo, in southern Florida. Living in close quarters and making excursions only into the surrounding ocean, they try to simulate the daily routine of a crew that will someday travel to collect samples of a rock orbiting far away from earth. VOA’s George Putic has more.
Video

Video Astronauts Train in Underwater Lab

In the world’s only underwater laboratory, four U.S. astronauts train for a planned visit to an asteroid. The lab - called Aquarius- is located five kilometers off Key Largo, in southern Florida. Living in close quarters and making excursions only into the surrounding ocean, they try to simulate the daily routine of a crew that will someday travel to collect samples of a rock orbiting far away from earth. VOA’s George Putic has more.
Video

Video Not Even Monks Spared From Thailand’s Junta-Backed Morality Push

With Thailand’s military government firmly in control after May’s bloodless coup, authorities are carrying out plans they say are aimed at restoring discipline, morality and patriotism to all Thais. The measures include a crackdown on illegal gambling, education reforms to promote students’ moral development, and a new 24-hour phone hotline for citizens to report misbehaving monks. Steve Sandford reports from Bangkok.
Video

Video Virtual Program Teaches Farming Skills

In a fast-changing world beset by unpredictable climate conditions, farmers cannot afford to ignore new technology. Researchers in Australia are developing an online virtual world program to share information about climate change and more sustainable farming techniques for sugar cane growers. As VOA's Zlatica Hoke reports, the idea is to create a wider support network for farmers.
Video

Video Airline Expert: Missile will Show Signature on Debris

The debris field from Malaysia Airlines Flight 17 is spread over a 21-kilometer radius in eastern Ukraine. It is expected to take investigators months to sort through the airplane pieces to learn about the missile that brought down the jetliner and who fired it. VOAs Carolyn Presutti explains how this work will be done.
Video

Video Treatment for Childhood Epilepsy Heats up Medical Marijuana Debate

In the United States, marijuana is classed as an illegal drug by the federal government. But nearly half the states have legalized it, to some degree. Proponents say some strains of marijuana might have exceptional health benefits, for treating pain or inflammation in chronic conditions such as cancer, multiple sclerosis and epilepsy. Shelley Schlender reports on a strain of medical marijuana developed in Colorado that is reputed to reduce seizures in childhood epilepsy
Video

Video Airbus Adds Metal 3D Printed Parts to New Jets

By the end of this year, European aircraft manufacturing consortium Airbus plans to deliver the first of its new, extra-wide-body passenger jets, the A350-XWB. Among other technological innovations, the new plane will also incorporate metal parts made in a 3-D printer. VOA's George Putic has more.
Video

Video AIDS Conference Welcomes Exciting Developments in HIV Treatment, Prevention

Significant strides have been made in recent years toward the treatment and prevention of HIV, the virus that causes AIDS. This year, at the International AIDS Conference, the AIDS community welcomed progress on a new pill that may prevent transmission of the deadly virus. VOA’s Anita Powell reports from Melbourne, Australia.
Video

Video IAEA: Iran Turns its Enriched Uranium Into Less Harmful Form

Iran has converted its stockpiles of enriched uranium into a less dangerous form that is more difficult to use for nuclear weapons, according to the United Nations’ Atomic Energy Agency. The move complies with an interim deal reached with Western powers on Iran's nuclear program last year, in exchange for easing of sanctions. Henry Ridgwell reports for VOA from London.

AppleAndroid