Unit9SYMBIOSIS共生现象

1、Unit 9SYMBIOSIS共生现象Sandy FritzIN THE WILD, SOME ANIMALS HAVE DEVELOPED PARTNERSHIPS TO HELP IN THESTRUGGLE FOR SURVAL在野外 , 一些动物形成了伙伴关系，有助于为了生存而斗争The owl hunts alone at night. In the dark, it listens carefully for the sounds of scurrying mice orthe ruffling of small birds. With wings that are nearly

2、soundless, the owl glides and stops, again andagain, searching for food.猫头鹰夜里独自打猎。在黑暗中， 猫头鹰仔细倾听迅速跑动的老鼠或受惊的小鸟发出的声音。猫头鹰用几乎无声的翅膀滑行和停止脚步, 一次又一次 , 寻找食物。In the warm spring morning, a blooming treeabsorbs the suns rays. A strong wind stirs theleaves and suddenly one of the leaves begins to fly! The leaf is

3、 really no leaf at allits an insectdisguised as a leaf.在温暖的春天的早晨, 盛开的树木吸收着太阳光线。大风吹着树叶，突然一片树叶开始飞起来! 那只是装扮成树叶的一只昆虫而已。Each animal has its own way of surviving in the wild. Some creatures find safety in numbersand travel in flocks, schools, or herds. Other animals hunt and live alone, banding-up only wh

4、enmating time grows near. But all animalsconfrontthe same challenge: how to collect food, findshelter , and avoid other animals that would eat them. Each species (kind of creature) hasdifferent strategies for surviving in the environment that it calls每一种动物都具有在野外“ home” .生存的方法。有些动物觉得与数量纵多的动物待在一起时便有了安

5、全感，他们一群一群到处迁移。有些动物则独自狩猎、独自生活，只有临近交配季节才聚集到一起。但是所有的动物都面临同样的挑战: 如何收集食物 , 找到住所 , 并避免其他可能会吃它们的动物。每一个物种( 一种生物 ) 在环境中生存有不同的策略, （这个环境）称为“家”。HELPING EACH OTHER互相帮助Among the most interesting survival strategies animals and plants have developed is a1relationship calledsymbiosis(SIM-bye-OH-sis). 其中动物和植物已经形成的最有

6、趣的生存策略是一种关系称为共生( 共生现象 ) 。 In a symbiotic relationship, animals and plants of differentspecies live together and help each othersurvive . As a team, both benefit. And as a team, the pairsurvives and even thrives in places where the two alone might have failed.在一个共生关系里,动物和植物的不同的物种们生活在一起, 互相帮助生存。作为一个团队

7、, 共同受益。作为一个团队 , 两个物种共同生存, 甚至能在两个物种单独时可能会失败的地方繁荣。The tropicalrainforest of South America supports the greatest animal and plantdiversity(variety) in the world.在美国南部的热带雨林地区具有世界上最全的动植物种类。Its notsurprising, then, to find successful symbiotic teamsoperatingthere. , 然后找到成功的共生团队运作在那里，这并不令人惊奇。One of the mos

8、t successful and clearly visible symbioticrelationships is the one that exists between a tree calledbullhorn acacia(ah-KAY-sha)and a group ofants that make the tree their home.其中体现了最为成功并且清晰可见的共生关系之一是一种叫牛角刺槐和把此树当作家园的蚂蚁之间的关系。The bullhorn acacia is not a tree of thedark, windless depths of the tropical

9、 rainforest. 牛角相思树不喜欢在阴暗不透风茂密的热带雨林区中生长。 Instead, it favors broad clearings-places where tall trees have fallen or land has been cleared for roads or homesteads . 相反它喜欢开阔地，即树被砍光、泥土因筑路或修建宅基地而被移平的地方。But in colonizingplaces where the unfiltered sunlightstreams in, the bullhornacacia has serious competit

10、ion. Fast-growing strangler vines, creepers, and seedlingscompete forspace in the newly-opened areas. In this race for the sun, the bullhorn acacia has help. The tree hasbecome a home and a food source for ahorde of aggressive, stinging ants.但是牛角相思树在灌木丛生地有恶性竞争，此地有未过滤的阳光照进来。快速生长的绞杀藤、爬行动物、幼苗，他们在新开辟的地区

11、争夺空间。在这个争夺太阳的比赛中, 牛角相思树有帮助。这棵树已经成为一大群咄咄逼人的带刺的蚂蚁的家和食物来源。ANT AND TREE蚂蚁和树As the bullhorn acacia grows, it produces massive hornlike thorns. Each thorn is about sixinches long. The thorns grow in pairs along the tree trunk. These thorns are soft-centeredperfecthomes for the ants. In one of these thorns

12、, a wandering Pseudomyrmex queen ant will make herhome. Sheambles into the tree, goes straight to the tip of athorn , and bores an opening just under2the tip. After digging out the thorns soft-center, she takes up residence inside and begins layingeggs.随着牛角相思树的生长, 它长出了大量的牛角刺。每个刺约6 英寸长。这些刺成对的沿着树干生长。这

