European country leech
| European country leech | ||||||||||||
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Young European leech ( Xerobdella lecomtei ) |
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| Scientific name | ||||||||||||
| Xerobdella lecomtei | ||||||||||||
| Frauenfeld , 1867 |
The European land leech ( Xerobdella lecomtei ) is a leech from the family Xerobdellidae . Unlike the medicinal leech from the Hirudinidae family , it does not feed itself by sucking blood .
The leech was in 1867 in Austria near Leoben by Theophile Le Comte, a member of the Natural Scientific Society of Styria, discovered and Georg Ritter von Frauenfeld (1807 to 1873), a famous naturalist who the Natural History Museum in Vienna co-founded, for the first time described .
features
The European country leech is about 4 cm long and has three jaws. Two tentacles in the area of the mouth opening can be pushed back into the oral cavity and are usually not visible. However, they carry chemical sensory organs that play an important role in tracking down prey. Similar to other belt worms , the European land leech is adapted to life in moist forest soils in temperate climates . As a member of the leech family Xerobdellidae , it is not a close relative of the tropical land leeches from the Haemadipsidae family . It differs from these anatomically in the position of the nephridia and physiologically in the food intake, which is not exclusively parasitic by sucking blood from other animals, as is the case with landing leeches from the tropics. The common German name "Landblutegel" is therefore misleading.
nutrition
After rainfall, the European land leech was often observed on or in the company of amphibians . In the 19th century, this often led to the assumption that he was a bloodsucker, e.g. B. on the alpine salamander , could feed. However, nutritional experiments have shown that the amphibians in his habitat play no role in his food acquisition. On the other hand, it feeds on various little bristles , mainly earthworms , but also fly larvae and occasionally small snails . Smaller animals are usually devoured in their entirety. If the leech meets larger prey, it can attack them and use its jaws to cut the tissue and cut it into bite-sized pieces. In some cases earthworms are then completely or partially sucked out with the help of the specialized digestive organs.
Occurrence
A 1951 publication on the ecology and way of life of the European land leech speaks of a “widespread distribution” of the species in the Austrian Eastern Alps , but also indicates that this species is “difficult to find” because of its hidden way of life. There are also finds of the species from Slovenia .
In the 1960s, some of the country leeches were collected in the moist soil of beech forests in the area around Graz (Austria). Thereafter, no further find for the European land leech was published until 2003. After a two-year search in the forests of Graz, the evolutionary biologist Ulrich Kutschera and colleagues reported in 2007 that they had found an approximately 1 cm long young animal. This "Lonely George the Annelids " - named after the last male Galapagos tortoise - was cultivated in the laboratory and its eating behavior was documented.
Systematic position
After the death of the animal, genetic material ( DNA ) was extracted and analyzed. The DNA gene sequence of the Xerobdella individual is on file (COI GenBank no. EF125040). Molecular genetic studies have shown that the European land leech is an evolutionary line of its own . The genus Xerobdella includes two other species that are known from the Italian Southern Alps. It forms the family Xerobdellidae with the genus Mesobdella widespread in South America (Chile) and the Central American genus Diestecostoma . Due to the distribution pattern of the very weakly dispersed species, there is speculation about the origin of the stem line on the urcontinent Pangea with subsequent radiation.
Climate change and population development
The decline in the Grazer country leech population, which seems to be largely extinct in this area, is most likely due to climate change . In the Graz region, the average summer temperature rose by 3 ° C between 1961 and 2004. This warming of the air led to a drying out of the soil where the rare land leeches live.
The conclusion was drawn that human-made global warming, which has so far largely accompanied the environment in Central Europe without any visible damage to the environment, can lead to the extinction of populations of cold-adapted, less mobile species. These subtle human interventions in the evolution of hidden organisms have received little attention so far.
Since 2007, isolated specimens of Xerobdella lecomtei have been found in cooler, higher-lying forest regions around Graz . Nevertheless, the European land leech is so rare that fewer than 100 animals have been collected since it was first described (1867).
Individual evidence
- ^ Georg von Frauenfeld: Zoological Miscelles XIV. 1. A new landing gel from Austria. Presented at the meeting of November 6, 1867, negotiations of the Imperial-Royal Zoological-Botanical Society in Vienna, 18, pages 147–149, 1868 ( facsimile at Biodiversity Heritage Library, first description)
- ↑ a b Erich Reisinger : Way of life and distribution of the European country leech (Xerobdella lecomtei Frauenfeld). In: Carinthia II . 141st year, Klagenfurt 1951, pp. 110–124 ( PDF on ZOBODAT ).
- ^ Tone Novak (2005): Terrestrial Fauna from Cavities in Northern and Central Slovenia, and a review of systematically ecologically investigated cavities. Acta Carsologica 34 (1): 169-210.
- ↑ a b Ulrich Kutschera, Ina Pfeiffer, Ernst Ebermann: The European land leech: biology and DNA-based taxonomy of a rare species that is threatened by climate warming. Natural Sciences, 94, pages 967-974, 2007
- ↑ http://www.ncbi.nlm.nih.gov/nuccore/EF125040
- ↑ Elizabeth Borda, Alejandro Oceguera-Figueroa, Mark E. Siddall (2008): On the classification, evolution and biogeography of terrestrial haemadipsoid leeches (Hirudinida: Arhynchobdellida: Hirudiniformes). Molecular Phylogenetics and Evolution Volume 46, Issue 1: 142-154. doi : 10.1016 / j.ympev.2007.09.006
literature
- Georg von Frauenfeld: Zoological Miscelles XIV. 1. A new landing gel from Austria. Presented at the meeting of November 6, 1867, negotiations of the Imperial-Royal Zoological-Botanical Society in Vienna, 18, pages 147–149, 1868 ( facsimile at Biodiversity Heritage Library, first description)
