(Photo credits left: G. Borgonie, Ghent University, Belgium; Scanning electron microscope (SEM) image, face view of H. mephisto; center: G. Borgonie, Ghent University, Belgium; glass beads where nematodes were found living in the brownish colored bacterial biofilm; right: Esta Van Heerden, University of the Free State, South Africa; Borehole water from the Beatrix gold mine where H. mephisto was discovered)
Name: Halicephalobus mephisto
Common Name: Devil’s Worm
How it made the Top 10: Measuring about 0.5 mm in length, these tiny nematodes are the deepest-living terrestrial multicellular organisms on earth. Discovered at a depth of 1.3 km (8/10 mile) in a South African gold mine, this species is remarkable for surviving immense underground pressure as well as high temperatures (37o C / 98.6 o F). According to the authors, carbon dating indicated that the borehole water where this species lives had not been in contact with the earth’s atmosphere for the last 4,000 to 6,000 years. The discovery of H. mephisto in Earth’s deep subsurface is also significant because it may have important implications for the discovery of life at similar subterranean depths on other planets.
Etymology: mephisto in reference to the Faust legend of the Devil “because the new species is found at a depth of 1.3 km in the Earth’s crust.”
Type Material: Holotype – Museum voor Dierkunde, Ghent University, Belgium. Paratypes – Museum voor Dierkunde, Ghent University, Belgium and the University of the Free State, Bloemfontein, South Africa.
Type Locality: “collected from shaft 3, level 26, corridor 28 of Beatrix gold mine, South Africa, approximately 1 km north of shaft 3 (28 ͦ 149 24.0699 S, 26 ͦ 479 45.2599 E).”
Reference: Borgonie,G., García-Moyano, A., Litthauer D., Bert, W., Bester, A., van Heerden, E., Möller, C., Erasmus, M. & Onstott, T.C. (2011). Nematoda from the terrestrial deep subsurface of South Africa. Nature 474: 79 – 82.