13、些荆棘是蚂蚁的松软中心，完美住所。在其中一个荆棘, 一个可以乱真的蚁后会筑造她的家。她缓慢走进这棵树，直接进入刺的尖端, 在刺的下面挖一个孔，挖掘出刺的松软中心后，她占领里面的空间然后开始产卵。Soon a brood of worker ants arescurryingaround the leaves and branches of the tree,excavating (digging out) other thorns toaccommodatethe ever-growing ant family. The bullhornacacia provides not only a h

14、ome, but also nourishment (food) for the ants; but near the stem of eachleaf tiny white pellets appear. These are sugar-rich Beltian bodies. The Beltian pellets feed the adultants and their developing larvae.很快一群工人蚂蚁争先恐后在树叶和树枝忙碌, 挖掘 ( 挖掘 ) 其他的刺 , 以便于给日益增长的蚂蚁家族提供住所。牛角相思树不仅提供了一个家,而且给了蚂蚁营养( 食品 ), 但是每片叶

15、子附近有小白球出现。这些都是富含糖的贝尔特体。贝尔特颗粒给成年蚂蚁和成长中的幼虫提供了养料。Ants are naturally very protective of their nest. Soldiers constantly patrol the leaves keeping asharp watch forintruders . If an unlucky leaf-eating insect triessnacking on the tree, it suffers thesame fate as if it wandered into an ant nest. Any intrud

16、er, no matter what its size, is attacked by theants.蚂蚁本性上非常保护自己的巢。士兵经常巡逻树叶，他们敏锐地观察入侵者。如果一只不幸的食叶昆虫试图在树上吃食, 它会遭受同样的命运，好比它已经走进了一个蚁巢。任何入侵者, 不论其大小 , 会受到蚂蚁的攻击。Even large animals like goats are“ persuaded” to leave the tree alone when confronted with the stinging bites of the ants.和很会蜇人的蚂蚁遭遇时，甚至像山羊用那样大的动物也

17、会被提醒不要去理会那棵树。As a team, the tree and the antsthrive in one of the most competitive environments on Earth.The partnershipbetween the bullhorn acacia and its ant guest is a type of symbiotic relationshipcalled mutualism . The wordmutual means shared , and both partners share the hazards and thebenefit

18、s of living together.作为一个团队, 树和蚂蚁生长在地球上一个最有竞争力的环境中。牛角相思树和它的蚂蚁客人之间的伙伴关系，是一种共生关系称为互利共生。这个词意味着相互共享, 双方共享住在一起的风险和好处。In the tropical seas, some different kinds of mutualistic relationships exist between certainfishes. Somelong-snoutedfish with tweezer-liketeeth enjoy almost complete safety no matter wher

19、e3they swim. These are cleaner fish, usually identified by their bright colors and markings. With specialdance-like swimming, they communicate their willingness to clean any fish they come in contact with.在热带海洋 , 一些不同种类的有互惠关系物种在某些鱼类间生存。一些长鼻鱼长着像镊子样的牙齿，不论他们游到哪里享受着几乎绝对的安全。这些清洁鱼, 通常可以从他们鲜艳的颜色和标记中识别。尤其是游

20、泳像跳舞的鱼, 他们表达出愿意给与他们接触的任何鱼做清洁。Even largepredatory(hunting) fish wait patiently to begroomed as special cleaningstations as a group of little fish pick parasites (creatures that infest other creatures) clean,nibble thedead flesh from wounds, and even fearlessly enter their hosts mouth to finish their

21、cleaning routine.即使以肉为食的大鱼也得耐着性子等在清洁站，让一群小鱼伺候它，因为这群小鱼可以把寄生物清理干净，慢慢把伤口上的腐肉吃掉，甚至无所畏惧地进入主人的嘴中去完成清洁的差事。At sea, just as on land, different kinds of symbiotic relationships exist. Brightly colored pilotfish gain protection by swimming alongside sharks, and feed by snatching tiny morsels of food fromthe wa

22、ter as the sharkrips open its prey. The sharks arent helped in any way by the pilot fish, yetthey arent harmed by them either. This kind of symbiotic relationship is calledcommensalism. In acommensal relationship, one creaturehangs“around , ” yet only one of the partne rs benefits from therelationsh

23、ip.在海上 , 像在陆地上一样, 不同种类的共生关系存在。色彩鲜艳的领航鱼从鲨鱼身旁游过时可获得保护, 当鲨鱼撕开猎物时（领航鱼）从水中抓取微小的少量的食物来吃。领航鱼不以任何方式帮助鲨鱼, 然而他们也不伤害鲨鱼。这种共生关系称为共生。在一个共生的关系里, 一个生物“徘徊” , 但只有其中一个同伴的利益来自这个关系。Birds, too, form symbiotic relationships with other animals. Cattle egrets, herons that oncelived mostly in Asia and Africa, have made their way to the United States and can be foundperchingon the back of domestic (tame) cattle and horses. These birds also