(完整版)BBC生命第四集

第四集：鱼类

我们的地球是颗蓝色的行星Ours is truly a blue planet.

水覆盖了大部分地球表面Water covers most of the world's surface.

在这里我们是旁观者Here we are the outsiders.

但碧波之下，有种生物却很兴盛But under the waves one group thrives.

鱼类是水中高手Fish are masters of the waters.

旗鱼又是所有鱼中最快的And sailfish are the fastest of them all.

速度使它们成为海洋里最可怕的食肉动物之一Their speed makes them one of the ocean's most fearsome predators.

墨西哥海域，30条旗鱼包围着一群沙丁鱼Off the coast of Mexico

要抓到猎物，不仅仅单靠速度To catch their prey requires more than speed alone.

急转弯时，鱼鳍依旧结实In the tightest turns

它们靠镰刀形的尾巴驱动前进Their sickle-shaped tail powers them forwards

外形奇特的背鳍能够恐吓猎物and that extraordinary dorsal fin helps intimidate their prey.

肉眼看来，它们的动作太快了To the naked eye

慢镜头下，它们的战术才清晰呈现slowed

选定一个目标非常困难Just picking a target is hard enough.

通过敲打使它失去平衡，并将之从鱼群里孤立出来Knocking it off balance

这需要极高的技巧This requires extraordinary skill.

并非每次尝试都能成功Not every attempt is successful.

但随着越来越多的旗鱼加入，一个失手，另一个迅速跟上But as more sailfish join in

这群沙丁鱼被有条不紊地猎食殆尽The shoal of sardines is methodically wiped out.

旗鱼是顶级猎食者，极少生物能威胁到它们Sailfish are top predators

对大多数的鱼类来说，不是这回事But for the majority of fish this is not the case.

开阔的海洋对它们是极度危险的For most fish the open ocean is extremely dangerous.

有些能作出惊人之举，只为逃生And some go to extraordinary lengths just to survive.

飞鱼Flying fish.

靠超长的鳍，它们飞出水面Free of the water they soar on elongated fins

将猎食者远远甩在后面leaving their predators far behind.

鱼类的飞行家A flight of fish.

飞鱼所面临的考验，不仅仅只是逃避天敌Escaping predators is not the only test facing the flying fish.

它们也必须保护发育中的后代They must also protect their developing young.

飞鱼在寻找一种特殊的东西，使之成为可能These flying fish are searching for the one thing that will make this possible.

在如此辽阔的海洋里，并不容易In such a vast ocean it's not easy.

它们很幸运They're in luck.

一片棕榈叶A palm frond.

海洋里漂流的微型岛屿It's a tiny island adrift in a huge ocean.

它可以提供庇护所，但不是为飞鱼And like an island it offers shelter

而是给它们的卵but for their eggs.

雌鱼在叶子上产卵，雄鱼使它们受精The females lay eggs on the raft

一条鱼的排卵会引发其它的鱼也开始排卵The first fish spawn and this triggers the others to start.

不一会儿，成千上万条鱼参与进来Soon thousands join the melee.

产下难以计数的卵Innumerable strands of eggs are laid.

重压之下“木筏”开始倾斜The raft starts to tilt under their weight.

最佳产卵地点在叶子的中间The best place to lay eggs is right inside the frond.

有些尝试被证明是失败的，它成了一些鱼的坟墓For some the attempt proves fatal and living fish become entombed.

在如此多鱼卵的重压下，它开始下沉The raft starts to sink under the weight of so many eggs. 但这并非灾难But this is far from a disaster.

沉到水面以下，实际上可以提高鱼卵的存活机会Sinking away from the surface actually improves the eggs' chances of survival.

在深处安全地躲避着，几天后In just a few days

它们全都孵化出来they'll hatch out.

其它的鱼则用不同的方式保护后代Other fish protect their offspring in different ways.

有些在照料后代方面走的更远Some go to far greater lengths to care for them.

澳大利亚南部的浅水区The shallow waters of southern Australia

是许多奇异生物的家园are home to many strange creatures.

童话般的海马王国It's a fairytale world of sea horses...

占星鱼（一直瞪着眼看天空）..stargazers...

鳐鱼..and stingrays.

但谁也比不上海藻龙的美丽But none compare with the beauty of the weedy sea dragon.

它的背鳍快速地震动The dragon's tiny fins beat frantically

防止自己被水流冲走to prevent the current from sweeping it away.

现在是早春It's the beginning of spring

海藻龙的求爱期开始了the season when sea dragons begin their courtship.

在夜光下，它们开始跳舞And in the evening light

在优美的二重奏里，一只龙能准确地模仿伴侣的动作In a graceful duet

夜色很快就将这一对儿笼罩Darkness will soon draw a veil over the pair

但它们会继续跳舞，直到深夜but they will dance on

两个月后，它们的爱情结晶就会出现Two months later

雄性海藻龙，它是携带着卵的那只It's the male and he's the one that's carrying the eggs

一排一排的固定在它的尾巴上with rows and rows of them embedded in his tail.

那一夜，雌性将卵移交给了它That night the female transferred her eggs to him.

从那以后，它将独自照看这些卵Since then

这样随身带着它们可以保证安全By carrying them with him he's kept them safe.

现在，是它的付出得到回报的时候了And now it's time for his efforts to be rewarded.

卵开始孵化The eggs are ready to hatch.

在一个宁静的夏日早晨In the calm of a summer morning

一个还带着卵囊小海龙诞生了 a baby sea dragon

海藻床为能够自己觅食的The weed bed shelters older dragons

成年海龙提供庇护that are already able to feed themselves.

尽管这些小海龙从父亲那里得到了很好的照料Although these dragons were well cared for by their father

如今，它们必须独自寻找食物now they must find their own way in the world.

然而，还有一种鱼There are fish