Environment: milieu / climate zone / depth range / distribution range
; المياه العذبة; مياه مخلوطة محيطي; سمكة نهرية (Ref. 51243); نطاق العمق 2 - 30 m (Ref. 30578), usually 2 - 3 m (Ref. 27368). Temperate; 6°C - 22°C (Ref. 2059); 67°N - 36°N, 1°W - 75°E
Europe and Asia: Caspian, Baltic, Black and Aral Sea basins; Elbe (North Sea basin) and Maritza (Aegean basin) drainages. North to about 65° N in Finland. Introduced widely (Ref. 59043). Several countries report adverse ecological impact after introduction (Ref. 1739).
Length at first maturity / الحجم / وزن / العمر
Maturity: Lm 36.7, range 28 - 46 cm
Max length : 100.0 cm SL ذكر/ مختلط الجنس; (Ref. 59043); common length : 50.0 cm TL ذكر/ مختلط الجنس; (Ref. 556); أعلا وزن تم نشرة: 20.0 kg (Ref. 40476); العمر: 17 سنين (Ref. 59043)
الأشواك الظهرية (المجموع): 13 - 20; الأشعة الظهرية الناعمة (المجموع): 18-24; شوكة شرجية 2-3; أشعه شرجية لينه: 10 - 14; فقرات: 45 - 47. Distinguished from congeners in Europe by the following combination of characters: 1-2 enlarged canine teeth in anterior part of each jaw; second dorsal fin with 18-22½ branched rays; and 80-97 scales on lateral line (Ref. 59043).
Adults inhabit large, turbid rivers and eutrophic lakes, brackish coastal lakes and estuaries. Feed mainly on gregarious, pelagic fishes. They attain first sexual maturity at 3-10 years of age, usually at 4. Undertake short spawning migrations. Individuals foraging in brackish water move to freshwater habitats. Migrations up to 250 km have been recorded. Homing is well developed, even nearby populations may be relatively isolated. Spawn in pairs at dawn or night. Spawning occurs in April-May, exceptional from late February until July, depending on latitude and altitude when temperatures reach 10-14° C on spawning grounds (Ref. 59043). Popularly fished by sport fishers. Its flesh is succulent (Ref. 30578). Utilized fresh or frozen and eaten steamed, broiled and microwaved (Ref. 9988). An individual weighing 19 kg was reportedly caught in 1959 in Starnberger, Bavaria, Germany (Peter Admicka, pers. Comm. E-mail: firstname.lastname@example.org).
The spawning places are over gravel in moving water (Ref. 205). "Males are territorial and excavate shallow depressions about 50 cm in diameter and 5-10 cm deep in sand or gravel, or among exposed plant roots on which eggs are deposited, usually in turbid water and at 1-3 m depth. Spawn in pairs, at dawn or night. The female remains over the nest while the male circles rapidly around, at about 1 meter from the nest. Then male takes a vertical orientation and both swim around swiftly, and eggs and sperm are released, The female leaves the nest after all eggs are released. The male defends the nest and fans the eggs with his pectorals. Females spawn once a year, laying all the eggs at one time (Ref. 88075). Feeding larvae are positively phototactic and feed on pelagic organisms after they leave the nest for open water" (Ref. 59043).
Kottelat, M. and J. Freyhof, 2007. Handbook of European freshwater fishes. Publications Kottelat, Cornol and Freyhof, Berlin. 646 pp. (Ref. 59043)
IUCN Red List Status (Ref. 124695)
Potential pest (Ref. 57271)
مصائد: تجاري; الأستزراع المائي: تجاري; لعبة سمكه: نعم; حوض مائي: احواض مائية عامة
مصادر علي الأنترنت
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5312 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00661 (0.00546 - 0.00799), b=3.10 (3.04 - 3.16), in cm total length, based on LWR estimates for this species (Ref. 93245
مستوى غذائي (Ref. 69278
): 4.0 ±0.78 se; based on food items.
Generation time: 10.2 (6.5 - 12.9) years. Estimated as median ln(3)/K based on 21 growth studies.
المرونه (Ref. 120179
): منخفض, الحد الزمني الأدني لتضاعف عدد أفراد المجتمع 4.5-14 سنة (K=0.10-0.24; tmax=16; Fecundity=10,000).
عرضة للخطر (Ref. 59153
): High vulnerability (62 of 100) .
Nutrients (Ref. 124155
): Calcium = 45.9 [24.6, 74.4] mg/100g ; Iron = 0.316 [0.170, 0.633] mg/100g ; Protein = 18.5 [17.6, 19.4] % ; Omega3 = 1.15 [0.43, 2.88] g/100g ; Selenium = 2.14 [0.65, 6.15] μg/100g ; VitaminA = 21.1 [6.3, 72.6] μg/100g ; Zinc = 0.73 [0.52, 1.02] mg/100g (wet weight); based on nutrient studies.