第八集：深海生物海洋是世上最大的栖地The ocean. The largest habitat on Earth,对陆地动物来说却是无法居住之处and an inhospitable place for those of us who live on land.但有十亿年之久Yet, for a billion years,海洋是地球唯一有生命的所在this was the only place on the planet where life existed.那些早期生物的后代Today, descendants of those early life forms活跃至今continue to thrive.它们跟鱼类共享大海但数量超出十倍They share the sea with fish, but outnumber them by ten to one.它们没有脊椎They have no backbones,而且演化出无数型态and have evolved into countless different forms.有些体型惊人拥有巨大脑部和高度智慧Some are huge, large-brained and intelligent.有些极为细小Others are minuscule,但建造出世上最大的自然结构yet build the largest natural structures on the planet. 它们是海洋无脊椎动物存活在深海的生物They are marine invertebrates, the creatures of the deep.它们群居在海洋的每个角落They have colonised every corner of the ocean,以出乎意料的and have a mind-boggling range of solutions多种方案解决生存难题to the problem of staying alive.海洋绝非完全一致The ocean is by no means uniform.深度，温度，阳光和水流的差异Differences in depth, temperature, sunlight and currents带来不同的问题pose particular challenges.在海面下两公里处的这些海底热泉One and a half miles down, these hydrothermal vents从地壳裂缝喷出摄氏四百五十度的spew out super-heated water at 450 degrees Centigrade超高温热水from cracks in the Earth's crust.虽然水压极高Despite the enormous pressure, the total darkness,周围一片漆黑水温更是炙人and the scaldingly-high temperatures,所有生命的祖先或许就在这种地方the ancestors of all life may have evolved演化诞生in a place just like this.庞贝虫之名Pompeii worms.来自它们耐高温存活的能力So named for their ability to survive volcanic heat.它们在热泉的邻居，包括蟹类和两公尺长的巨型管虫They share the vents with crabs and two-metre-long tube worms.它们只能在这里生存They can only survive here在热泉周围大量繁殖的细菌能填饱它们的肚子because they are able to feed on bacteria that thrive around the vents.这种栖地极为稀有These colonies are extremely rare.难怪多数生物都聚集在靠近海面之处Not surprisingly, most life thrives在这里觅食轻松许多nearer the surface, where feeding is considerably easier.这是磷虾类似虾子的细小甲壳动物These are krill, tiny shrimp-like crustaceans. 磷虾群数量惊人每立方公尺可高达六万只Swarms can reach astounding numbers - 60,000 per cubic metre.它们会在夜间浮上海面，吃浮游生物During the night they rise towards the surface to feed on plankton.在墨西哥的科提兹海Here, in the Sea of Cortez, off Mexico,磷虾群吸引各式掠食动物the swarms attract hunters of all kinds,从大翅鲸到大批食肉鱼类from humpback whales to shoals of predatory fish.有另一个猎人抵达了它来自深海Yet another hunter arrives. It's one from the deep. 这是美洲大赤鱿A Humboldt squid.身长两公尺当地人称为Two metres long, they have a local reputation吃人怪兽as man-eaters.光是一只美洲大赤鱿就够可怕Alone, they are formidable enough...但这次来了一群总共好几百只..but this is a pack... ..of hundreds.美洲大赤鱿是很聪明的猎人They are highly intelligent hunters.而且视觉敏锐Their eyesight is exceptional.它们有强壮触手吸盘环绕七万个钩子They have powerful tentacles, suckers ringed with 70,000 hooks还有能撕裂肌肉的尖锐喙嘴and a razor-sharp beak for tearing through flesh.现在鱼群发现自己遭受攻击Now the fish find that they are under attack于是集合起来以保安全and so group together for safety.但美洲大赤鱿采取团队合作把鱼群赶到岩石旁But the Humboldt squid work as a team, herding the fish against the rocks.有人认为乌贼变红和变白It's thought that the squid flash red and white不只是为了迷惑猎物not only to confuse their prey,也是要向同伴发出讯号指示何时发动攻击but also to signal to each other when they are about to attack.美洲大赤鱿的数量正在急速增加Humboldt squid numbers are growing rapidly.但它们仍然保持神秘But they remain mysterious.跟出现时一样迅速它们又消失在深海As fast as they arrived, they disappear back into the deep.