The North Atlantic right whale is one of the rarest species of whale on the planet numbering only about 411.

北大西洋露脊鲸是地球上最稀有的鲸鱼物种之一，大约只有411头。

As its numbers grew, many other species' numbers and habitats shrank.

随着其数量的增加， 许多其他物种的数量和栖息地都在缩小。

But strength in species numbers is also key to the health of ecosystems ranging from potato fields to rivers to the inside of your gut.

但物种数量的强弱也是生态系统健康的关键，从土豆田到河流，再到你的肠胃内部。

And crinoids are still around, too, but their species number in the 600s, in contrast to the 6000 known species that've lived throughout Earth's history.

海百合也仍然存在，但它们的物种数量只有 600 种，而地球历史上已知的物种数量为 6000 种。