Explorers entering this dangerous cave must wear respirators and carry monitors. Poisonous gases rise to fatal levels so quickly that an early warning system is essential. Bats survive by staying close to the skylights, but venturing deep into the cave is very dangerous indeed. The source of these toxic fumes lies several miles below. Hydrogen sulfide gas bubbles up from oil deposits in the earth's crust. It mixes with oxygen in the water, and forms sulfuric acid. These are not the sort of conditions in which you'd expect to find fish, yet these cave mollies seem to thrive despite the acid and the low levels of oxygen. There is, in fact, more life here than anyone would think possible, but the biggest surprise is something altogether more bizarre.


进入这个危险洞穴的探险者必须戴上呼吸器和监测仪。有毒气体很快会升到致命的水平，所以早期预警系统必不可少。蝙蝠通过紧贴出口来生存，但是进入到洞穴里面是十分危险的。这些毒气源位于几千米的深处。硫化氢气体不断从蕴藏在地壳下的石油中冒出来，它与水中的氧气化合形成硫酸。在这样的环境下我们通常认为不会有鱼存在，但是这种洞栖帆鳍鱼将却数量很多，尽管有硫酸，而且氧气缺乏。事实上，这里的生物数量比人们想象的多得多，但最大的意外还在于一种更奇异的东西。