Biology
provided by Arkive
This nocturnal fish undertakes regular migrations, and after becoming sexually mature at seven to eight years old, it swims upstream during the spring floods each year to spawn. A large number of sticky eggs are produced, which adhere securely to stones on the riverbed (4). From hatching to around three weeks old, the tiny juveniles remain close to the river bottom, feeding on zooplankton and hiding from predators. Once they reach 10 to 11 weeks old, they are large enough to migrate downstream to join the adults (5). Older Yangtze sturgeon consume small fish and aquatic plants (4).
Conservation
provided by Arkive
Conservation of this fish is now urgent, with emphasis needed on habitat protection, capture control and stock replenishment. This sturgeon species spawns earlier in life than most sturgeons, and therefore has aquaculture potential for caviar production. Controlled production of the Yangtze sturgeon could both reduce fishing levels and allow reintroductions of fish back into the river (2).
Description
provided by Arkive
A prehistoric-looking fish, the Yangtze sturgeon has a long and slender body covered with rough skin and bony plates. A pointed snout extends from the triangular head and two pairs of barbels hang from the lower jaw. The upper side of the body varies from dark yellow through brown to dark grey, and this fades to milky white on the underside (4). Juveniles have a black body and tail with a light grey line running from head to tail (5).
Habitat
provided by Arkive
The Yangtze sturgeon is found in a variety of freshwater habitats, away from the riverbank in water eight to ten metres deep. Adults appear to prefer regions with a sandy silt bottom, and young stay in sandy shallows (4).
Range
provided by Arkive
Endemic to the Yangtze River, China (1).
Status
provided by Arkive
The Yangtze sturgeon is classified as Critically Endangered (CR) on the IUCN Red List 2007 (1), and is listed on Appendix II of CITES (3).
Threats
provided by Arkive
The Yangtze sturgeon is at risk from over-fishing, pollution, and habitat degradation and loss. An important factor in its decline was the construction of the Gezhouba Dam across the Yangtze River at Yichang in Hubei Province in 1981. As this prevented upstream migration necessary for spawning, the Yangtze sturgeon is now only found above the dam (2).
Endemic Range/ Yangtze River Basin
provided by EOL authors
Acipenser dabryanus is an endangered demersal fish found in portions of the Yangtze River Basin, previously inhabitating even greater extents of the basin. The upper Yangtze basin is considered the part from the headwaters to the Three Gorges area, or a catchment area of approximately one million square kilometers; this upper basin is quite mountainous. The upper Yangtze basin consists chiefly of Paleozoic limestone and terrigenous sedimentary rock, with some granitic material. The highest elevation ecoregion of the Yangtze Basin is the uppermost reach or headwaters catchment area of the Yangtze, known as the Tibetan Plateau alpine shrub and meadows. The most downstream element of the upper Yangtze basin is often termed the Sichuan Basin; here the Yangtze cuts through Triassic and Permian material before entering the Three Gorges. The Three Gorges area is a stretch of the Yangtze that runs approximately 660 kilometers, terminating at the site of the Three Gorges Dam. Construction of this dam without adequate biotic mitigation has resulted in considerable aquatic habitat degradation and decline of native fish populations. The demersal fish Silurus meridionalis also is found as a middle reach Yangtze River endemic species. Some of the notably large native demersal fish occurring in the Yangtze Basin are the 120 centimeter (cm) long Chinese sturgeon (Acipenser sinensis), the 200 cm Giant mottled eel (Anguilla marmorata), the 122 cm black carp (Mylopharyngodon piceus) and the 300 cm Chinese paddlefish (Psephurus gladius), and the 100 cm Silurus meridionalis.
- bibliographic citation
- C.Michael Hogan. 2012. Yangtze River. Encyclopedia of Earth. Topic ed. Peter Saundry. Ed.-in-chief Cutler J.Cleveland. National Council for Science and the Environment. Washington DC
- author
- C. Michael Hogan (cmichaelhogan)
Benefits
provided by FAO species catalogs
The native population sharply declined in the last two decades, but this species is easily propagated and has excellent commercial aquaculture potential (Wei et al., 1997).
