''Belgrandiella parreyssi'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of minute

freshwater snail Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs ...

with a gill and an operculum, an aquatic

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the family

Hydrobiidae Hydrobiidae, commonly known as mud snails, is a large cosmopolitan family of very small freshwater and brackish water snails with an operculum; they are in the order Littorinimorpha. Distribution Hydrobiidae are found in much of the world, ...

. This species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

where it is found only in one thermal spring at Bad Voeslau, south of Vienna. Due to man made changes of the habitat the population has been decreasing rapidly since the 1970s.

References

Bibliography

Ludwig Karl Georg Pfeiffer Ludwig Karl Georg Pfeiffer, also known as Louis Pfeiffer (4 July 1805 – 2 October 1877), was a German physician, botany, botanist and conchology, conchologist. Early life, Education & Medical Career Louis Pfeiffer was born in Cassel, the eldes ...

(1841). Beiträge zur Molluskenfauna Deutschlands. Archiv für Naturgeschichte 7 (1): p. 227: Paludina, 1. P. Parreyssii Hydrobiidae Belgrandiella Endemic fauna of Austria Gastropods described in 1841 Taxonomy articles created by Polbot Taxa named by Ludwig Karl Georg Pfeiffer {{Hydrobiidae-stub