Ophel (biome)

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The Ophel is the opinion of some Biospeläologen According to a global underground biome , which is characterized by a large and previously unrecognized level of biodiversity distinguished and mostly on the by chemautotrophic based bacteria recovered energy. The theory was first formulated in 2007 by the Israeli zoologist Francis Dov Por , the reason for the discovery of the Ajalon Cave in Israel, in which a number of endemic animal species living in isolation from the outside world were found.

Isolated ecosystems

Until a few years ago it was considered certain that underground biosystems would always be sustained by biomass that was photosynthetically generated on the earth's surface and fed vertically. After the discovery of ecosystems in the deep sea, in the vicinity of black smokers , cold seas and at the bottom of the Black Sea , the existence of biotic communities based at least in part on chemoautotrophy was proven. In addition, there were investigations in closed cave systems, such as the Movile cave .

Ajalon cave

Eight animal species were found in the Ajalon Cave, discovered in 2006. Of the four types of crustaceans , three were previously unknown. The lack of juveniles or egg-bearing females led to the assumption that Typhlocaris ayyaloni and Tethysbaena ophelicola only visit the cave lake in the Ajalon cave for food intake and that they reproduce in the surrounding groundwater . From this it followed in turn that there was a transport of biomass from the cave lake into the surrounding groundwater body. This possible horizontal transport of energy is the basis for the theory of a global, subterranean biome that is independent of the input of energy from outside, which Francis Dov Por calls "Ophel".

The Ophel

The name is the Hebrew word for "darkness" or "underworld". In the ophel, sulfur bacteria and other chemoautotrophic bacteria form biomass from sulfur-containing thermal water, and higher organisms feed on the bacteria.

The thesis of the worldwide extent of the ophel is based on the spread of crustaceans of the order Thermosbaenacea , which is represented in the Ajalon cave with Tethysbaena ophelicola . The order is distributed worldwide with 36 species, it is only unknown from South America. Without exception, these crustaceans show a strong adaptation to high temperatures, oxygen-poor waters and the diet of chemoautotrophic bacteria. The dominance of the Thermosbaenacea in ecosystems like the Ajalon Cave is associated with the fact that their oxygen transport is based on hemocyanin , which is superior to hemoglobin when it is very warm and oxygen- poor . Their worldwide distribution is regarded by Por as an indication of a likewise worldwide expansion of the Ophel.

According to Por, the Ophel is bound to the groundwater currents, which on the one hand can be blocked by numerous geological phenomena, but on the other hand can also flow beneath lakes and shallow seas and thus connect the underground fauna of islands with the Ophel. The Ophel's biodiversity hotspots are those areas where low-salt, cool groundwater flows mix with escaping thermal water. In doing so, Por attaches importance to the fact that the Ophel is not a relic from earlier geological epochs, but an independent biome that continues to expand and in which evolutionary adaptations are still taking place. Finally, also inspired by the discovery of the Ajalon Cave, Por drew the picture of three global, overlapping biospheres : the chemoautotrophic bacteriosphere deep in the earth's crust, which requires neither light nor oxygen, the deuterobiosphere , which is above-ground due to bacterial chemosynthesis and a low input Oxygen and includes the ophel , and the photosynthesis-based eubiosphere above ground .

criticism

Por's theory did not meet with unqualified support. The Romanian zoologist Ştefan Negrea pointed out that there can be no completely isolated systems in nature. In relation to the Movile cave, too, it was initially assumed that it was completely isolated from the outside world. In the meantime it has been proven there that the immigration of animals was possible through cracks in the 14 meter thick sandstone, for example with the centipede Cryptops anomalans . Por, however, considers this to be impossible for the Ajalon cave because of the more than one hundred meters thick layer of hard limestone above the cave.

Individual evidence

  1. ↑ a b c Francis Dov Por: Groundwater life: some new biospeleological views resulting from the Ophel paradigm , p. 63.
  2. ↑ Francis Dov Por: Deuterobiosphere the chemosynthetic Second Biosphere of the Globe. A First Review , p. 101.
  3. ↑ Annette Summers Engel: Chemoautotrophy In: William B. White, David C. Culver (Eds.): Encyclopedia of Caves. Second Edition , Academic Press, Waltham, MA 2012, pp. 125-134, here pp. 125-126, ISBN 978-0-12-383832-2 .
  4. ↑ Francis Dov Por: Deuterobiosphere the chemosynthetic Second Biosphere of the Globe. A First Review , p. 102.
  5. ^ A b Francis Dov Por et al .: Animal life in the chemoautotrophic ecosystem of the hypogenic groundwater cave of Ayyalon (Israel) , pp. 10-11.
  6. ^ Francis Dov Por: Ophel, the Newly Discovered Hypoxic Chemolithotrophic Groundwater Biome: A Window to Ancient Animal Life , p. 465.
  7. ↑ Francis Dov Por: Deuterobiosphere the chemosynthetic Second Biosphere of the Globe. A First Review , p. 103.
  8. ^ Francis Dov Por: Ophel, the Newly Discovered Hypoxic Chemolithotrophic Groundwater Biome: A Window to Ancient Animal Life , p. 474.
  9. ^ Francis Dov Por: Groundwater life: some new biospeleological views resulting from the Ophel paradigm , p. 67.
  10. ^ A b Francis Dov Por: Groundwater life: some new biospeleological views resulting from the Ophel paradigm , p. 68.
  11. ^ Francis Dov Por: Groundwater life: some new biospeleological views resulting from the Ophel paradigm , p. 69.
  12. ^ Francis Dov Por: Groundwater life: some new biospeleological views resulting from the Ophel paradigm , p. 71.
  13. ^ Francis Dov Por: Groundwater life: some new biospeleological views resulting from the Ophel paradigm , pp. 71-72.
  14. ^ Francis Dov Por: Groundwater life: some new biospeleological views resulting from the Ophel paradigm , p. 74.
  15. ↑ Ştefan Negrea: A remarkable finding that suggests the existence of a new groundwater biome based on chemoautotrophic resources, named "Ophel" by FD Por , pp. 90-91.
  16. ↑ Francis Dov Por: Deuterobiosphere the chemosynthetic Second Biosphere of the Globe. A First Review , pp. 104-105.
  17. ↑ a b c d Ştefan Negrea: A remarkable finding that suggests the existence of a new groundwater biome based on chemoautotrophic resources, named "Ophel" by FD Por , p. 86.

literature