Kaluga Sturgeon (Huso dauricus)
Did You Know?
|Weight:||up to 2,200 pounds (1,000 kg)|
|Length:||up to 18.5 feet (5.5 m)|
|Appearance:||gray-green to black backs with a yellowish green-white belly; they have 5 major rows of "scutes"|
|Lifespan:||at least 20 years|
|Diet:||invertebrates and fishes|
|Behavior:||they migrate upriver in spring in spawn|
Kaluga sturgeon are one of the world's largest freshwater fishes--they can grow as long a 18.5 feet (5.5 m) and weigh up to 2,200 pounds (1,000 kg). They have gray-green to black backs with a yellowish green-white belly. They have five major rows of dermal scutes.
Juveniles feed on invertebrates for the first few years, but then they feed on fish. Kaluga sturgeon eat fish more than most other sturgeons. They have a crescent-shaped mouth with flat barbels to help them gulp down fish. However, Kaluga sturgeon do not feed during winter.
Spawning occurs from May-July at water temperatures of 70°F (12-20°C), over pebble deposits in calm waters of the main riverbed, in depths of 6-10 feet (2-3 m). They begin to migrate downstream almost immediately after hatching. Young enter the Sea of Okhotsk during the summer.
Historically, Kaluga sturgeon inhabited the lower two-thirds of the Amur River, from its estuary to its uppermost sections and tributaries, including these rivers:
- 595 tons in 1881
- 61 tons in 1948
- 89 tons in 1996
Since 2000, Kaluga sturgeon older than 10 years have not been observed in the Amur River channel during non-spawning periods, suggesting that adults from the resident stocks in the Amur River are absent.
- overfishing led to widespread declines in Kaluga sturgeon abundance
- commercial and recreational fishing occurred since the 1800s but is now generally banned
Current threats include:
- "bycatch" of sturgeon in fisheries targeting other species and poaching
- habitat degradation and loss from various human activities
- planned dams
- pollution and poor water quality
- competition from introduced or hybrid sturgeon
Although there are no known diseases threatening Kaluga sturgeon populations, there is concern that diseases could be introduced through aquaculture operations for other sturgeon species.
Kaluga sturgeon are listed in Appendix II of CITES, which regulates international trade.
Russia and China have stocking programs, but no reproduction of stocked fish has been confirmed.
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