Common names from other countries
Environment: milieu / climate zone / depth range / distribution range
البيئة
; المياه العذبة; مياه مخلوطة القاع; pH range: 7.0 - 7.5; dH range: ? - 20; سمكة نهرية (Ref. 57765); نطاق العمق 0 - 200 m (Ref. 57765), usually 1 - 8 m (Ref. 57765). Temperate; 1°C - 19°C (Ref. 57765); 74°N - 46°N, 64°E - 162°E
Asia: Siberia, rivers Ob, Irtysh, Yenisei, Lena, Kolyma, Khatanga, Pyasina, Anabar, Olenyok, Yana and Lake Baikal (Ref. 57765). Non-migratory populations exist in all river systems (Ref. 57765).
Length at first maturity / الحجم / وزن / العمر
Maturity: Lm 95.5, range 65 - 167 cm
Max length : 200 cm TL ذكر/ مختلط الجنس; (Ref. 40476); أعلا وزن تم نشرة: 210.0 kg (Ref. 59043); العمر: 63 سنين (Ref. 57765)
Extended snouts; four barbels in front of the mouth (Ref. 4639). The back is light grey to dark brown colored. The belly color varies from white to clear yellow. Five row s of scutes: 10-19D, 32-59L, 7-16V. Small star-like scutes between the main ones. Clearly slit inferior lip (Ref. 40476).
Found in deep and shallow parts of rivers, with moderate to swift current usually at depths of 1 to 8 m (Ref. 57765). Adults live essentially in freshwater although some fish frequently occur in estuaries. Males are sexually mature between 9 and 29 years; females between 9 and 34 years (Ref. 57765). Spawn in main river channel over stone-gravel or gravel-sand bottom and with strong current (Ref. 59043).
Potamodromous species (Ref. 57765). In a natural environment, males reach sexual maturity at 9-1 5 years of age and females at 16-20 years (in water recirculation systems, sexual maturity can first occur at 5 years). Spawning happens in the summer and generally every two years. Membranes on eggs become increasingly more sticky after fertilization and this allows them to stick to the substratum. This can become a problem in nurseries, but it is solved by washing the eggs in clay or diatomaceous earth suspensions. Caviar (not fecundated ovocites ) can be over 1 0% of the corporal weight of a mature female. Incubation
lasts about 1 6 days (at 10-1 5°). Larval development lasts about 20 days (at 18°). Egg size 3.0-3.6 mm, larval length at hatching 10-12 mm.
Baillie, J. and B. Groombridge (eds.), 1996. 1996 IUCN red list of threatened animals. IUCN, Gland, Switzerland. 378 p. (Ref. 12255)
IUCN Red List Status (Ref. 130435)
استخدامات بشرية
مصائد: ذو قيمة تاجرية عالية; الأستزراع المائي: تجاري; حوض مائي: احواض مائية عامة
أدوات
تقارير خاصة
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مصادر علي الأنترنت
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00269 (0.00156 - 0.00465), b=3.26 (3.12 - 3.40), in cm Total Length, based on LWR estimates for this species & Genus-body shape (Ref.
93245).
مستوى غذائي (Ref.
69278): 3.3 ±0.2 se; based on diet studies.
المرونه (Ref.
120179): منخفظ جدا, الحد الزمني الأدني لتضاعف عدد أفراد المجتمع أكثر من 14 سنة (tm=7-34; tmax=63; Fec=16,500-420,000; K=0.03).
Fishing Vulnerability (Ref.
59153): Very high vulnerability (87 of 100).
