Movile Cave has been cut off for millions of years. Its air is thick with harmful gases, yet it is home to an array of strange animal.
In the south-east of Romania, in Constanța county close to the Black Sea and the Bulgarian border, there lies a barren featureless plain. The desolate field is completely unremarkable, except for one thing.
Below it lies a cave that has remained isolated for 5.5 million years. While our ape-like ancestors were coming down from the trees and evolving into modern humans, the inhabitants of this cave were cut off from the rest of the planet.
Despite a complete absence of light and a poisonous atmosphere, the cave is crawling with life. There are unique spiders, scorpions, woodlice and centipedes, many never before seen by humans, and all of them owe their lives to a strange floating mat of bacteria.
“The pool of warm, sulphidic water stinks of rotting eggs or burnt rubber when you disturb it as hydrogen sulphide is given off.”
In the lake room, the atmosphere is heavy with harmful gases, principally carbon dioxide as well as the hydrogen sulphide from the water.
What’s more, the air is low in oxygen: it contains just 10% oxygen rather than the usual 20%.
Despite the dark and the dangerous gases, Movile Cave is crawling with life. So far 48 species have been identified, including 33 found nowhere else in the world.
There are all sorts of scuttling and slithering things. Snails and shrimps try to avoid the spiders and waterscorpions. In the air bells, leeches swim across the water and prey on earthworms.
Strangely, the worse the air gets the more animals there are. It’s not at all obvious why that should be, or how the animals survive at all.
http://www.bbc.com/earth/story/20150904-the-bizarre-beasts-living-in-romanias-poison-cave