Eight hitherto unknown species of invertebrate creatures isolated from the outside world for millions of years have been discovered in a unique subterranean ecosystem functioning in a cave in central Israel.
A team of scientists from Hebrew University said yesterday they had discovered the new species of crustaceans and scorpion-like animals in a cave uncovered during rock drilling at a cement quarry near Ramle.
The creatures include an omnivorous blind five-centimetre crustacean which the team have established as the highest in the food chain, capable of devouring other creatures as well as bacteria also found among what the scientists said were "exciting sediments" in the cave.
One of the team, Dr Hanan Dimentman said that the creature had three "relatives" in the Jordan Valley, and in the eastern Mediterranean off the coasts of southern Italy and Libya. But the team said that biomolecular analysis and DNA testing had already established that the crustacean and the other seven species were unique. The species are now being sent to experts in Europe and Israel for naming and classification.
Except for one species of blind scorpion all the creatures, which include both aquatic and terrestrial species, were found alive. But Dr Dimentman, of the university's Alexander Silberman Institute of Life Sciences, said he was confident that living scorpions would soon be discovered. "The eight species found thus far are only the beginning of what promises to be a fantastic biodiversity," he added.
Professor Amos Frumkin of the Hebrew University Department of Geography said the site - which scientists have named the Ayalon Cave - was "unique in the world" and had remained isolated because it was impenetrable to water.
Israel Naaman, a research student, described how he had initially used ropes to get through an underground passage into the cave 100 metres below the quarry close to the main Tel Aviv Jerusalem highway. With its branches, the cave extends over 2.5km before coming upon an underground lake. There Mr Namaan said he discovered a "small shrimp in the water," which prompted the team to carry out further investigation.
The university said yesterday that two of the crustaceans were seawater species while two others are of a type found in fresh or brackish water - suggesting that their ancestors may have had a link with the sea in prehistoric times.
The absence of sunlight in such caves means that plants cannot produce chemical energy by photosynthesis. Instead, life has to depend for its energy on the oxidation of subterranean minerals such as hydrogen minerals and hydrogen sulphide and they are then eaten by larger organisms.
Professor Frunkin said: "This is the most probable source of energy in the cave although the idea has yet to be tested." He showed a slide of large crystal-like deposits in the cave, which he said were unlike the stalagmites and stalactites often found in other caves.
The scientists said the lake was part of the Yarkon-Taninim aquifer, one of Israel's two main aquifers, but was different in temperature and chemical composition from the main waters of the aquifer. They added: "The lake's temperature and salinity indicates its source is deep underground."