译言网 | 世界上最大最结实的蜘蛛网

River-Spanning Spider Web

横跨河流两岸的巨大蜘蛛网

Photograph courtesy Matjaz Kuntner

感谢Matjaz Kuntner提供的照片

Ariver-spanning spider web dwarfs a park ranger in Madagascar in 2008.Made of the world's strongest known biological material, the web is theproduct of a new species, the Darwin's bark spider, which makes theworld's largest webs of any single spider, new studies say.

2008年，在马达加斯加岛，一名护林员正在查看一个河流两岸的蜘蛛网。最新研究表明，这个蜘蛛网是用世界上已知的最结实的生物材料编织而成的，它是达尔文吠蛛这一新的蜘蛛种类的产物。这使其成为了当今世界最大的蜘蛛网。

ZoologistIngi Agnarsson and colleagues have found Darwin's bark spider webs aswide as 82 feet (25 meters)—about as long as two city buses.

波多黎各大学的动物学家Ingi Agnarsson和其同事发现了由达尔文吠蛛结出的宽达82英尺（约合25米）的蜘蛛网，这相当于两辆城市大巴的长度

InAndasibe-Mantadia National Park (pictured), "the park rangers knewabout them, and I think they've shown them to tourists for a while,"said Agnarsson, of the University of Puerto Rico.

Agnarsson说，在Andasibe-Mantadia国家公园（图中所示），“护林员已经知道了这种蜘蛛网的存在，我想他们曾经向游客展示过这些蜘蛛网。”

Butthe Darwin's bark spider and its record-breaking webs were unknown toscience until they were documented by the team, whose findings appearthis week in the Journal of Arachnology and PLoS ONE.

但是，在Agnarsson团队发现这些蜘蛛以前科学家对达尔文吠蛛及其破纪录的蛛网一无所知，他们的这一发现将会刊登在这周的《节肢动物学期刊》和《PLoS ONE》杂志上。

  Darwin's Bark Spider Web

An approximately three-foot-wide (meter-wide) Darwin's bark spider web hangs above a river in Madagascar.

这张达尔文吠蛛织成的蛛网大约三尺宽（约一米宽），横跨在马达加斯加岛的一条河上。

Thoughthe new species' webs are overall the world's largest, other spidersmight exist that create larger orbs—the spiral at the center of theweb—according to study co-author Todd Blackledge, a biologist at the University of Akron in Ohio.

Despitespinning webs of Spider-Man-like size and strength, the Darwin's barkspider uses them to feed mainly on small fry—insects such as mayfliesand dragonflies, the team found.

"In our dreams, we were hoping for bats or birds or something," the University of Puerto Rico's Agnarsson joked.

Agnarsson开玩笑地说道，“按照我们的想象，我们希望这些蛛网能够捕捉蝙蝠或是鸟类这种大东西。”

Female Darwin's Bark Spider

雌性达尔文吠蛛

Theweavers of the largest Darwin's bark spider webs are almost alwaysfemale, such as this spider pictured in 2008, said Agnarsson, a granteeof the National Geographic Society's Committee for Research and Exploration. 

Juvenilemales also weave spider webs, but once they become adults, they abandonthis behavior and instead direct their energies solely to sex.

Forsurvival, the Darwin's bark spider relies in part on its mottled,jagged appearance, which camouflages the spider against trees and—alongwith Charles Darwin—inspired its name. The species is known to exist only on the island of Madagascar, off Africa's southeastern coast.

为了生存，达尔文吠蛛依靠其色彩斑斓、粗糙的外表与树完美的融为一体，这充分验证查理斯.罗伯特.达尔文的进化论，达尔文吠蛛也因此得名。已知的达尔文吠蛛仅存在于非洲东南岸的马达加斯加岛。

Giant Web, Snack-Size Fare

大网捕获小飞虫

Dozens of mayflies hang helpless in a Darwin's bark spider's web in 2008.

Darwin's bark spider webs are made out of two basic kinds of silk, Agnarsson explained.

"Dragline"silk is used to create the supporting strands that anchor the endpointsof an orb web to tree branches overhanging rivers or lakes and formsthe radial threads in the web. Stretchier, stickier silk is used tocreate the spiral that captures prey.

“牵引”蛛丝作为支撑股，用来将圆网的一个个终点固定在外悬在河湖之上的树杈上，形成一种辐射状。更具延展性，粘性的蛛丝则被用于织出捕获猎物的螺旋形结构。

Whenan insect flies into the web, it becomes stuck, and its strugglescauses the silk lines to vibrate, alerting the Darwin's bark spider.

The spider then crawls to the captured insect, and envelops it in a silk cocoon to eat at its leisure.

Unlikemost spiders, Darwin's bark spiders will sometimes wrap several insectcorpses into a single cocoon, creating a snack pack for laterconsumption.

不同于大部分的蜘蛛，达尔文吠蛛有时会将多个昆虫尸体过程茧，等到以后享用这一美味。

Towering Achievement                                                                                               

 

杰出的成就

  

Unliketheir webs, Darwin's bark spiders aren't very big: Not counting itslegs, an adult is usually less than 0.8 inch (2 centimeters) long,Agnarsson said.Earlier this year, study team member Matja? Kuntner, ofthe Slovenian Academy of Sciences and Arts, uses a tape measure todetermine how high up the center of a Darwin's bark spider web is.

Agnarsson说，与其结出的巨大蛛网不同，达尔文吠蛛并不是非常大：不算腿部，一只成年达尔文吠蛛的长度通常不到0.8英寸（约两厘米）。

An analysis of the Darwin's bark spider's silk indicates it's the toughest biological material discovered to date.

"'Tough'means the ability to absorb energy before breaking, and results from acombination of strength and elasticity," Agnarsson explained.

TheDarwin’s bark spider's silk "is about the strength of steel but much,much tougher, because it also stretches. It's many times tougher thaneven Kevlar, which is one of the best man-made materials."

Behind the Web

          

蛛网背后的故事

Scientistsin 2010 observe the web of an unnamed species that may be a closerelative of the Darwin's bark spider and also happens to live inMadagascar's Andasibe-Mantadia National Park.

Thecentral orb structure of this spider's web is about three feet (onemeter) wide. By contrast, the orb of a Darwin's bark spider web can beup to nine feet (three meters) across, though most are much smaller.

Darwin's Bark Booby Trap

达尔文吠蛛的陷阱

Oneof the first things Agnarsson's team wondered after learning about theDarwin's bark spider was exactly how it creates webs wide enough to spanbodies of water, such as this river in Madagascar's Andasibe NationalPark, pictured in 2010.

Oneof the rangers "said the spiders do a Tarzan swing, like they hang downon the silk and swing over," Agnarsson said. "We really, really triedto verify that, but it turned out to be false."

Since then, team member Matjaz Gregori? has discovered the spider's trick and will describe it in a future science paper.

Bull's-Eye

像不像靶心

Agnarsson,shown behind a Darwin's bark spider web in 2010, hopes that studies ofthe species will help shed light on mysteries of spider silk.

"Almostall of the spider-silk research has focused on one or two spiderspecies," he said, referring to golden orb weavers and spiders ofthe Agriopegenus. "Our interest is in looking much more broadly acrossthe diversity of spiders.

"There'sno reason to think that the two exemplar species that most researchershappen to be studying are among those that make the best silk of all thespiders."