在距离南极一千多公里的800 miles from the South Pole,活火山伊里布斯峰山脚下in the shadow of a smouldering Mount Erebus.冬季气温是冻寒的零下四十度Winter temperatures are a punishing minus 40.这里看似不可能有海洋生物存在This, perhaps, is the last place you might expect to find marine life.极地刚开始进入春季Now it's the beginning of the polar spring,冰层下的海水数月来首次有阳光照射and for the first time in months, light reaches the sea beneath the ice.这里极度寒冷It's extremely cold整年大半时间都是漆黑一片and completely dark for much of the year,所以环境很类似深海so conditions are not unlike those of the deep ocean.但麦克马多海峡生机蓬勃Yet, in McMurdo Sound, life flourishes.这里的动物生长速度极为缓慢The creatures here grow extremely slowly.但这表示它们能长到极大岁数和体型But that does mean they can reach a great age and great size,而且它们的数量惊人and they occur in surprisingly large numbers.三公尺长的食肉性纽虫Three-metre-long, carnivorous nemertean worms.还有红海星和海胆铺满整片海床Red sea stars and urchins carpet the sea floor.巨大的纽虫似乎什么都吃This monster-worm will eat almost anything而且不断在海床上搜寻食物and is constantly scanning the sea floor for food.动物在这里大批聚集是因为这个Animals are swarming here in such numbers because of this...一只小海豹的尸体..a dead seal pup.分量如此丰盛的大餐十年才会出现一次Such a great quantity of food may only arrive once in ten years.但海豹尸体不容易吃But a seal's body won't be easy to eat.纽虫有类似鱼叉的吻部Nemerteans have a snout like a harpoon,让它们能刺穿尸体的皮肤that enables them to puncture the skin of the corpse.红海星就比较辛苦It's harder work for the sea stars.它们进食时要从嘴巴吐出胃They feed by pushing out their stomachs through their mouths.这只红海星把胃抵在海豹皮肤上As this sea star presses its stomach against the seal's skin,然后分泌消化液溶解海豹的组织it secretes digestive juices that dissolve the seal's tissue.但这需要时间But that takes time.这支食腐大军整个夏季都会在这里大吃These scavengers will feed here throughout the summer,直到啃光海豹尸体until all that remains of the seal will be a skeleton,只剩骨骸stripped bare.浅水区仅占海洋世界的一小部The shallows are only a tiny part of the marine world.其中九成都是大海90% of it is open water.海流带着生物走过数千公里Its currents carry life for thousands of miles.水母正是这种流浪生活的大师The masters of this nomadic existence are jellyfish. 漂流在空荡海洋的生活很寂寞A life spent drifting in the empty ocean could be a lonely one...但这种水母例外but not for this jellyfish.这是海月水母Aurelia.它们聚集成群并非意外Swarms like this are not accidental.水温和水流都恰好时These individuals all hatched together这些水母会一起孵化when the temperature and currents were just right.这个时机能确保它们得以饱餐一顿，赶上浮游生物Their timing has ensured that they can make the most在夏季最后一次大量出现of feeding on a late-summer plankton bloom.水母没有脑部和血液Jellyfish have no brain and no blood.但它们有眼点But they do have eyespots that enable them可以分辨明暗to tell the difference between light and dark.透过简单的喷水推进And they can move independently of the current它们不靠海流也能独立行动by a simple form of jet propulsion.所有水母都有带刺触手用来捕捉食物All jellyfish have stinging tentacles with which to catch their food.它们弹动身体触手抓住浮游生物As they pulse their bodies, the tentacles trap plankton,然后送入位于身体中央的嘴巴which is then passed towards their mouth in the centre.十万只带刺水母群聚A swarm of 100,000 stinging jellyfish或许能吓跑掠食动物might seem a daunting prospect for a predator...但不包括这只..but not for this one.巨大的炒蛋水母A huge fried egg jellyfish.它是冷血杀手It is a killer.它的武器是覆盖在触手上的鱼叉状细胞Its weapons are harpoon-like cells that cover its tentacles.一接触到受害者When they come into contact with a victim,它立刻射出触手they spear it.接着炒蛋水母就拖入猎物The fried egg then hauls in its prey.