''Salmo peristericus'', or the Prespa troutKoutseri I et al. (2010
Species Action Plan for the Endemic Prespa Trout, ''Salmo peristericus'': A Conservation Tool
www.balwois.com is a variety of

trout Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', '' Salmo'' and '' Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-sa ...

, a freshwater fish in the family

Salmonidae Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefish ...

. It 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 els ...

to the

Lake Prespa The Lake Prespa is located on the tripoint of North Macedonia, Albania, and Greece. It is a system of two lakes separated by an isthmus: the Great Prespa Lake, divided between the three countries, and the Little Prespa Lake, mostly within Greec ...

watershed at the border area of

Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders wit ...

and

North Macedonia North Macedonia, ; sq, Maqedonia e Veriut, (Macedonia before February 2019), officially the Republic of North Macedonia,, is a country in Southeast Europe. It gained independence in 1991 as one of the successor states of Socialist Feder ...

. Four populations are known: one in the Agios Germanos stream in northwestern Greece, and the others in the Brajcinska and Kranska rivers and the Leva Reka stream of North Macedonia. The Prespa trout is morphologically difficult to separate from other trouts of the region. Genetic data show it is close to and derived from the Adriatic lineage of

brown trout The brown trout (''Salmo trutta'') is a European species of salmonid fish that has been widely introduced into suitable environments globally. It includes purely freshwater populations, referred to as the riverine ecotype, ''Salmo trutta'' morp ...

, and do not support a distinct species status.Snoj A et al (2009
Genetic architecture of trout from Albania as revealed by mtDNA control region variation
''Genetics Selection Evolution'', 41:22 Nevertheless, its protection as an

Evolutionary Significant Unit An evolutionarily significant unit (ESU) is a population of organisms that is considered distinct for purposes of conservation. Delineating ESUs is important when considering conservation action. This term can apply to any species, subspecies, ...

is justified regardless of the taxonomic status.

References

peristericus Fish described in 1938 Taxa named by Stanko Karaman Taxonomy articles created by Polbot {{Salmoniformes-stub