Brief Summary
provided by FAO species catalogs
Prefers sublitoral areas, 10-20 m from the riverbank, with water depths of 8-10 m.Sandy silt ground, and abundance of detritus and benthic organisms.Young individuals often stay in sandy shallows, frequently in stretches between Luzhou and Jiangjing.Dabry's sturgeon is a potamodromous species.More active at nigth than during the day. Young fish feed almost on zooplancton and oligochaetes. Older individuals eat mainly oligochaetes and small fishes, such as gobiids, as well as chironomids, odonates and aquatic plants. Males start to mature at 4 years, and all are mature by 7 years of age. Females do not mature until at 6 years of age and all are mature by 8 years. It swim upstream for spawning during spring floods. Spawning occurs mainly in the spring, probably above Yibin. The eggs are sticky and firmly adhere to stones (Zhuang et al. 1997)
Size
provided by FAO species catalogs
More than 130 cm , and a weight of more than 16 Kg.
Distribution
provided by FAO species catalogs
Restricted to the Yangtze River system. At present, the Dabry's sturgeon is mainly distributed in the upper main stream of this river, as it passes throught the Sichuang province, and also in its major tributaries.
Diagnostic Description
provided by FAO species catalogs
Spiracle present. Snout and caudal peduncle subconical. Gill membranes joined to isthmus. Mouth transverse. 32-55 gill rakers. D:44-57, A:25-36 rays. 8-13 dorsal scutes; 26-39 lateral scutes; 9-13 ventral scutes. The body of young Dabry's sturgeon is very rough because of many bony plates on the skin (Zhuang et al., 1997). The body colour above the lateral row of scutes, is dark gray, brown gray, or yellow gray; the rest of the body is milky white. In young individuals, the lateral row of scutes is a distinct demarcation line.
- Artyukhin, E. N. - 1995. On biogeography and relationships within the genus Acipenser. The Sturgeon Quart. v. 3 (no. 2): 6-8.
- Bemis, W. E., E. K. Findeis & L. Grande. - 1997. An overview of Acipenseriformes. Environ. Biol. Fishes. 48: 25-71.
- Wei, Q., F. Ke, J. Zhang, P. Zhuang, J. Luo, R. Zhou & W. Yang. - 1997. Biology, fisheries, and conservation of sturgeons and paddlefish in China. Environm. Biol. Fish. 48: 241-255.
- Zhuang, P., F. Ke, Q. Wei, X. He & Y. Cen. - 1997. Biology and life history of Dabry's sturgeon, Acipenser dabryanus, in the Yangtze River. Environm. Biol. Fish. 48: 257-264.
Trophic Strategy
provided by Fishbase
Inhabits the middle and lower reaches of rivers.
- Recorder
- Grace Tolentino Pablico
Morphology
provided by Fishbase
Dorsal spines (total): 0; Dorsal soft rays (total): 40 - 49; Analspines: 0; Analsoft rays: 27 - 30
Migration
provided by Fishbase
Anadromous. Fish that ascend rivers to spawn, as salmon and hilsa do. Sub-division of diadromous. Migrations should be cyclical and predictable and cover more than 100 km.
Diagnostic Description
provided by Fishbase
Snout short and pointed; lips with small papilla; barbels 2 pairs and situated in belly of snout; body covered with 5 rows of ganoid scales and skin between scales rough (Ref. 45563).
