The 'Mongolian Death Worm', called olgoi-khorkhoi by the local population is a legendary animal with an unconfirmed existence that has preoccupied the imagination of the inhabitants and travelers in the region. It is said to inhabit the southern Gobi Desert where it terrorizes travelers with its deadly abilities to project acid that, upon contact, turns anything it touches yellow and corroded.
Two new sub-species of earthworms, Eisenia nordenskioldi mongol and E. n. onon, are reported from the same region. Although neither of them possesses the fatal characteristics of olgoi-khorkhoi, the sibling species exhibit the ability to partly regrow body parts when cut in two. Relatives of the sub-species are found in habitats as diverse as high mountains, deserts and geothermal hot-springs. They demonstrate extreme temperature tolerances and survival ranges thriving in environments from as little as -30°C up to +40°C.
E. nordenskioldi mongol has its name derived from the region of discovery. The name E. n. onon bears more romantic connotations, being inspired by the Onon River in Outer Mongolia, where Genghis Khan was born and grew up. The region is also supposed to be the resting place of this historical figure that inspires stories of great conquests, victories and brutality.
Earthworms as a group organisms have other more tangible, importance from an ecological point of view. Charles Darwin, for example, spent 50 years of his working life studying these humble worms. They are key organisms for monitoring and maintaining soil fertility. Earthworms are also the basis of food-chains as the Early-bird and any fishermen knows.
Whether olgoi-khorkhoi really exists, and whether the two new sub-species of the Siberian E. nordenskioldi species-complex are in any way related to it, is yet to be confirmed and in the meantime, can continue to inspire the romantic mind and stories.
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More information: Blakemore RJ (2013) Earthworms newly from Mongolia (Oligochaeta, Lumbricidae, Eisenia). ZooKeys 285: 1–21, doi: 10.3897/zookeys.285.4502