Environment: milieu / climate zone / depth range / distribution range
البيئة
بحري; المياه العذبة; مياه مخلوطة القاع; أسماك صاعدة (Ref. 117880). Subtropical
Asia: China, endemic to the Yangtze River and its tributaries.
الحجم / وزن / العمر
Maturity: Lm ? range ? - ? cm
Max length : 300 cm TL ذكر/ مختلط الجنس; (Ref. 28581); أعلا وزن تم نشرة: 300.0 kg (Ref. 28581)
Head very long, snout extraordinarily long, pointed and paddle-like and base broad; mouth very large.
This species is considered anadromous for it spends at least part of its life in the sea and migrates upriver to reproduce. It occurs in broad surfaced main streams of large rivers, usually staying in the middle and lower layers of the water column and occasionally swims into large lakes. Spawning period is in March and April with spawning sites located in the upper reaches of the Changjiang River but was also reported to take place in the lower Jinsha River between Shuifu and Yibin (Ref. 117880). It grows to 3 m in length and 300 kg in weight (Ref. 28581). Reported length of 7 m SL (Ref. 6866) and 500 kg weight (Ref. 4537, 58490) are doubtful (Paxton, pers. comm.). Piscivorous throughout most of its life. Threatened due to over harvesting and habitat loss (Ref. 58490). Expected number of mature individuals in the wild, less than 50, but more extensive surveys are needed across its range to confirm its existence; last seen in 2003 (Ref. 117880).
Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea and W.B. Scott, 1991. World fishes important to North Americans. Exclusive of species from the continental waters of the United States and Canada. Am. Fish. Soc. Spec. Publ. (21):243 p. (Ref. 4537)
IUCN Red List Status (Ref. 130435)
استخدامات بشرية
مصائد: تجاري
أدوات
تقارير خاصة
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مصادر علي الأنترنت
Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 1.2500 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00501 (0.00192 - 0.01311), b=3.10 (2.88 - 3.32), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
مستوى غذائي (Ref.
69278): 4.2 ±0.73 se; based on food items.
المرونه (Ref.
120179): منخفض, الحد الزمني الأدني لتضاعف عدد أفراد المجتمع 4.5-14 سنة (tm=5-15).
Fishing Vulnerability (Ref.
59153): Very high vulnerability (90 of 100).
