Lessepsian migration

The Lessepssche migration is the exchange of organisms between the Mediterranean Sea and the Red Sea, after a connection is created with the construction of the Suez Canal (opened in 1869) under the direction of Ferdinand de Lesseps. It therefore is an invasion biological process; the allochthonous species are considered in their new habitat as alien species.

The construction of the Suez Canal two Faunengebiete were interconnected. This led to the migration of a variety of species from the Red Sea into the Mediterranean; in the reverse direction, the hike was much lower. The best way to observe the migration of fish, but also other, less conspicuous organisms spread out through the channel.

That especially the fauna of the eastern Mediterranean has been changed, is that it resembles, in its climatic conditions and its food supply in many ways more like a tropical oligotrophic sea ( such as the Red Sea) but almost exclusively inhabited by the colder Atlantic over before the sewer has been.

In the various Vergletscherungsphasen the last ice age, the sea level worldwide fell several times by up to 200 meters from ( eustatic sea level fluctuation). The Mediterranean was cut off during these phases from the Atlantic and shrank sharply. However, many species died out. A re- colonization in the meantime warm periods of the Ice Age was only made ​​possible by the Atlantic Ocean, the living world was not so well adapted to the ecological conditions of the Mediterranean. Even the Red Sea shrank strongly several times, but was re- colonized by the significantly better adapted to the local environmental conditions, species from the Indian Ocean. This also explains that the eastern Mediterranean has only about 550 species of fish, compared with about 800 in the Red Sea.

Before the canal construction there has been no accurate inventory of the organisms of both seas. It is thought that about 500 species migrated to the Mediterranean and about 50 species in the Red Sea. Among the species that reached into the Mediterranean, is one example, the jewelry lobster, which is caught commercially today also off the coast of Israel, and the mullet ( Upeneus vittatus ), called Sultan Ibrahim, who is for the fishermen Syria of economic importance.

The eight-year lockout after the 1967 Six Day War, in which the channel was calm and clear, caused a significant further migration boost. Since the spread in the Mediterranean takes place almost exclusively along the coast, the invasive species spread initially mainly to the east and north, because the path to the west was blocked by the brackish water zone of the Nile Delta. This changed with the construction of the Aswan Dam, which greatly reduced the extent of the brackish water zone.

Examples

Here are some examples of fish species that have spread in the Eastern Mediterranean due to the Lessepsschen migration:

  • Striped Catfish ( Plotosus lineatus )
  • Fistularia commersonii from the kind of flute fish
  • Stripes Hussars fish ( Sargocentron rubrum)
  • Indian lionfish (Pterois miles)
  • Leiognathus klunzingeri
  • Upeneus moluccensis
  • Upeneus pori
  • Indian Mackerel ( Rastrelliger kanagurta )
  • Rotmeer Pennant (Heniochus intermedius )
  • Pyramid boxfish ( Tetrasomus gibbosus )

Here are some crustaceans:

  • Charybdis helleri
  • Portunus pelagicus
  • Marsupenaeus japonicus
Range (biology) Tetrosomus gibbosus
508524
de