Dwarf spring snails

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Dwarf spring snails
Belgrandiella edmundi, Sóller, Mallorca

Belgrandiella edmundi , Sóller , Mallorca

Systematics
Class : Snails (gastropoda)
Superordinate : Caenogastropoda
Order : Sorbeoconcha
Superfamily : Littorinoidea
Family : Sea snails (Hydrobiidae)
Genre : Dwarf spring snails
Scientific name
Belgrandiella
Wagner , 1928

The dwarf source screw ( Belgrandiella ) are a class of very small, in source waters of live snails in the family of hydrobiidae (Hydrobiidae). They are common in Europe . There are very many species, all of which have a small range with low populations.

features

The slim, cylindrical to egg-shaped shells of the dwarf spring snails are very small and no longer than 2.5 mm with up to four whorls. The egg-shaped to elliptical housing mouth has a thickened edge of the mouth at the mouth angle and in the area of ​​the navel, which forms a flat fold with the housing at the navel. The operculum is orange to red-brown in color.

Dwarf spring snails are separate sexes. The simple penis is regularly wide with no outgrowths or with a non-glandular flap on the inner edge in the middle position.

Distribution and way of life

All species of the Belgrandiella genus live in clear spring waters and upper reaches of the streams that spring from them. The species occur in isolation from one another and, as endemic species, each with a small population, are sensitive to changes in their habitat.

Discovery story

Because of their tiny size, the dwarf sea whale snails were discovered late. Of the species that belong to this genus today, the longest known thermal spring snail Belgrandiella parreyssii , which was found in the thermal spring of Bad Vöslau and described by Ludwig Georg Karl Pfeiffer in 1841 , but still under the name Paludina parreyssii . The type species Belgrandiella kusceri (Wagner, 1914) was not found until the beginning of the 20th century by the Polish zoologist Antoni Józef Wagner in springs on Lake Zirknitzer See in Innerkrain in what is now southern Slovenia and initially described as Belgrandia kusceri - after the Slovenian malacologist Ljudevit Kuščer . It was also Wagner who in 1928 established the Belgrandiella genus - named after the French civil engineer Eugène Belgrand . Until recently, new species of this genus were found and described in Austria as well.

threat

In the meantime, numerous species of Belgrandiella have been found in spring waters of Europe from Spain to Bulgaria . In Austria alone there are 11 species, all of which are classified as threatened species by the IUCN and 9 of which (all except Belgrandiella aulaei and Belgrandiella fuchsi ) are on the list of endangered species in Austria . The species are very difficult to distinguish, but due to their respective endemic occurrence, laypeople can also clearly identify them according to where they were found.

Occurrence of some species

Belgrandiella boetersi lives in the Fischbach Gorge near Schleedorf ( Salzburg ), the up to 1.9 mm high Belgrandiella mimula in the Warm Fischa in Bad Fischa in Lower Austria and Belgrandiella pelerei in the Fischa -Quelle near Haschendorf . The only 1.3 mm small Belgrandiella parreyssii lives in the thermal spring of Bad Vöslau and the Hansybach that flows from it . Belgrandiella ganslmayri can be found in the Kirchbichlbach southwest of Weyer (Upper Austria) on the Enns , while Belgrandiella aulaei is on the Rinnenden Mauer near Gradau and the Wunderlücke near Rabach . Belgrandiella fuchsi lives in springs near Kleinzell and Salzerbad

Belgrandiella fuchsii. The orange / red colored operculum is characteristic of Belgrandiella fuchsii .

, Belgrandiella wawrai in the Fürth Bach . Belgrandiella multiformis can be found in a single spring on the Kalten Rinne near the Weinscheinwand on the Semmering Railway near Breitenstein . In Styria three types are known: Belgrandiella Austriana in Andritz origin in Stattegg in Graz , Belgrandiella kreisslorum in Hohenberg (Stattegg community) and Belgrandiella styriaca in Bärenloch at Mixnitz .

Examples of other species are Belgrandiella kusceri in southern Slovenia near Lake Zirknitzer See (Cerkniško jezero) in its outflows (Karlovica, Svinjska jama / pig cave) and in Rakov Škocjan and Belgrandiella edmundi in a spring near Sóller on Mallorca .

Types (selection)

Austria
Slovenia
Bulgaria
Spain

literature

  • A. Wagner (1928): Studies on the mollusc fauna of the Balkan Peninsula with special consideration of Bulgaria and Thrace, together with monographic treatment of individual groups . Prace Zoologiczne Polskiego Panstwowego Muzeum Przyrodniczego [Annales Zoologici Musei Polonici Historiae Naturalis] 6 (4) (1927), pp. 263-399, plates 10-23. Warszawa.
  • Peter Glöer: The animal world of Germany. Mollusca I. Freshwater gastropods of Northern and Central Europe - identification key, way of life, distribution. 2. rework. Ed., 327 p., ConchBooks, Hackenheim 2002. p. 106. Genus Belgrandiella AJ Wagner 1927 . ISBN 3-925919-60-0
  • Martin Haase (1996): The radiation of spring snails of the genus Belgrandiella in Austria (Mollusca: Caenogastropoda: Hydrobiidae) . Hydrobiologia 319 (2), pp. 119-129.
  • Dilian G. Georgiev (2011): A New Species of Belgrandiella (Wagner 1927) . Acta Zoologica Bulgarica 63 (1), pp. 7-10.
  • Sanja Žagar: Favna polžev v izvirih okolice Cerkniškega jezera . Diplomsko delo, Ljubljana, Univerza v Ljubljani, Biotehniška fakulteta, Ljubljana 2012 (diploma thesis, Slovenian)

Web links

Commons : Thermen dwarf spring snail ( Belgrandiella parreyssii )  - Collection of images, videos and audio files