Zospeum
Cave dwarf horn snail ( Zospeum spelaeum )
Zospeum is a genus of tiny, live exclusively in caves snails, which are among the dwarf horn snails ( Carychiidae ) within the lung snails ( Pulmonata ). Due to their small size, they are also ( non- systematic) called Mikrogastropoden.
Features
The dextral housing are very small ( 1 to 2.5 mm high and 0.8 to 1.5 mm wide) and thin. Live animals have a transparent housing that receives a milky-white color after death. The cabinet surface is finished smooth or with spiral stripes. The mouth is lipped thickened, with a Parietalzahn and two spindle slats. The top spin Della Melle ends on the orifice wall.
The animals are true hermaphrodites, the insemination is however one-sided, ie one partner acts as the female, the other a male. Which acts as female animal is returned to the penis.
Geographical distribution, habitat and behavior
The representatives of the genus Zospeum are widespread Palaearctic; recently made discoveries in the caves of southern China and South Korea to expand the area considerably further east. Prior to this discovery, the area was limited to Europe. However, the membership of the Asian findings to Zospeum has yet to be secured.
The Zospeum species are exclusively inhabitants of caves and underground karst columns. They are found from sea level to 1850 m. The animals live in the constantly damp cave walls, on the floor of the cave or on rotting wood. They move, with only about 1 to 15 cm in the week, on average, about 7 mm per day, and this is usually at a temperature of below 10 ° C and a humidity 97-100 %.
Taxonomy and systematics
The genus is calculated according to the dwarf 's horn snails ( Carychiidae ), but which is treated partly as a family of the superfamily Ellobioidea, partly as a subfamily of the family of coastal snails ( Ellobiidae ). The number of species is still uncertain, since there is still no modern, comprehensive revision of the group. AnimalBase lists 17 species Fauna Europaea 21 species, with the AnimalBase listing a species that is absent in the Fauna Europaea. In addition, several subspecies are still distinguished. Other types are listed in the Mollusc Data Base:
- Genus Zospeum Bourguignat, 1856 Zospeum allegrettii Conci, 1956
- Zospeum alpestre ( Freyer, 1855) Zospeum alpestre alpestre ( Freyer, 1855)
- Zospeum alpestre kupitzense A. Stummer, 1984
- Zospeum alpestre bolei Slapnik, 1991
- Zospeum frauenfeldii frauenfeldii ( Freyer, 1855)
- Zospeum frauenfeldii osolei Slapnik, 1994
- Zospeum spelaeum spelaeum ( Rossmaessler, 1839)
- Zospeum spelaeum schmidti ( Frauenfeld, 1854)
The species are z.T. very poorly known, most are only defined gehäusemorphologisch. It is quite possible that some of them will prove to be synonyms, and the number of species could thereby reduce. On the other hand, the integration of molecular data yielded the finding that particular variable and widespread Zospeum Morphoarten contain several cryptic evolutionary lineages. Many of the species are known to only a small geographic region, or even as Höhlenendemiten.