分類 / Names
共通名の | 類義語 | Catalog of Fishes(部類, 種) | ITIS | CoL | WoRMS | Cloffa
Environment: milieu / climate zone / depth range / distribution range
生態学
海; 新鮮な水; 汽水性の 底生の; 昇流魚 (Ref. 117880). Subtropical
Asia: China, endemic to the Yangtze River and its tributaries.
サイズ / 重さ / 年齢
Maturity: Lm ? range ? - ? cm
Max length : 300 cm TL オス/雌雄の選別がない; (Ref. 28581); 最大公表体重: 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)
Human uses
水産業: 商業
用具
特記事項
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インターネットの情報源
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).
栄養段階 (Ref.
69278): 4.2 ±0.73 se; based on food items.
回復力 (Ref.
120179): 低い, ４．５年～１４年の倍増期間の最小個体群 (tm=5-15).
Fishing Vulnerability (Ref.
59153): Very high vulnerability (90 of 100).
