Halicephalobus mephisto
Encyclopedia
Halicephalobus mephisto is a species of nematode
, among a number of other roundworms, discovered by geoscientists Gaetan Borgonie and Tullis Onstott
in 2011. It was detected in ore recovered from deep rock fracture water in several gold mines in South Africa
0.9 km (0.559235462984826 mi), 1.3 km (0.807784557644749 mi), and 3.6 km (2.2 mi) under the surface of the Earth. Onstott said that "it scared the life out of me when I first saw them moving," and explained that "they look like black little swirly things." The finding is significant because no other multicellular organism
has ever been detected farther than 2 km (1.2 mi) below the Earth's surface.
Halicephalobus mephisto is resistant to high temperatures, it reproduces asexually
, and feeds on subterranean bacteria. According to radiocarbon dating
, these worms live in groundwater
that is 3,000–12,000 years old. The worms are also able to survive in waters with extremely low levels of oxygen, lower than one percent of the level of most oceans. It is named after Mephistopheles
, which means "he who loves not the light" and alludes to the fact it is found so deep under the Earth's surface.
It is the "deepest-living animal" ever found, able to withstand heat and crushing pressure, and the first multicellular organism found at deep subsurface levels. A previously known species found at similar depths in the same study was Plectus aquatilis. Borgonie said that the worm was similar to the detritus feeding
species found on the surface, and probably descended from surface species. Such species are also able to survive extremes of temperature, and so, for Borgonie, the fact the first animal discovered at this depth was a worm was unsurprising. The team hypothesised that the species was descended from animals on the surface that were washed down the earth's crust by rainwater.
Halicephalobus mephisto worms measure from 0.52 to 0.56 mm in length. Though species in the genus Halicephalobus have few distinguishing features, H. mephisto can be differentiated from other species within its genus by its comparatively long tail, which is between 110 and 130 micrometres in length. It is closely related to H. gingivalis, but more closely related to certain unnamed species of the genus.
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
, among a number of other roundworms, discovered by geoscientists Gaetan Borgonie and Tullis Onstott
Tullis Onstott
Tullis Onstott is a professor of geosciences at Princeton University who has done research into endolithic life deep under the Earth's surface. In 2007, Onstott was listed among Time Magazine's 100 most influential people in the world...
in 2011. It was detected in ore recovered from deep rock fracture water in several gold mines in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
0.9 km (0.559235462984826 mi), 1.3 km (0.807784557644749 mi), and 3.6 km (2.2 mi) under the surface of the Earth. Onstott said that "it scared the life out of me when I first saw them moving," and explained that "they look like black little swirly things." The finding is significant because no other multicellular organism
Multicellular organism
Multicellular organisms are organisms that consist of more than one cell, in contrast to single-celled organisms. Most life that can be seen with the the naked eye is multicellular, as are all animals and land plants.-Evolutionary history:Multicellularity has evolved independently dozens of times...
has ever been detected farther than 2 km (1.2 mi) below the Earth's surface.
Halicephalobus mephisto is resistant to high temperatures, it reproduces asexually
Asexual reproduction
Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...
, and feeds on subterranean bacteria. According to radiocarbon dating
Radiocarbon dating
Radiocarbon dating is a radiometric dating method that uses the naturally occurring radioisotope carbon-14 to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years. Raw, i.e. uncalibrated, radiocarbon ages are usually reported in radiocarbon years "Before Present" ,...
, these worms live in groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
that is 3,000–12,000 years old. The worms are also able to survive in waters with extremely low levels of oxygen, lower than one percent of the level of most oceans. It is named after Mephistopheles
Mephistopheles
Mephistopheles is a demon featured in German folklore...
, which means "he who loves not the light" and alludes to the fact it is found so deep under the Earth's surface.
It is the "deepest-living animal" ever found, able to withstand heat and crushing pressure, and the first multicellular organism found at deep subsurface levels. A previously known species found at similar depths in the same study was Plectus aquatilis. Borgonie said that the worm was similar to the detritus feeding
Detritivore
Detritivores, also known as detritophages or detritus feeders or detritus eaters or saprophages, are heterotrophs that obtain nutrients by consuming detritus . By doing so, they contribute to decomposition and the nutrient cycles...
species found on the surface, and probably descended from surface species. Such species are also able to survive extremes of temperature, and so, for Borgonie, the fact the first animal discovered at this depth was a worm was unsurprising. The team hypothesised that the species was descended from animals on the surface that were washed down the earth's crust by rainwater.
Halicephalobus mephisto worms measure from 0.52 to 0.56 mm in length. Though species in the genus Halicephalobus have few distinguishing features, H. mephisto can be differentiated from other species within its genus by its comparatively long tail, which is between 110 and 130 micrometres in length. It is closely related to H. gingivalis, but more closely related to certain unnamed species of the genus.