Pontocaspis

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Location of the Pontokaspis

Pontokaspis describes a region on the Eurasian continent with the center in the western part of the Eurasian steppe . The region is named after Pontos or Pontus , the ancient name of the Black Sea ( Pontos Euxeinos ) and the Caspian Sea ; its steppe area was also known as the Wild Field .

Biogeographical region

Vegetation zones

Flora and vegetation

In phytogeography and vegetation, no Pontocaspic region is usually recognized. The Pontic or Pontic-Pannonian flora province north of the Black Sea and the drier Iranian-Turanian region of Central Asia are separated from each other by the mountain belt of the Caucasus , they have numerous common species, but only a few that are exclusively common to them. There are very few Caspian endemics in the flora, so that a Caspian region is not differentiated here. The south and west coast of the Caspisees form the Hyrkanian region, which has close floristic relationships to the flora of the Caucasus and Transcaucasia, which is called Colchian, and the eastern Turkish Black Sea coast. There are very few species common to the steppe region in the north.

fauna

Terrestrial fauna

In the case of land-living ( terrestrial ) fauna, the delimitation and identity of a Pontocaspic region is less clear. Species with an origin or distribution center in the western part of the Eurasian steppe belt are referred to as pontocaspic .

Limnology

In limnology , the Pontocaspic biogeographical region is one of the faunistic regions into which the European continent is divided according to the composition of limnofauna . The region also includes areas of bordering West and Central Asia. These include the Black Sea with the Sea of ​​Azov , the Caspian Sea, the Aral Sea and the rivers and streams that flow into it, especially the Danube , Don , Dnepr , Dniester and Volga . This does not include, for example, the southern Balkans south of the Danube lowlands, the Anatolian southern coast of the Black Sea, the Caucasus and the northern Russian and Baltic tributaries of the Baltic Sea.

The Pontokaspis emerged from the Paratethys , a former marginal sea of ​​the southern ocean of Tethys . This was the Sarmatian separated before about 12 million years ago from the ocean, in its place is a vast, alkaline lake, the Sarmatian sea. The region has a complicated history with enlargements (transgressions) and reductions (regressions) of the water areas, in which today's separate waters repeatedly came into contact with each other, which meant that fauna was still possible. They were often accompanied by a marked change in salt content ( salinity ). Accordingly, species that cope well with changing salinity ( euryhaline species) are particularly characteristic .

The Pontocaspian fauna is particularly rich in crustaceans . 450 Pontocaspic species are counted here, 209 of which are endemic to the Caspian Sea. The region's fish fauna is not only the most biodiverse in Europe, but also has the most endemic species. This includes many carp fish and the gobies of the subfamily Benthophilinae.

Outgoing neozoa

Numerous species of the Pontokaspis have now been carried off to other regions by humans, above all through the connection of previously separate catchment areas through the construction of shipping canals and the carry-over in the ballast water of ships. Ballast water has even transported a number of species across the oceans, as a result of which some Pontocaspic species have developed into feared, invasive neozoa in the American Great Lakes, for example . In European waters, too, the neozoa with the greatest number of individuals with the most serious ecological influence belong to the Pontocaspic species, including the zebra mussel , the great humpback shrimp and the freshwater tube crayfish . The immigrants are so numerous locally that they make up the majority of the individuals and a relevant proportion of the species in many large rivers, so that in the long term their entire native fauna could be threatened.

Individual evidence

  1. ↑ cf. Flora in: Internet Encyclopedia of Ukraine .
  2. ↑ Liliya A. Dimeyeva: Phytogeography of the northeastern coast of the Caspian Sea: native flora and recent colonizations. In: Journal of Arid Land , Volume 5, No. 4, 2013, pp. 439–451, doi : 10.1007 / s40333-013-0175-x .
  3. ^ HJ Dumont: The Caspian Lake: History, biota, structure and function. In: Limnology and Oceanography 43, No. 1, 1998, pp. 44-52.
  4. ↑ Vladimir Mamaev: The Caspian Sea - enclosed and with many endemic species. Europe's biodiversity - biogeographical regions and seas. European Environment Agency, 1992.
  5. ↑ Melania EA Cristescu, Paul DN Hebert, Teodora M. Onciu: Phylogeography of Ponto-Caspian crustaceans: a benthic - planktonic comparison. In: Molecular Ecology 12, 2003, pp. 985-996.
  6. ^ Melania EA Cristescu, Paul DN Hebert: The “Crustacean Seas” - an evolutionary perspective on the Ponto-Caspian peracarids. In: Canadian Journal of Fisheries and Aquatic Sciences 62, 2004, pp. 505-517, doi : 10.1139 / F04-210 .
  7. ↑ Yorick Reyjol, Bernard Hugueny, Didier Pont, Pier Giorgio Bianco, Ulrika Beier, Nuño Caiola, Frederic Casals, Ian Cowx, Alcibiades Economou, Teresa Ferreira, Gertrud Haidvogl, Richard Noble, Adolfo de Sostoa, Thibault Vigneron, Tomas Virbickas: Patterns in species richness and endemism of European freshwater fish. In: Global Ecology and Biogeography 16, 2007, pp. 65-75.
  8. ↑ Matthew E. Neilson, Carol A. Stepien (2009): Escape from the Ponto-Caspian: Evolution and biogeography of an endemic goby species flock (Benthophilinae: Gobiidae: Teleostei). In: Molecular Phylogenetics and Evolution 52, 2008, pp. 84-102, doi : 10.1016 / j.ympev.2008.12.023 .
  9. ↑ Stefan Nehring: Alien Species in German Waters - A Risk for Biodiversity ( Memento of the original from November 17, 2013 in the Internet Archive ) Info: The @1@ 2Template: Webachiv / IABot / www.stefannehring.de archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 718 kB) Series of publications by the Federal Ministry of Food, Agriculture and Consumer Protection "Applied Science", issue 498.
  10. ^ B. Gallardo, DC Aldridge: Is Great Britain heading for a Ponto – Caspian invasional meltdown? In: Journal of Applied Ecology 2014, doi : 10.1111 / 1365-2664.12348 .