Importance
provided by Fishbase
fisheries: commercial
Dabry's sturgeon
provided by wikipedia EN
Dabry's sturgeon (Acipenser dabryanus), also known as the Yangtze sturgeon, Chiangjiang sturgeon and river sturgeon, is a species of fish in the sturgeon family, Acipenseridae.[5] It is endemic to China and today restricted to the Yangtze River basin,[1] but was also recorded from the Yellow River basin in the past.[6][7] It was a food fish of commercial importance. Its populations declined drastically, and since 1988, it was designated an endangered species on the Chinese Red List in Category I and commercial harvest was banned.[5][1] It has been officially declared extinct in the wild by the IUCN as of July 21, 2022. [1]
Appearance
This sturgeon has been known to reach 2.5 m (8.2 ft) in length, but it is usually much smaller.[8] Its body is blue-gray above and yellowish white on the belly, with five rows of scutes. The head is triangular and the snout is long with the mouth located on the underside. There are two pairs of barbels.[9]
Behavior
The fish lives in slow-moving river waters over substrates of sand and mud. It feeds on aquatic plants, invertebrates, and small fish. This species is potamodromous, taking part in a migration, but never leaving fresh water.[9] It spawns in the upper Yangtze, mainly during March and April, and sometimes around November and December. Males spawn each year, but most females do not. The female produces 57,000 to 102,000 eggs.[9]
Conservation status
This was once a common fish in the Yangtze system.[9] It was known from the main river and some of its larger tributaries, as well as some lakes attached to the system. By the late 20th century, it was extirpated from the lower river and limited to the upper reaches in Sichuan. The main causes of its drastic decline include overfishing, including the overharvesting of juveniles. The construction of dams, notably the Gezhouba Dam and Three Gorges Dam, blocked the movement of the fish along the river, restricting it to the upper reaches. It also caused habitat fragmentation and degradation. Increased development and deforestation on land near the river has increased pollution from wastewater and runoff.[1] The Yangtze basin is and was its main range, but it has also been found in the Yellow River basin, with the last records in the 1960s.[6][7]
The fish has been bred in captivity since the 1970s. Thousands of individuals have been released into the Yangtze basin, but are apparently not breeding. Nevertheless, this restocking may be the only effort preventing the extinction of the species.[1]
See also
References
-
^ a b c d e f Qiwei, W. (2022). "Acipenser dabryanus". IUCN Red List of Threatened Species. 2022: e.T231A61462199. doi:10.2305/IUCN.UK.2022-1.RLTS.T231A61462199.en. Retrieved 21 July 2021.
-
^ "Appendices | CITES". cites.org. Geneva, Switzerland: CITES Secretariat. Archived from the original on 5 December 2017.
-
^ Froese, R.; Pauly, D. (2017). "Acipenseridae". FishBase version (02/2017). Retrieved 18 May 2017.
-
^ "Acipenseridae" (PDF). Deeplyfish- fishes of the world. Retrieved 18 May 2017.
-
^ a b Zhuang, P., et al. (1997). Biology and life history of Dabry's sturgeon, Acipenser dabryanus, in the Yangtze River. Environmental Biology of Fishes 48(1-4), 257-64.
-
^ a b Xie, J.Y.; W.J. Tang; Y.H. Yang (2018). "Fish assemblage changes over half a century in the Yellow River, China". Ecology and Evolution. 8 (8): 4173–4182. doi:10.1002/ece3.3890. PMC 5916296. PMID 29721289.
-
^ a b Li, S.Z. (2015). Fishes of the Yellow River and Beyond. The Sueichan Press. pp. 56–60. ISBN 9789578596771.
-
^ Froese, R. and D. Pauly. (Eds.) Acipenser dabryanus. FishBase. 2011.
-
^ a b c d Gao, X., et al. (2009). Threatened fishes of the world: Acipenser dabryanus Duméril, 1869. Environmental Biology of Fishes 85(2), 117-18.
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- copyright
- Wikipedia authors and editors
Dabry's sturgeon: Brief Summary
provided by wikipedia EN
Dabry's sturgeon (Acipenser dabryanus), also known as the Yangtze sturgeon, Chiangjiang sturgeon and river sturgeon, is a species of fish in the sturgeon family, Acipenseridae. It is endemic to China and today restricted to the Yangtze River basin, but was also recorded from the Yellow River basin in the past. It was a food fish of commercial importance. Its populations declined drastically, and since 1988, it was designated an endangered species on the Chinese Red List in Category I and commercial harvest was banned. It has been officially declared extinct in the wild by the IUCN as of July 21, 2022.
- license
- cc-by-sa-3.0
- copyright
- Wikipedia authors and editors