少数幸运的海月水母成功逃脱A few lucky Aurelia do manage to pull themselves free.但多数受害者都But for the majority, there is only one outcome...难逃一死Death.一如大多数海洋无脊椎动物Jellyfish, like a great many marine invertebrates,水母有脆弱的柔软身体have soft, vulnerable bodies.它们有刺细胞保护They are protected by stinging cells.但还有其他的防卫方式But there are other kinds of defence.就是披上盔甲Armour plating.这些是蜘蛛蟹These are spider crabs.它们大半辈子都待在深海They spend most of their lives in deep water.但每年有一次在澳洲南部外海But once a year, off the coast of Southern Australia, 二十五万只蜘蛛蟹a quarter of a million crabs开始长途跋涉前往浅水区set off on a long journey to the shallows.它们来这里是因为一个共同问题They are here because they all share a problem.每只蜘蛛蟹身上的盔甲都已经穿了一年Each crab has been wearing the same suit of armour for a year now.现在紧绷到不舒服的地步And it's getting uncomfortably tight.所有螃蟹终究必须褪下旧壳So each crab eventually has to shed its shell制造更大的新壳and produce a bigger one.可以想象替换旧壳的步骤很棘手Replacing an old shell is understandably a tricky process.首先螃蟹First the crab必须先在旧壳内长出一层新皮肤grows an entirely new skin within the old shell.然后收缩身体迫使外壳It then flexes its body to force its shell沿着背部裂开to split along the back...然后缓缓后退，从旧壳离开..before gingerly backing itself out.蜘蛛蟹来这里不只要换壳还要进行交配The spider crabs are not only here to moult, but to mate.它们热切的把握这个机会And they grab the opportunity with considerable enthusiasm.然而像这样大批聚集有个缺点Coming together in such numbers does however have a drawback.这会吸引掠食动物It attracts predators.这是刺魟A stingray.虽然眼前有许多潜在猎物Despite there being so many potential prey,刺魟似乎视而不见the stingray seems to ignore them.或许人多势众真的比较安全Perhaps there's safety in numbers...但不是所有蜘蛛蟹都准备仰赖群体..although not all the crabs are prepared to rely on it.蜘蛛蟹群开始警觉起来Alarm spreads amongst the crabs.但其实多数螃蟹都很安全But in fact, most of them are safe.这只刺魟很挑剔This ray is being very choosy.它只对外壳最软It's only interested in the softest shelled,刚换好壳的蜘蛛蟹有兴趣most recently moulted crabs.一旦选中目标，它绝对手到擒来Once a target is singled out, there is no escape.当新壳变硬When their new armour has hardened,蜘蛛蟹就回到较安全的海底the crabs return to the comparative safety of the deep, 只留下它们褪下的旧空壳leaving behind only their old, empty shells.跟蜘蛛蟹一样多数海洋动物的行为Like spider crabs, the behaviour of most marine creatures都是由简单的神经系统控制is controlled by a very simple nervous system.但还是有例外But there are exceptions.这只乌贼是最聪明的海洋动物之一This cuttlefish is one of the cleverest animals in the ocean.这只母乌贼有很大的脑部She has a very large brain.根据身体比例In fact, it's larger for her size它的脑部比多数鱼类或爬虫类更大than that of most fish or reptiles.它的生活不只复杂，更充满谜题Her life is both complex and full of intrigue.澳洲巨乌贼通常独来独往Giant Australian cuttlefish usually live alone,但在短暂的生命中它们必须聚集一次进行交配but once in their short lives they must come together to mate.当这只母乌贼前往传统交配地As she approaches the traditional mating grounds,一只最大的公乌贼对它表示兴趣one of the largest males starts to show interest in her.它带公乌贼离开对手来到较安静的地点She moves him away from his rivals to a quieter spot -它将能在这里安全产卵a place where she will be able to lay her eggs in safety.Dialogue: 0,0:22:48.28,0:22:53.51,Default,,0000,0000,0000,,公乌贼用触手抓住母乌贼让它面向自己The male takes the female in his arms and turns her to face him,再用触手把精英放入母乌贼before using one of his arms to pass sacks of sperm嘴巴附近的开口to an opening near her mouth.交配完成后公乌贼在母乌贼上方徘徊Once mated, he hovers over her,守护母乌贼直到它产卵standing guard until she's laid her eggs.