猪笼草利用雨滴捕获猎物-凯发k8官网

猪笼草利用雨滴捕获猎物
文章来源:未知 文章作者:enread 发布时间:2012-06-18 06:17 字体: [ ] 
(单词翻译:双击或拖选)

during heavy rain, the lid of nepenthes gracilis(股薄肌) 2 acts like a springboard, catapulting insects that seek shelter on its underside directly into the fluid-filled 1, new research has found. the findings were published june 13, in the journal plos one. pitcher plants (nepenthes) rely on insects as a source of 3, enabling them to colonise nutrient-poor habitats where other plants struggle to grow. 4 is captured in specialised pitcher-shaped leaves with slippery(滑的) surfaces on the upper 5 and inner wall, and drowns in the digestive fluid at the bottom. under humid conditions, the wettable pitcher rim is covered by a very thin, continuous film of water. if an insect tries to walk on the wet surface, its 6 pads (the 'soles' of its feet) are prevented from making contact with the surface and instead slip on the water layer, similar to the 'aquaplaning' effect of a car tire on a wet road.

however, researchers have now discovered a new, unique method of capturing insects by the pitcher plant nepenthes gracilis.

the lead author of the paper, dr ulrike bauer from the university of cambridge's department of plant sciences, said: "it all started with the observation of a 7 seeking shelter under a n. gracilis lid during a tropical rainstorm. instead of finding a safe -- and dry -- place to rest, the beetle ended up in the pitcher fluid, captured by the plant. we had observed ants crawling under the lid without difficulty many times before, so we assumed that the rain played a role, maybe causing the lid to vibrate and 'catapulting' the beetle into the trap, similar to the springboard at a swimming pool."

to test their hypothesis, the scientists simulated 'rain' with a hospital drip and recorded its effect on a captive colony of ants that was 8 on the nectar under the lid. they counted the number of ants that fell from the lid in relation to the total number of visitors. they found that ants were safe before and directly after the 'rain', but when the drip was switched on about 40% of the ants got trapped.

further research revealed that the lower lid surface of the n. gracilis pitcher is covered with highly specialised wax crystals. this structure seems to provide just the right level of slipperiness to enable insects to walk on the surface under 'calm' conditions but lose their footing when the lid is disturbed (in most cases, by rain drops). the scientists also found that the lid of n. gracilis 9 larger amounts of attractive nectar than that of other pitcher plants, presumably to take advantage of this unique 10.

dr bauer added: "scientists have tried to 11 the mysteries of these plants since the days of charles darwin. the fact that we keep discovering new trapping 12 in the 21st century makes me curious what other surprises these amazing plants might still have in store!"



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1 s2gz7     
n.(有嘴和柄的)大水罐;(棒球)投手
参考例句:
  • he poured the milk out of the pitcher.他从大罐中倒出牛奶。
  • any pitcher is liable to crack during a tight game.任何投手在紧张的比赛中都可能会失常。
2 d4fd9938d0d20d5c03d355623c59c88d     
大水罐( pitcher的名词复数 )
参考例句:
  • over the next five years, he became one of the greatest pitchers in baseball. 在接下来的5年时间里,他成为了最了不起的棒球投手之一。
  • why he probably won't: pitchers on also-rans can win the award. 为什麽不是他得奖:投手在失败的球队可以赢得赛扬奖。
3 6a1e1ed248a3ac49744c39cc962fb607     
n.(食品或化学品)营养物,营养品( nutrient的名词复数 )
参考例句:
  • a lack of essential nutrients 基本营养的缺乏
  • nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》
4 g1czh     
n.被掠食者,牺牲者,掠食;v.捕食,掠夺,折磨
参考例句:
  • stronger animals prey on weaker ones.弱肉强食。
  • the lion was hunting for its prey.狮子在寻找猎物。
5 rxsxl     
n.(圆物的)边,轮缘;边界
参考例句:
  • the water was even with the rim of the basin.盆里的水与盆边平齐了。
  • she looked at him over the rim of her glass.她的目光越过玻璃杯的边沿看着他。
6 cyvzv     
n.粘合剂;adj.可粘着的,粘性的
参考例句:
  • you'll need a strong adhesive to mend that chair. 你需要一种粘性很强的东西来修理那把椅子。
  • would you give me an adhesive stamp?请给我一枚带胶邮票好吗?
7 qudzv     
n.甲虫,近视眼的人
参考例句:
  • a firefly is a type of beetle.萤火虫是一种甲虫。
  • he saw a shiny green beetle on a leaf.我看见树叶上有一只闪闪发光的绿色甲虫。
8 6101d89c0b474e01becb6651ecd4f87f     
v.搜寻(食物),尤指动物觅(食)( forage的现在分词 );(尤指用手)搜寻(东西)
参考例句:
  • they eke out a precarious existence foraging in rubbish dumps. 他们靠在垃圾场捡垃圾维持着朝不保夕的生活。 来自《简明英汉词典》
  • the campers went foraging for wood to make a fire. 露营者去搜寻柴木点火。 来自辞典例句
9 b951c7cca7237b8e550dc03599b78b6f     
v.(尤指动物或植物器官)分泌( secrete的第三人称单数 );隐匿,隐藏
参考例句:
  • the pineal gland secretes melanin during times of relaxation and visualization. 松果体在放松时分泌黑色素是明白无误的。 来自互联网
  • for example, the archegonium (female organ) of the moss funaria secretes sucrose. 例如藓类颈卵器(雌性器官)分泌蔗糖。 来自互联网
10 zcwxr     
n.机械装置;机构,结构
参考例句:
  • the bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
  • the mechanism of the machine is very complicated.这台机器的结构是非常复杂的。
11 ajzwo     
v.弄清楚(秘密);拆开,解开,松开
参考例句:
  • he was good with his hands and could unravel a knot or untangle yarn that others wouldn't even attempt.他的手很灵巧,其他人甚至都不敢尝试的一些难解的绳结或缠在一起的纱线,他都能解开。
  • this is the attitude that led him to unravel a mystery that long puzzled chinese historians.正是这种态度使他解决了长期以来使中国历史学家们大惑不解的谜。
12 d0db71d70348ef1c49f05f59097917b8     
n.机械( mechanism的名词复数 );机械装置;[生物学] 机制;机械作用
参考例句:
  • the research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。 来自《简明英汉词典》
  • he explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》
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