Miljö: miljö / Klimatzon / djupintervall / distributionsområde
Ekologi
marina; sötvatten; brackvatten bottenlevande; anadrom (Ref. 117880). Subtropical
Asia: China, endemic to the Yangtze River and its tributaries.
Storlek / Vikt / Ålder
Könsmognad: Lm ? range ? - ? cm
Max length : 300 cm TL hane/ej könsbestämd; (Ref. 28581); publicerad maxvikt: 300.0 kg (Ref. 28581)
Kort beskrivning
Bestämningsnycklar | Morfologi | Morfometri
Head very long, snout extraordinarily long, pointed and paddle-like and base broad; mouth very large.
Body shape (shape guide): elongated.
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)
Status på IUCN:s rödlista (Ref. 130435: Version 2025-2 (Global))
Hot mot människor
Harmless
Mänskliga användningsområden
Fiskeri: kommersiell
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Uppskattningar baserade på modeller
Index för fylogenetisk mångfald (Ref.
82804): PD
50 = 1.2500 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00501 (0.00195 - 0.01287), b=3.10 (2.88 - 3.32), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Trofisk nivå (Ref.
69278): 4.2 ±0.73 se; based on food items.
Resiliens (Ref.
120179): Låg, lägsta populationsfördubblingstid 4,5-14 år (tm=5-15).
Sårbarhet i fisket (Ref.
59153): Very high vulnerability (90 of 100).
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