但公乌贼面临一个问题But he's got a problem.公乌贼的数量比母乌贼多四倍Males outnumber females four to one.所以它必须不断打退对手保住母乌贼So keeping her to himself is a constant battle.这个体型较大的对手不容易被吓跑This larger rival is more difficult to intimidate. 乌贼能以变化剧烈的Cuttlefish can make very dramatic changes皮肤图案表达情绪to their skin pattern in order to signal their moods.在侧身显现的鲜艳色彩和条纹Flushes of bright colour and stripes that pulse along his side,警告对手不要靠近tell the rival to keep off.多数对手在这时已经撤退这个却不愿离开Most rivals back down at this stage, but not this one.虽然公乌贼的闪亮讯号越来越强烈Although the male's flashing signals get more and more emphatic,到最后它别无选择只好出手打斗in the end, he has no choice but to fight.打赢的公乌贼可以回去守护母乌贼Victory! And the male can return to guard his female.乌贼是一流沟通者Cuttlefish are great communicators,但这种绝技有黑暗面but there is a flip side -它们也能成为诈欺高手they can also be masters of deception.这只公乌贼太娇小无法打斗争取交配机会This male is too small to fight for a mate, but he has another plan -但它另有一个狡猾计划and it's sneaky.它小心接近这对乌贼He approaches the couple cautiously,收起触手举在面前holding his tentacles tucked up at the front,模仿想要交配的母乌贼mimicking a female that wants to mate.为了完成伪装To complete his disguise,它还改变体色让自己更像女生he changes colour to appear even more like a female.站岗的公乌贼似乎上当了The guarding male seems convinced,或许它自以为鸿运当头maybe he thinks his luck is in -多了一只母乌贼让它征服another female to add to his conquests.这只奸诈的装扮公乌贼小心翼翼The sly, cross-dressing male接近母乌贼edges closer and closer to the female, holding his nerve.只要不被想交配的公乌贼抱住As long as he avoids being grabbed in a mating embrace,它的诡计就能得逞the sneak is safe.母乌贼已经猜出对方身分不明At what point the female guesses his true identity isunclear,但它并不挑剔but she isn't choosy,在大公乌贼的触手下and surreptitiously mates with him它们开始偷偷交配right under the larger male's tentacles.母乌贼准备产卵It's time for the female to lay her eggs.它用两只公乌贼的精子Using the sperm from both males,逐一让产下的卵受精she fertilises her eggs one by one然后把受精卵薪在一个隐密缝隙处的岩石上and glues them to a rock in a hidden crevice.如果幸运它将拥有两个父亲的孩子With luck, she will now have a mix of offspring.有些可能成为强壮公乌贼Some may become masterful males,有些则是个性奸诈and others, little sneaks.它可以说是毫无疏漏She'll have all the bases covered.这是卑诗省沿岸The coastal waters of British Columbia.这只四公尺长的北太平洋巨型章鱼住在这里Home to this four-metre-long Pacific Giant Octopus.它是可怕的掠食动物She is a formidable predator,但现在它不打算猎食but at the moment hunting isn't on her mind.这只母章鱼刚完成第一次交配She has just mated for the first time.现在要寻找安全庇护所And now she's searching for a safe refuge.它谨慎的选择She makes her choice carefully.未来几个月的家This is going to be her home for many months to come.这是它的育婴室It's her nursery den.这里的天花板吊着一百万颗卵100,000 eggs hang from its ceiling,它要用性命守护孩子and she's guarding them with her life.少了它的保护Without her to protect them,这些卵会被掠食动物吃光或染病they would be eaten by predators, or become diseased.它用触手抚摸未孵化的孩子She caresses them with her tentacles,确保这些卵不会长海藻也不会被鱼吃掉ensuring that algae don't grow on them, and that fish don't eat them.它持续让海水在卵周围流动She constantly keeps the water moving around them,让卵能获得充足氧气so they're well-supplied with oxygen.它照顾未孵化的孩子六个月She cares for them for six months,在这段期间什么都不吃and during all this time, she doesn't eat a thing.现在当卵开始孵化它也即将死去And now, as they are hatching, she is dying.小章鱼在某个晚上破卵而出One night, as the baby octopus emerge,它最后一次对孩子喷水she jets water over them for the last time,帮助它们出生helping them on their way.