生命（2009）

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 its diversity 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