Austrian spring snail
| Austrian spring snail | ||||||||||||
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Bythinella austriaca from Lower Austria |
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| Scientific name | ||||||||||||
| Bythinella austriaca | ||||||||||||
| Frauenfeld , 1857 |
The Austrian spring snail ( Bythinella austriaca ) is a rare species of the genus of the spring snail ( Bythinella ) from the family of the water snail (Hydrobiidae).
features
Austrian spring snails are very small, the shell is approx. 3.2 mm high and 1.6 mm wide and almost cylindrical in shape. The walkways are flattened on the sides, the last walkway takes up about 2/5 of the total height. The case itself is colorless and translucent in youth, white with age. Often they are covered with a brown or green coating of algae, especially in the case of springs in a bright environment.
Taxonomy
The source snails can only be anatomically determined with certainty on the basis of the sexual organs . Also sequencing of DNA must often be used. Older information based on empty shells can therefore be problematic, as some species are very similar to one another.
Glöer (2002) names four subspecies :
- Bythinella austriaca austriaca Frauenfeld, 1857
- Bythinella austriaca conica (Clessin, 1910)
- Bythinella austriaca Ehrmanni (Pax, 1938)
- Bythinella austriaca pavovillatica (Canon, 1937)
Bythinella hungarica is either a synonym or a subspecies of Bythinella austriaca (Feher et al. 2006).
distribution
Bythinella austriaca is widespread in Eastern Central Europe and Eastern Europe, especially in the catchment area of the Danube, but often only occurs locally. So far over 1000 occurrences are known in the Alpine-Carpathian region in Austria, Germany, Poland, Slovakia, Hungary and the Czech Republic. Finds from Ukraine are still to be examined; finds from Romania have recently been assigned to a different species (Falniowski et al. 2009). The now widely scattered occurrences can be interpreted as relics of a once - under different climatic conditions - coherent distribution.
Way of life and ecology
Spring snails largely need constant temperatures in their habitat. They live almost exclusively in cold springs and the adjacent upper reaches of streams or rivers and are so-called pointer types for pure water. More than 1000 animals per square meter can live in suitable habitats. In some regions several different species occur in the same source.
They are highly specialized and therefore very well adapted to the extremely nutrient-poor, actually hostile habitat. Due to the low ecological amplitude, they react to changes in their habitat within a short period of time with a decreasing number of individuals or even local extinction.
It is spread by larger animals, on which snails or their eggs are transported from one source to the next. Spring snails feed on diatoms , blue algae and green algae as well as bacterial films in the springs and on fallen leaves and pieces of wood in the water.
Danger
Spring snails are endangered by spring capture (especially in dry regions where there are hardly any unmounted springs and many streams therefore dry up) and construction work in the vicinity of the springs. The use of springs as cattle troughs, the construction of drainage systems and falling groundwater levels are also problematic. Excessive fertilization and the entry of nitrogen from the air lead to eutrophication of the springs.
The IUCN classifies the species as "Least concern" due to its large distribution area. In Austria Bythinella austriaca is on the pre-warning list. According to the "Red List of Internal Mollusks [snails (Gastropoda) and mussels (Bivalvia)] in Germany", the population of the Austrian spring snail is endangered.
supporting documents
literature
- Frauenfeld, G. von (1857): About the paludines from the group of Paludina viridis Poir . Seat area Akad. Wiss. mathematic science Classe, 22 (2): 569-578, 1 Table, Vienna, page 574.
- Glöer, P. (2002): The freshwater gastropods of northern and central Europe . In F. DAHL, Die Tierwelt Deutschlands , 73rd part. ConchBooks: Hackenheim.
- Falniowski, A. & Magdalena Szarowska (2009): Sequence-based species delimitation in the Balkan Bythinella Moquin-Tandon, 1856 (Gastropoda: Rissooidea) with general mixed yule coalescent model . Folia Malacologica.
- Patzner, RA (2008): Mollusc of the year 2008 - Bythinella austriaca . Nature and Land, Salzburg.
- Fehér, Z., G. Majoros, A. Varga (2008): A scoring method for the assessment of rarity and conservation value of the Hungarian freshwater molluscs . Heldia 6, 127-140.
- Feher, Z., Haase, M. & Reischutz, P .: Bythinella austriaca . In: IUCN 2012. IUCN Red List of Threatened Species . Version 2012.2.
Individual evidence
- ↑ JH Jungbluth, D. von Knorre (with the assistance of U. von Bössneck, K. Groh, E. Hackenberg, H. Kobialka, G. Körnig, H. Menzel-Harloff, H.-J. Niederhöfer, S. Petrick, K Schniebs, V. Wiese, W. Wimmer, ML Zettler): Red list of internal mollusks [snails (Gastropoda) and mussels (Bivalvia)] in Germany. Announcements of the German Malacoological Society, 81: 1-28, Frankfurt / M. 2009 PDF ( Memento from June 16, 2013 in the Internet Archive ) (1.3 MB)
Web links
- Bythinella austriaca inthe IUCN 2013 Red List of Threatened Species . Posted by: Feher, Z., Haase, M. & Reischutz, P., 2010. Accessed February 15, 2014.