Schraetzer
{{Short description|Species of fish}}
{{Speciesbox
| image = Schraetzer.png
| status = LC
| status_system = IUCN3.1
| taxon = Gymnocephalus schraetser
| authority = (Linnaeus, 1758)
| synonyms = {{hidden begin|title = List}}
- Perca schraetser Linnaeus, 1758
- Acerina schraetser (Linnaeus, 1758)
- Schraitser ratisbonensium J. C. Schaeffer, 1761
- Perca danubiensis Gronow, 1854
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The schraetzer (Gymnocephalus schraetser), or striped ruffe, is a species of freshwater ray-finned fish belonging to the family Percidae, the perches and related fishes. This species is found in the catchment of the Danube river in Europe.
Taxonomy
The schraetzer was first formally described as Perca schraetser by Carl Linnaeus in the 10th edition of Systema Naturaepublished in 1758 with "southern Europe" given as the type locality.{{Cof genus|genus=Gymnocephalus|access-date=21 April 2025}}M10th edition of Systema Naturae This taxon is now considered to be a valid species within the genus Gymnocephalus, the ruffes, within the subfamily Percinae in the family Percidae.{{Cof family|family=Percidae|access-date=21 April 2025}}
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, schraetser, is derived from vernacular names for this fish in Bavaria.{{cite web |url=https://etyfish.org/leuciscinae/ |title=Order PERCIFORMES (part 6): Suborder PERCOIDEI: Families NIPHONIDAE, PERCIDAE and TRACHINIDAE|author=Christopher Scharpf |date=1 November 2024 |access-date=21 April 2025 |work=The ETYFish Project Fish Name Etymology Database |publisher=Christopher Scharpf}}
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. 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 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 {{convert|30|cm|in}} TL though most only grow to {{convert|15|cm|in}}. The greatest recorded weight for this species is {{convert|250|g|oz}}.
Utilisation
The schraetzer is of no interest to commercial fisheries, it is popular as a game fish and is also frequently used as bait in pursuit of other species.{{FishBase |genus= Gymnocephalus|species= schraetser| month = April | year = 2014}}