''Crenobia alpina'', known as the alpine flatworm, is a species of

triclad Planarians (triclads) are free-living flatworms of the class Turbellaria, order Tricladida, which includes hundreds of species, found in freshwater, marine, and terrestrial habitats.pp 3., "Planarians (the popular name for the group as a whole ...

belonging to the family

Planariidae Planariidae is a family of freshwater planarians. The type genus is '' Planaria'' Müller, 1776.Ball IR: A contribution to the phylogeny and biogeography of the freshwater triclads (Platyhelminthes: Turbellaria). Biology of the Turbellaria (Ed ...

.Tyler, S., Artois, T.; Schilling, S.; Hooge, M.; Bush, L.F. (eds) (2006-2023). World List of turbellarian worms: Acoelomorpha, Catenulida, Rhabditophora
''Crenobia alpina'' (Dana, 1766)
Accessed 2023-06-24. They are found across the

Alps The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia. ...

Taxonomy

''Crenobia alpina'' has been considered by some to be a

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

,Brändle, M., Sauer, J., Opgenoorth, L., and Brandl, R. (2017). Genetic diversity in the Alpine flatworm ''Crenobia alpina'', Web Ecol., 17, 29–35, . with some

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 ...

of ''Crenobia alpina'' being placed as separate species within the genus ''

Crenobia ''Crenobia'' is a genus of planarians in the family Planariidae. It is endemic to Europe and Anatolia. Description The genus ''Crenobia'' includes planarians with an extremely thick muscle coat surrounding the genital atrium. The copulatory b ...

'', and others having uncertain taxonomic placement. All subspecies are found within mountainous regions of Europe, particularly the

, but have been found within mountainous areas of

Eastern Europe Eastern Europe is a subregion of the Europe, European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural and socio-economic connotations. Its eastern boundary is marked by the Ural Mountain ...

as well. Recognized subspecies include: * ''C. a. alba'' (Oye, 1935) - Central Europe, the Alps and Great Britain * ''C. a. alpina''(Dana, 1766) - Central Europe, the Alps,

Great Britain Great Britain is an island in the North Atlantic Ocean off the north-west coast of continental Europe, consisting of the countries England, Scotland, and Wales. With an area of , it is the largest of the British Isles, the List of European ...

Romania Romania is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern and Southeast Europe. It borders Ukraine to the north and east, Hungary to the west, Serbia to the southwest, Bulgaria to the south, Moldova to ...

* ''C. a. anophthalma'' (Mrazek, 1907) (sometimes considered to be a separate species, ''Crenobia anophthalma'') -

Dinaric Alps The Dinaric Alps (), also Dinarides, are a mountain range in Southern Europe, Southern and Southcentral Europe, separating the continental Balkan Peninsula from the Adriatic Sea. They stretch from Italy in the northwest through Slovenia, Croatia ...

Montenegro , image_flag = Flag of Montenegro.svg , image_coat = Coat of arms of Montenegro.svg , coa_size = 80 , national_motto = , national_anthem = () , image_map = Europe-Mont ...

Tyler, S., Artois, T.; Schilling, S.; Hooge, M.; Bush, L.F. (eds) (2006-2023). World List of turbellarian worms: Acoelomorpha, Catenulida, Rhabditophora
''Crenobia alpina anophthalma'' (Dana, 1766)
Accessed 2023-06-24. * ''C. a. bathycola'' (Steinmann, 1911) (sometimes considered to be a separate species, ''Crenobia bathycola'') -

Swiss Alps The Alps, Alpine region of Switzerland, conventionally referred to as the Swiss Alps, represents a major natural feature of the country and is, along with the Swiss Plateau and the Swiss portion of the Jura Mountains, one of its three main Physica ...

* ''C. a. corsica'' (Arndt, 1920) (sometimes considered to be a separate species, ''Crenobia corsica'') -

Corsica Corsica ( , , ; ; ) is an island in the Mediterranean Sea and one of the Regions of France, 18 regions of France. It is the List of islands in the Mediterranean#By area, fourth-largest island in the Mediterranean and lies southeast of the Metro ...

* ''C. a. meridionalis'' (Thienemann, 1938) - Northern Europe * ''C. a. montenigrina'' (Mrazek, 1904) (both this subspecies and the species '' Crenobia montenegrina'', under the same describing authority, are accepted by taxonomic databases) -

Lake Ohrid Lake Ohrid is a lake which straddles the mountainous border between the southwestern part of North Macedonia and eastern Albania. It is one of Europe's deepest and oldest lakes, with a unique aquatic ecosystem of worldwide importance, with more th ...

* ''C. a. septentrionalis'', (Thienemann, 1938) - Southern Europe,

Rügen Rügen (; Rani: ''Rȯjana'', ''Rāna''; , ) is Germany's largest island. It is located off the Pomeranian coast in the Baltic Sea and belongs to the state of Mecklenburg-Western Pomerania. The "gateway" to Rügen island is the Hanseatic ci ...

Brändle, M., Roland Heuser, Andreas Marten, & Brandl, R. (2007)
Population Structure of the Freshwater Flatworm Crenobia alpina (Dana): Old Lineages and Low Gene Flow
''Journal of Biogeography'', ''34''(7), 1183–1192. * ''C. a. teratophila'' (Steinmann, 1908) (both this subspecies and the species '' Crenobia teratophila'', under the same describing authority, are accepted by taxonomic databases)

References

Animals described in 1766 Continenticola {{Flatworm-stub