Hucho bleekeri

Hucho bleekeri, or the Sichuan taimen, is a species of freshwater fish in the salmon family (Salmonidae), endemic to the Yangtze basin in China. Their typical habitat includes mountain streams and small rivers, typically being found in the catchment areas of the Dadu River in Sichuan and Qinghai Provinces, as well as the Hanjiang River. This particular fish population is largely threatened by habitat loss and illegal fishing, resulting in a "critically endangered" conservation status from the International Union for Conservation of Nature.

Hucho bleekeri
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Actinopterygii
Order:
Salmoniformes
Family:
Salmonidae
Genus:
Hucho
Species:
H. bleekeri
Binomial name
Hucho bleekeri
Kimura, 1934
[1]

Appearance

The vertebrates have a dark Gray back, silvery white underside, and small cross-shaped spots across the body and gill cover. Adults can grow up to 64 cm (2 ft 1 in) in length.[2]

Distribution and habitats

Sichuan taimen are endemic to the Yangtze basin in China. They are found in the upper tributaries of the Yangtze River in Sichuan Province, the upper and middle reaches of the Dadu River in Sichuan and Qinghai Provinces, and the upper reaches of the Hanjiang River south of the Qin Mountains in Shaanxi Province.[2] It dwells predominantly in fast-flowing streams with sandy and gravel substrates.[3] The species prefers mountain brooks at 700–3,300 m (2,300–10,800 ft) meters above sea level with high dissolved oxygen (>5 mg/l) and a low water temperature (less than 15 °C or 59 °F).[4]

Diet

Juveniles feed mostly on zooplankton and insects, while adults are largely piscivorous.[3]

Threats

According to the IUCN, the Sichuan taimen is threatened mostly by habitat loss from the construction of hydropower stations, erosion of soil due to deforestation, road construction, and sand excavation. Despite legal protections, the species is also threatened by illegal fishing. Recent studies have estimated the species has endured a 50-80% decline in population over the past three generations, and the decline is expected to continue. Only an estimated 2,000-2,500 mature individuals survive.[2]

See also

References
  1. Salmonid Specialist Group (Salmonid Red List Authority) 2012. Hucho bleekeri. The IUCN Red List of Threatened Species. Version 2019-1
  2. Song, Z. 2012. Hucho bleekeri. In: IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 26 October 2012.
  3. Froese, Rainer and Pauly, Daniel, eds. (2014). "Hucho bleekeri" in FishBase. April 2014 version.
  4. Hu et al. 2008. "Threatened fishes of the world: Hucho bleekeri Kimura, 1934 (Salmonidae)." Environmental Biology of Fishes 82.4: 385-386.
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