The schraetzer (''Gymnocephalus schraetser''), or striped ruffe, is a species of freshwater

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Percidae The Percidae are a family of ray-finned fish, part of the order Perciformes, which are found in fresh and brackish waters of the Northern Hemisphere. The majority are Nearctic, but there are also Palearctic species. The family contains nearly 250 ...

, the

perch Perch is a common name for freshwater fish from the genus ''Perca'', which belongs to the family Percidae of the large order Perciformes. The name comes from , meaning the type species of this genus, the European perch (''P. fluviatilis'') ...

es and related fishes. This species is found in the catchment of the

Danube The Danube ( ; see also #Names and etymology, other names) is the List of rivers of Europe#Longest rivers, second-longest river in Europe, after the Volga in Russia. It flows through Central and Southeastern Europe, from the Black Forest sou ...

river in Europe.

Taxonomy

The schraetzer was first formally described as ''Perca schraetser'' by

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

in the 10th edition of ''Systema Naturae''published in 1758 with "southern Europe" given as the type locality.M10th edition of Systema Naturae This taxon is now considered to be a valid species within the genus ''

Gymnocephalus ''Gymnocephalus'' is a genus of ray-finned fishes from the family Percidae, which includes the perches, pike-perches and darters. They are from the Western Palearctic area, although one species, '' Gymnocephalus cernua'' has been accidentall ...

'', the ruffes, within the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

Percinae The Percidae are a family of ray-finned fish, part of the order Perciformes, which are found in fresh and brackish waters of the Northern Hemisphere. The majority are Nearctic, but there are also Palearctic species. The family contains nearly 250 ...

in the family Percidae.

Etymology

The schraetzer is classified within the genus ''Gymnocephalus'', a name that means "naked head", an allusion to the scaleless head of these fishes. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''schraetser'', is derived from

vernacular name Vernacular is the ordinary, informal, spoken form of language, particularly when perceived as having lower social status or less prestige than standard language, which is more codified, institutionally promoted, literary, or formal. More n ...

s for this fish in

Bavaria Bavaria, officially the Free State of Bavaria, is a States of Germany, state in the southeast of Germany. With an area of , it is the list of German states by area, largest German state by land area, comprising approximately 1/5 of the total l ...

Distributiuon and habitat

The schraetzer is endemic to the catchment of the Danube River, being found in large and medium sized rivers from the headwaters in Germany downstream to the

Danube delta The Danube Delta (, ; , ) is the second largest river delta in Europe, after the Volga Delta, and is the best preserved on the continent. Occurring where the Danube, Danube River empties into the Black Sea, most of the Danube Delta lies in Romania ...

. It is found in stretches of rivers with a moderate current and mud or sand river beds.

Biology

The schraetzer is a largely nocturnal predator, feeding on mainly molluscs, it is crepuscular and will feed in daylight too. The

spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

season runs from April to June and sexual maturity is atained after at 2 to 3 years of age. This species can reach a length of TL though most only grow to . The greatest recorded weight for this species is .

Utilisation

The schraetzer is of no interest to

commercial fisheries Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often p ...

, it is popular as a

game fish Game fish, sport fish or quarry refer to popular fish species pursued by recreational fishing, recreational fishers (typically angling, anglers), and can be freshwater fish, freshwater or saltwater fish. Game fish can be fish as food, eaten aft ...

and is also frequently used as bait in pursuit of other species.

References

{{Taxonbar, from=Q912544 Gymnocephalus Freshwater fish of Europe Fish of Europe Fish described in 1758 Taxa named by Carl Linnaeus Taxonomy articles created by Polbot Habitats Directive species