Using the examples of Leafy Sea Dragon and the Cuttlefish, describe two kinds of camouflage and the benefits they provide.
请以叶海龙和墨鱼为例描述两种伪装手段和它们带来的益处。
Now listen to part of a lecture in a biology class.
请听生物课上的部分内容。

Now many sea animals, in order to hide from predators, have, over time,
很多生活在海里的动物为了躲避捕食者，经过时间的推移，
developed different kinds of camouflage to help them blend in with their environment and avoid detection by predators.
进化出了不同类型的伪装手段来帮助它们融入周围的环境，不被捕食者察觉。
Picture the surface of the sea floor, it's as varied as the land we live on.
可以想象一下海床表面的样子，它和我们生活的陆地一样富于变化。
It's got peaks and valleys, vegetation, rocky areas,
海底也有山峰、峡谷、植物和岩石区。
and some sea animals have developed permanent colors or shapes to resemble these environmental features.
而一些海里的动物进化出了和这些特色环境类似的，永久的颜色或形状。
This camouflage helps to disguise them from predators by enabling them to blend into, uh, a specific part of the sea.
这种伪装通过帮助它们融入海底某个具体部分来隐藏行迹。
For instance, take a kind of fish like the Leafy Sea Dragon, well, the name says it all,
就以叶海龙这种鱼类为例吧，它的名字就说明一切了，
it resembles a small green dragon with leaf-like protrusions sticking out like arms.
叶海龙是一种长着叶子一样的突出物的绿色小海龙，它身上叶子形状的突出物像手臂一样露在外面。
Now because its colors and shapes, it blends in extremely well with green sea plants.
凭借身体的颜色和形状，叶海龙在绿色海生植物中可以隐藏得特别好。
So when the Leafy Sea Dragon is swimming through these plants, predators have trouble seeing it.
所以当叶海龙在这些植物中游过时，捕食者很难发现它的身影。
But when it enters other environments without these green plants, its camouflage doesn't work any more.
但是，当它进入没有这些绿色植物的其他环境中时，它的伪装就起不了作用了。
Now other sea animals are difficult to spot anywhere in the sea
还有一些海生动物无论在海里哪个地方都很难发现它们的踪影，
because their type of camouflage enables them to change color.
因为它们拥有的伪装手段可以让它们变换颜色。
Take the Cuttlefish, a fish that is closely related to the squid and octopus,
比如墨鱼，这种鱼是枪乌贼和章鱼的亲戚，
unlike Leafy Sea Dragons, Cuttlefish have not developed any particular shape to hide from predators.
和叶海龙不同的是，墨鱼并没有进化出任何特别的形状来躲避捕食者。
But, uh, they have a lot more mobility because their camouflage allows them to blend in to any environment,
但是，它们有更多机动性，因为它们的伪装手段使它们可以融入任何环境，
because Cuttlefish have shifting pigments that allow them to change color in a matter of seconds,
这是因为墨鱼体内有可以不断变化的色素，它们能在几秒内变换颜色，
and, so they can almost instantaneously match their color of their surroundings.
因此它们几乎可以瞬间变成和周围环境一样的颜色。
If they're swimming by green sea plants, they'll turn green.
当它们在绿色海生植物旁游过时，它们会变成绿色。
And if they're swimming over the brown sea floor, they'll turn brown.
而当它们游过褐色的海床时，就会变成褐色。