这将是它死前的最后动作This will be her final act.它只会生产这一次This is the only time she will reproduce,为了给孩子最佳存活机会它牺牲了生命and to give her young their best chance, she sacrifices her life.大海中体型最大Out of the depths comes one of the largest也最凶恶的海星，从深海出现and most aggressive starfish in the ocean.这只向日葵海星Pycnopodia,跟垃圾桶盖一样大a giant sunstar the size of a dustbin lid.它是猎人It's a hunter.每根触手都布满超敏感的管足Each arm is covered by super-sensitive tube feet,能靠触觉和嗅觉侦测到猎物that can detect prey by touch and smell.但海星也偏好腐肉But the sunstar is also partial to carrion,它发现巨型章鱼妈妈的尸体and it detects the carcass of the giant octopus mother. 它用触手上的迷你吸盘The miniature suckers on its feet clamp on to the corpse,紧抓尸体拖出洞穴and drag it out of the cave.其他食腐动物赶来共享大餐Other scavengers rush to join the feast.虽然身为骇人掠食动物Although it's a fearsome predator,向日葵海星并非所向无敌Pycnopodia doesn't have it all its own way.这些红海胆的速度来不及逃脱These sea urchins aren't speedy enough to escape,但它们有强悍的防卫but they do have a formidable defence.它们的尖锐棘刺难以突破The sharp spines are hard to get past,而且每根棘刺还能分别移动and, what's more, the urchins can move each spine independently,夹住海星伸出的触手pinching the starfish's probing arms.被一群红海胆群困住Trapped by an army of urchins,向日葵海星被一只巨大的普吉特海峡帝王蟹发现Pycnopodia is spotted by an enormous king crab.海星遇到了克星Pycnopodia has more than met its match,帝王蟹立刻扯下它的一根触手and within seconds, the crab rips off one of its arms. 但这只是暂时的不便But that is just a temporary inconvenience.海星失去的触手很快就能再生Starfish are able to quickly regrow a lost limb.巨大的无脊椎动物似乎最令人印象深刻The most impressive invertebrates may seem to be the giants,但有些最小的品种其实具有最重大的影响力but in fact it's some of the smallest that can make the biggest impact.这座岛屿的每一平方寸Every square inch of this island has been created都是由一种不断成长活生生的超级结构组成by an ever-growing, living superstructure,那就是珊瑚礁a coral reef.这么大的珊瑚礁需要数千年成长It's taken thousands of years to reach this size,这一切的起源是不到针头大小的动物and it all began with creatures smaller than a pinhead.珊瑚礁无法随处成长A reef can't be built just anywhere,它需要坚固的立足点it needs something to give it a firm footing.像这样的沉船，能作为绝佳地基A wreck like this provides an excellent foundation. 这艘沉船一落在海床上As soon as it settles on the sea bed,就遭遇入侵者的攻击the wreck comes under attack from invaders -那就是海流带来的浮游生物plankton, carried here by ocean currents.这些是藤壶，海绵动物These are the microscopic larvae of barnacles, sponges,以及最重要的珊瑚的细小幼虫and, most importantly, corals.珊瑚幼虫必须附着在沉船上The larvae must attach themselves to the wreck.它们就定位后发育成称为珊瑚虫的年轻珊瑚Once there, they can develop into young corals called polyps.但珊瑚虫成长速度极为缓慢But the polyps are very slow-growing,并且面临其他入侵者的激烈竞争and there is lots of competition from other invaders.海藻迅速覆盖沉船Algae quickly cover the wreck,对年轻珊瑚造成问题and that's a problem for the young coral.海藻会吸引食草动物Algae attract grazers.珊瑚虫在站稳脚步之前The polyps are in danger of being eaten就可能被吃掉before they've even got a proper foothold.如果条件合适幸存者就能继续建造珊瑚礁If conditions are right, the survivors can go on to build a reef.位置是关键因素Position is critical.太深的话没有足够阳光让珊瑚成长Too deep, and not enough light will reach the corals for them to grow.太浅则可能在退潮时暴露在空气中Too shallow, and they risk being exposed to the air at low tide.珊瑚礁要持续成长For the reef to really flourish,必须位于能带来食物的海流途中it also needs to be in the path of currents carrying food.