Striped ruff [1] ( lat. Gymnocephalus schraetser ) is a species of ray-finned fish from the perch family (Percidae).
| Striped ruff |
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| Scientific classification |
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| No rank : | Bilateral symmetrical |
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| International scientific name |
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Gymnocephalus schraetser ( Linnaeus , 1758 ) |
| Security status |
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Least ConcernedIUCN 3.1 Least Concern : 9565 |
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Body length 15-18 cm (maximum - 30 cm), weight up to 250 g. A characteristic feature is the presence of 3-4 longitudinal dark stripes on the sides. The general features of biology and the life cycle coincide with those of an ordinary ruff .
This species inhabits the Danube basin from Bavaria to the mouth, and is isolated from the Danube by the Kamcha river basin in Bulgaria. In addition, it is found in the Black Sea in the desalinated part in front of the Danube Delta. On the territory of Ukraine, striped ruff is found at the mouth of the Danube (found near the city of Izmail and in the Danube Biosphere Reserve ), as well as in the Transcarpathian region in the lower tributaries of the Tisza River.
In some places, the striped ruff is still a fairly common species, but in most of the range has become rare. Habitats - sections of rivers with clean water, a sandy bottom with an admixture of pebbles and gravel. Usually it keeps at depth in the daytime, in the shade, at night it moves to shallow rifts. The optimal pH range is 7.0-7.5; active at a water temperature of 4-18 ° C.
The main food items are small crustaceans, insect larvae, groundworms, caviar and juveniles of other fish.
Spawning occurs in April and May (earlier at the mouth of the Danube, later) fertility of females 10-12 cm long - from 65 thousand to about 100 thousand eggs. Caviar lays on a sandy rocky bottom in separate (up to three) portions.
In the first two years of life, growth is intense, later it slows down.
Striped ruff is the least worrisome species. It is listed in the IUCN Red List and the Red Book of Ukraine .
