Chinese Sturgeon (Acipenser sinensis)
Did You Know?
|Weight:||up to 990 pounds (450 kg)|
|Length:||up to 16 feet (5 m)|
|Appearance:||gray-black backs with red-brown or gray sides and a white belly; they have 5 major rows of "scutes"|
|Lifespan:||at least 35 years|
|Diet:||aquatic insect larvae, small fishes, and crustaceans|
|Behavior:||they migrate upriver in summer and spawn in fall/winter|
Chinese sturgeon are "anadromous" fish. They can grow to approximately 16 feet (5 m) long and can weigh up to 990 pounds (450 kg). They are gray-black on their backs, but their sides are red-brown or gray; their bellies are white. They have five major rows of dermal scutes.
They reach sexual maturity between 8-28 years of age, with males reaching sexual maturity at 8-18 years and females at 13-28 years.
Chinese sturgeon are thought to live until at least 35 years old. They are "benthic" feeders and typically forage on invertebrates and small fishes.
They spawn in the Yangtze River. They reach the mouth of the river in June or July and then spawn and overwinter in the middle of the river between September and November. Before construction of the Gezhouba Dam in 1981, they used to migrate up to 1,860 miles (3,300 km) upriver to spawn. Now, there is just one remaining spawning ground, below the dam.
Spawning usually occurs at night in October or November, at water temperatures of 15-20°C (59-68°F), in substrates ranging from the size of coarse gravel to 20-inch (0.5 m) boulders, at depths of 25-85 feet (8-26 m), with current velocities near 3 feet per second (1 m/s).
Young sturgeon remain in the river for a year before migrating to the sea. Juveniles live in estuaries and near coastlines. Juveniles (about 3-15 inches long) are found in the Yangtze River estuary from the middle of April through early October. Then, when they become secually mature, they migrate upriver.
Historically, they were native to the northwest Pacific Ocean and found in China, Japan, South Korea, and North Korea. In China, they were found in the Yellow, Yangtze, Pearl, Mingjiang, and Qingtang Rivers.
Chinese sturgeon are thought to have declined by over 95% from about 100,000 in the 1970s to about 2,200 in the 1980s. Recent surveys (2005-2007) show the total spawning population to be only about 200-250 individuals.
Between 1983-2007, over 9 million juveniles (including larvae) were released into Yangtze River to increase population numbers, but the contribution of these releases to wild stocks is considered to be less than 10%.
- overfishing led to widespread declines in abundance
- commercial and recreational fishing occurred for hundreds of years, but is now generally banned
Current threats include:
- "bycatch" of sturgeon in fisheries targeting other species
- habitat degradation and loss from various human activities such as dredging, dams, water withdrawals, and other development
- habitat impediments, including locks and dams
- pollution and poor water quality
- small population size and low genetic variability
- competition from introduced sturgeon
Chinese sturgeon are listed in Appendix II of CITES, which regulates international trade.
In 2012, WildEarth Guardians and Friends of Animals petitioned [pdf] us to list 15 foreign sturgeon species under the ESA. We proposed to list 5 species as endangered under the ESA. (The other 10 species were determined to be under the jurisdiction of the U.S. Fish and Wildlife Service, and USFWS is reviewing their status.)
|Final Endangered Listing of Five Sturgeon Species||79 FR 31222||06/02/2014|
Proposed Endangered Listing of Five Species of Sturgeons under the ESA
|78 FR 65249||10/31/2013|
|90-day Finding on a Petition To List Five Species of Sturgeon as Threatened or Endangered under the ESA||77 FR 51767||08/27/2012|
|Petition to List 15 Sturgeon Species as Threatened or Endangered||n/a||various|
- Endangered and Threatened (ESA-listed) Sturgeon:
- Endangered and Threatened (ESA-listed) Fish
Updated: June 2, 2014