让时间快转约六年Fast-forward half a dozen years or so,这艘沉船将首度出现肉眼可见的and the wreck will begin to show the first signs 珊瑚迹象of corals visible to the naked eye.再过十年，沉船将彻底改观A decade later, and the wreck will be transformed.数千只珊瑚虫将形成珊瑚丘Thousands of polyps will form coral heads覆盖住船壳that encrust its surface.这艘船是在二次大战期间沉没This ship was sunk during the Second World War,已经有足够时间形成大片珊瑚礁and there has been enough time for a substantial reef to develop.在成长数十年之后After decades of growth,不同品种的珊瑚各自占据沉船的一区different species of corals dominate particular areas of the wreck.成长最快的品种在边缘和两端突出部分最为茂盛The fastest-growing types grow best on the edges and overhangs,往外伸展到大海也向上争取阳光reaching far out into the water, and up to the light.它们只需要一小片区域就能开始成长They need only a small area to establish themselves,而且会迅速长出数十个珊瑚块或珊瑚枝上面挤满珊瑚虫yet they can rapidly grow dozens of plates, or branches,尽量吸收最多阳光crammed with polyps, to gather as much light as possible.成长较慢，也较结实的珊瑚例如这些脑珊瑚Slower-growing, much more robust corals like these brain corals,比较适合长在正在建造的珊瑚礁中央are better suited to the heart of the developing reef.它们能为珊瑚礁提供永续生长的稳固结构It's these that give the reef their structure and permanence.这里或许有近五百个珊瑚品种There could be nearly 500 different species here,各自在生锈船壳上奋力争取一席之地each striving to win a foothold on the rusting hulk.珊瑚的生活步调看似缓慢The pace of life for corals may seem to be so slow,很难想象它们也会竞争that it's hard to imagine that there is any conflict here.但在入夜后珊瑚礁的气氛转变But, as night falls, the mood on the reef changes.珊瑚其实极为好斗Corals are, in fact, extremely aggressive,为了扩展领地，它们会战斗至死and will fight to the death to expand their territory. 这是无法光荣撤退的战役There can be no honourable retreat,赢家会把敌人活活吃掉a winner will, literally, eat its enemy alive.沿着战斗前线敌对双方的珊瑚虫Along the battle front, the polyps of both combatants extrude their guts,吐出丝状的细长内脏long thread-like filaments,盖住敌人over their opponents.战线边缘是死去的珊瑚虫At the fringe, all that remains of the destroyed polyps仅存的骨骼are their skeletons.消化最快的珊瑚就是赢家The coral that can digest fastest, wins.珊瑚持续在Corals constantly grow死去同志的骨骼上成长over the skeletons of their dead comrades,建造出越来越大的珊瑚礁building a bigger and bigger reef.接着是一年一度的盛事在十一月满月过后几天Then, just once a year, a few days after the November full moon,珊瑚开始集体产卵the corals take part in a mass spawning event.数百万个卵和精子被释出到海中Millions of eggs and sperm are released into the water,结合成为幼虫and join,到处漂流寻找定居处to develop into larvae that drift in search of a place to settle.沉船的每一时船壳终将被占据Eventually, every inch of the wreck's surface will be colonised.钢铁会锈蚀消失珊瑚礁将独自屹立The steel will rust away, and the reef will be on its own.多数珊瑚礁的长成都是不靠沉船，自力救济Most reefs grow without the help of a wreck to start them off.只要时间够久就能建造出像这样的巨大结构But, given time, they can create something as huge as this,世上最大的活结构，大堡礁the Great Barrier Reef, the largest living structure on Earth.珊瑚礁的生物多样性甚至高过雨林A coral reef rivals even a rainforest for itsdiversity of life.但这些珊瑚是住在食物稀少的水域Yet corals like this are found in waters where food is very scarce.这里所有生物All the creatures here已经适应高度特化的不同生活方式have had to adopt a different and highly specialised way收集每一个有营养的碎屑to gather every nourishing scrap.圣诞树虫钻入珊瑚骨骼寻求保护Christmas tree worms bore into the coral's skeleton for protection,把身体卷成一圈探出用羽毛状的鳃抓取食物碎粒swirling out and grabbing food particles with their feathery gills.