听力文本

This is the price that these cave commuters must pay for their daytime sanctuary underground.
这是洞栖动物必须付出的代价，以换取它们白天在陆地上的庇护
Small wonder, then, that there are other cave dwellers that stay put.
难怪其它洞穴生物要终生居住在洞穴中。
Many caves are like islands, cut off from the outside world and from other caves.
很多洞穴都和岛屿一样，与外界及其它洞穴隔绝。
This isolation has resulted in the evolution of some very strange creatures.
这种孤立环境导致进化产生各种各样奇怪的生物。
They are the cave specialists, troglobites, animals that never emerge from the caves or see daylight.
它们都是洞穴专家，穴居动物--从不出洞并且永远不见天日的动物。

These troglobites from Thailand are possibly the most specialised creatures on Earth,
泰国的这些穴居动物可能是地球上最奇特的动物
for they live only in cave waterfalls.
因为它们只生活在洞穴瀑布中
The entire population of these cave angel fish seems to be restricted to just two small caves.
世界上所有的洞穴天使鱼，可能只存在于两个较小的洞穴中。
It's the same story with other troglobites.
其它穴居动物也是同样的情况
There may well be less than 1 00 Texas cave salamanders in the wild.
世界上可能只有不到100只野生洞栖童态河溪螈。

视频及简介

洞穴是不受阳光控制的生物栖息地之一，但这并不意味着那里就不存在野生生物。本集节目将深入洞穴内神秘而永恒的黑暗，探索山洞、洞穴和隧洞中未知的地下世界。