''Bythinella reyniesii'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of very small

freshwater snail Freshwater snails are gastropod mollusks that 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 t ...

, an

aquatic Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the family

Amnicolidae Amnicolidae is a family of small freshwater snails with a gill and an operculum, aquatic gastropod mollusks in the superfamily Rissooidea. This family is in the clade Littorinimorpha (according to the taxonomy of the Gastropoda by Bouchet & ...

Distribution

These snails live in

spring Spring(s) may refer to: Common uses * Spring (season), a season of the year * Spring (device), a mechanical device that stores energy * Spring (hydrology), a natural source of water * Spring (mathematics), a geometric surface in the shape of a he ...

s. They were long believed to occur only in

Andorra Andorra, officially the Principality of Andorra, is a Sovereignty, sovereign landlocked country on the Iberian Peninsula, in the eastern Pyrenees in Southwestern Europe, Andorra–France border, bordered by France to the north and Spain to A ...

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

, and parts of

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

. This disjunct distribution was puzzling, until it was realized that the populations assigned to several other supposedly distinct species actually seem to all belong to one species. In fact, ''Bythinella reyniesii'' is probably widespread from western

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

and nearby

Belgium Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...

through central and eastern France to Andorra.Bichain J.-M.. Gaubert P., Samadi S. & Boisselier-Dubayle M.-C. (2007). "A gleam in the dark: Phylogenetic species delimitation in the confusing spring-snail genus ''Bythinella'' Moquin-Tandon, 1856 (Gastropoda: Rissooidea: Amnicolidae)". ''

Molecular Phylogenetics and Evolution ''Molecular Phylogenetics and Evolution'' is a peer-reviewed scientific journal of evolutionary biology and phylogenetics. The journal is edited by E.A. Zimmer. Indexing The journal is indexed in: * EMBiology *Journal Citation Reports *Scopus ...

'' 45(3): 927–941.
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Description and genetics

These are small snails, with a nearly

cylindrical A cylinder () has traditionally been a Solid geometry, three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a Prism (geometry), prism with a circle as its base. A cylinder may ...

shell measuring just over 2 mm in length. There is little morphological and almost no genetic variation between the supposed "species". Thus, even though the proposed

synonymy A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

resulted from

mtDNA Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the DNA contained in ...

COI and

nDNA Nuclear DNA (nDNA), or nuclear deoxyribonucleic acid, is the DNA contained within each cell nucleus of a eukaryotic organism. It encodes for the majority of the genome in eukaryotes, with mitochondrial DNA and plastid DNA coding for the rest. It ...

ITS1

sequence In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is cal ...

data analyses applied to the

phylogenetic species concept A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of classification and ...

(which does not recognize

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

), as opposed to the morphologically diverse '' Bythinella bicarinata'' it might not even be warranted to accept the formerly distinct

taxa In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and ...

as subspecies.

Conservation status

The northeastern specimens formerly separated in ''Bythinella compressa'' were classified as Vulnerable (B1+2c), as they were known from less than ten freshwater springs which are affected by pollution. ''Bythinella reyniesii'', in the traditional sense was classified as a Species of Least Concern (meaning it is not considered globally threatened), and this assessment applies to the species in the expanded sense also.

References

{{DEFAULTSORT:Bythinella Reyniesii Bythinella Gastropods described in 1851 Taxonomy articles created by Polbot