塔藤壶其实是龙虾的亲戚Coral barnacles are, in fact, related to lobsters.它们躺着挥舞长脚They lie on their backs,收集漂过的任何食物waving their feet to gather any food floating past.螃蟹演化出许多觅食方法Crabs have evolved many different ways of gathering food.这只瓷蟹的This porcelain crab前肢有呈扇形的细丝has a fan of filaments on his front legs.拳师蟹的双螯各抓着一只细小海葵A boxer crab attaches a tiny sea anemone to each fist.除了作为防卫As well as for defence,它也用海葵的黏性触手收集路过的浮游生物he uses their sticky tentacles to gather passing plankton.这只红毛猩猩蟹全身长满黏性细毛This orangutan crab's whole body is coated with sticky hairs,但现在它或许觉得太黏手了in this case, perhaps just a bit too sticky!这个奇特动物是海参This strange creature is a sea cucumber.它用触手从沉积物里抓取细小食物It uses its tentacles to grab food from the sediment.这里也有掠食动物例如这些海蛞蝓There are hunters here too, like these nudibranchs, or sea slugs.鲜艳体色是用来警告众人它们有毒Their vibrant colours are a warning that they're toxic.海蛞蝓有三千多个品种许多专门猎捕一种猎物There are over 3,000 species, many hunt just one specific prey.有些则是猎食彼此Some hunt each other.这只帝王虾善加利用它的宿主的有毒特性This emperor shrimp makes the most of the poisonous nature of its host.但它的宿主并没有好处But, it's a rather one-sided affair.在宿主进食时这只虾子有人保护，还能搭便车As it feeds, the shrimp gets protection and a free ride.其他虾子发展出较平衡的关系Other shrimps have developed a more balanced relationship.有些甚至还征求搭档Some even solicit for partners.这些虾子在为晚餐起舞These dance for their dinner.这些则在向路人宣传它们已经开张做生意And these advertise to passers-by that they are open for business.它们是除寄生虫小组They are a parasite removal team,为珊瑚礁的大批鱼群提供服务providing a service for countless fish on the reef,包括可以一口吃下它们的鱼including those that could happily eat them.这样的勇气当然有回报它们可以得到送上门的大餐In return for their bravery, they get a meal that comes to them.由最细小的动物组成的珊瑚礁Coral reefs, built by the tiniest of creatures,占据不到百分之零点五的海床occupy less than half of one per cent of the ocean's floor.但有四分之一的海洋生物仰赖珊瑚礁生存Yet they support a quarter of all marine species.海洋无脊椎动物包括珊瑚，乌贼和蟹类Marine creatures, all without backbones, from corals, to cuttlefish, to crabs,数量占海洋生物的多数make up the majority of life in the oceans.但它们对海洋以外的世界也有令人意外的But they have also had a surprisingly important impact重大影响beyond the marine world.它们的尸体化石，外壳和骨骼Their fossilised bodies, shells and skeletons形成石灰岩和白至如今覆盖了form the limestone and chalk that now covers huge tracts亚洲，欧洲和美洲的大片土地of Asia, Europe, and the Americas.海洋无脊椎动物体型虽小但在二十亿年的悠久历史中They may be small, but over their two billion-year history,它们确实改变了世界they have, literally, changed the world.为了拍摄本集部分的画面To capture some of the sequences in this episode,“生命制作”制作团队将水底摄影推向一个前所未有的境界the Life team had to take underwater filming into uncharted territory.有一次实地拍摄，摄影小组打算花上几个星期，潜入两公尺厚的冰层底下One shoot meant spending weeks diving under two metres of ice,另一次是在热带地区放置一个新的珊瑚礁地基another involved laying the foundation for a new coral reef in the tropics.一艘沉船可以作为珊瑚理想的生长地点A sunken ship can make an ideal location for corals to grow.正因如此，“生命脉动”制作团队决定要接受挑战So, with this in mind, the Life team set themselves a challenge...自己制造沉船事件to make their very own shipwreck.经过几个月的搜索After months of searching,他们在巴哈马找到一艘船可能很适合这次的任务they find a boat in the Bahamas that might be suitable.但是在把船沉入海底之前还得完成许多准备工作But there's a lot to do before it can be sunk to the sea bed.看得出来它已经被堆在这里多久了在码头八年了Apparently it's been here for。
