(单词翻译:单击)
Sponges are very effective filter feeders, since they are able to capture and eat particles as small as bacteria as well as much larger particles.
海绵是非常高效的滤食动物，因为它们能够捕获并吃掉像细菌一样小的颗粒，以及更大的颗粒。
They might not look like they are doing much, but a simple demonstration shows how effectively sponges can pump water.
它们看起来可能做得并不多，但一个简单的演示可以显示出海绵泵水的效率有多高。
On a reef in the Caribbean, I make a dive with a syringe filled with a non-toxic dye called fluorescein.
在加勒比海的一个礁石上，我在潜水时，带了一个注射器，里面装满了一种叫做荧光素的无毒染料。
By squirting it around the base of some sponges, we can observe how the water is moving by watching what the dye does.
把它喷在某些海绵的底部，我们可以通过观察染料的移动来了解水的流动情况。
Within only seconds, the dye is pumped through the sponges along with the water.
在短短几秒钟内，染料和水一起被泵过海绵。
As you can see, a sponge is a pretty good water pump, and also a good strainer.
如你所见，海绵是一个很好的水泵，也是个不错的过滤器。
Any plankton that goes in with the water, won't come back out through the osculum.
任何与水一起进入海绵体内的浮游生物，都不会跑出出水孔。
Tube sponges are even more spectacular to observe.
观察管状海绵则更为壮观。
They pump the dye so furiously that they look like a collection of miniature smoke stacks!
它们狂暴地喷着染料，看起来就像一群微型的烟囱！
The ultimate test is a hefty barrel sponge!
最后测试的是一个巨大的桶状海绵！
What will a big monster like this do?
这样大的怪物会做什么呢？
It takes a few seconds for the dye to work its way through the sponge…but then it pours out like smoke from a chimney.
几秒钟后染料就会在海绵里流动，但随后会像烟囱里的烟一样喷出来。
That's pretty good pumping from those tiny little collar cells!
从那些小小的襟细胞里抽出来的水真不错！
Since sponges can't get together to reproduce, they spawn in a way similar to coral.
由于海绵不能聚在一起繁殖，所以它们的产卵方式与珊瑚相似。
The sperm is released into the water column by the male sponge and finds its way to the female sponges, where fertilization occurs internally.
精子被雄性海绵释放到水柱中，随后进入雌性海绵，在其体内受精。
Eventually, the planktonic larvae are released from the female sponge and float around in the water column as plankton for only a few days.
最终，浮游生物的幼虫从雌性海绵中释放出来，作为浮游生物在水柱中漂浮数天。
They then settle down and start growing.
然后它们会安定下来，开始生长。
Sponges don't have many predators.
海绵没有多少掠食者。
There is not much nutritional value in a sponge and they're hard to digest.
海绵没有多少营养价值，而且很难消化。
Hence, very few animals can eat sponges.
因此，很少有动物能吃海绵。
But something was clearly eating this sponge!
但很明显，有些动物可以吃掉海绵！
A sea turtle is the culprit.
海龟就是元凶。
Sea turtles are one of the principal predators of sponges, along with a few species of fish and some invertebrates like nudibranchs.
海龟是海绵生物的主要捕食者之一，还有一些鱼类和海蛞蝓等无脊椎动物也吃海绵。
Sponges might not be very exciting and they certainly don't have much personality, but they're an ancient animal that has been living in the oceans for at least half a billion years!
海绵可能不会让人感到非常兴奋，它们个性也不鲜明，但它们是一种远古动物，在海洋中生活了至少5亿年！
They can't crawl around, or swim, but they are very good at reproducing and feeding themselves by pumping water.
它们不会四处爬动，也不会游泳，但它们非常擅长通过泵水来繁殖和进食。
So, chances are, sponges will continue to populate the oceans longer than people will populate the Earth.
因此，海绵在海洋中的生存时间可能要比人类在地球上的生存时间更长。
