Bythinella reyniesii
Encyclopedia
Bythinella reyniesii is a species
of very small freshwater snail
, an aquatic
gastropod mollusk in the family Amnicolidae
.
s. They were long believed to occur only in Andorra
, Austria, and parts of France. 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 and nearby Belgium
through central and eastern France to Andorra.
and almost no genetic variation between the supposed "species". Thus, even though the proposed synonymy resulted from mtDNA COI
and nDNA ITS1
sequence
data analyses applied to the phylogenetic species concept (which does not recognize subspecies
), as opposed to the morphologically diverse Bythinella bicarinata
it might not even be warranted to accept the formerly distinct taxa as subspecies.
(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.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of very small freshwater snail
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....
, an aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
gastropod mollusk in the family Amnicolidae
Amnicolidae
Amnicolidae is a family of small freshwater snails with a gill and an operculum, aquatic gastropod mollusks.This family is in the superfamily Rissooidea and in the clade Littorinimorpha...
.
Distribution
These snails live in springSpring (hydrosphere)
A spring—also known as a rising or resurgence—is a component of the hydrosphere. Specifically, it is any natural situation where water flows to the surface of the earth from underground...
s. They were long believed to occur only in Andorra
Andorra
Andorra , officially the Principality of Andorra , also called the Principality of the Valleys of Andorra, , is a small landlocked country in southwestern Europe, located in the eastern Pyrenees mountains and bordered by Spain and France. It is the sixth smallest nation in Europe having an area of...
, Austria, and parts of France. 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 and nearby Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
through central and eastern France to Andorra.
Description and genetics
These are small snails, with a nearly cylindrical shell measuring just over 2 mm in length. There is little morphologicalMorphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
and almost no genetic variation between the supposed "species". Thus, even though the proposed synonymy resulted from mtDNA COI
Cytochrome c oxidase
The enzyme cytochrome c oxidase or Complex IV is a large transmembrane protein complex found in bacteria and the mitochondrion.It is the last enzyme in the respiratory electron transport chain of mitochondria located in the mitochondrial membrane...
and nDNA ITS1
Internal transcribed spacer
ITS refers to a piece of non-functional RNA situated between structural ribosomal RNAs on a common precursor transcript. Read from 5' to 3', this polycistronic rRNA precursor transcript contains the 5' external transcribed sequence , 18S rRNA, ITS1, 5.8S rRNA, ITS2, 28S rRNA and finally the 3'ETS...
sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
data analyses applied to the phylogenetic species concept (which does not recognize subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
), as opposed to the morphologically diverse Bythinella bicarinata
Bythinella bicarinata
Bythinella bicarinata is a species of very small freshwater snail, an aquatic gastropod mollusk in the family Amnicolidae.- Shell description :...
it might not even be warranted to accept the formerly distinct taxa as subspecies.
Conservation status
The northeastern specimens formerly separated in Bythinella compressa were classified as VulnerableVulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
(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.