The deepest-dwelling land animal in the world has been found almost 2 kilometres underground. Fittingly, its home is Krubera-Voronja, the world’s deepest cave, whose bottommost point is 2191 metres below its mouth.The cave is located near the Black Sea in Abkhazia, a breakaway republic of Georgia.
The arthropod, known as Plutomurus ortobalaganensis, was discovered 1980 metres below the surface, where it feeds off fungi and other decaying matter. Three other new species were also found lurking in the cave: Anurida stereoodorata, Deuteraphorura kruberaensis and Schaefferia profundissima. All four species have been classified as springtails, a type of small primitive wingless insect. Living in total darkness, the species all lack eyes. However, A. stereoodorata compensates for this with a highly specialised form of chemoreceptor.
The animals were discovered by Ana Sofia Reboleira from the University of Aveiro, Portugal, and Alberto Sendra of the Valencian Museum of Natural History, Spain. They were exploring the Krubera-Voronja cave as part of a 2010 expedition led by the Ibero-Russian CaveX team.
Before this discovery, springtails had been found just half a kilometre below ground. In 1986, Ongulonychiurus colpus was found living 550 metres down in Spanish caves, and last year, Tritomurus veles was found at 430 metres in caves in Croatia. The discovery of species living deep underground in total darkness gives new insights into the extreme conditions in which animals can survive.