A few kilometers from the Black Sea, in Romania, is the Movile Cave, which has been sealed for the last 5.5 million years. Within it, life has developed isolated from the rest of the planet, which is why it is considered a biological treasure.
The site was discovered in 1986, when workers in the Soviet Union were looking for new land to build a nuclear power plant. However, they were unable to access its deepest chamber, blocked by a series of limestone tunnels and vertical shafts.
One of the first attempts to explore this chamber was documented in an article published in Science in 1996, as a team of biologists from the University of Cincinnati gained access to this never-before-seen ecosystem.
Once inside, they found that the air contains less than half the oxygen compared to outside. Likewise, high levels of carbon dioxide and hydrogen sulfide were recorded, toxic air for much of life on Earth.As if all this were not too hostile, the cavern is in complete darkness, so it has not received a single ray of sunlight in the last millions of years.
Strange species
In the study carried out by the team of biologists, 48 species were identified, of which 33 were totally new to science.The previously unpublished creatures included spiders, pseudoscorpions, centipedes, woodlice, leeches, snails, and others that were discovered in further study.
Due to the absence of light, most of these animals have no vision and lack pigment.One characteristic that many of the species had in common was long limbs and antennae that help them navigate in the dark.
Unique ecosystem on the earth’s surface
The research also determined that this cave harbors the first known ecosystem to be based on chemosynthetic microorganisms.Most ecosystems are based on photosynthesis, the process by which organisms use sunlight for energy. However, in a totally dark environment, the bacteria get their energy from chemical reactions like ammonium oxidation or sulfide oxidation.
For this reason, the Movile Cave has the terrestrial ecosystem most similar to that found in hydrothermal vents, located in the deepest parts of the ocean, where microorganisms do not have access to sunlight and resort to chemosynthesis.
Decades have passed since humans entered this place, but experts believe that there are still many species to discover. This is a fascinating possibility for biology, since we have the opportunity to continue to observe the outcome of evolution in a small dark world.
