Insect larvae, mollusks & other small invertebrates that live in the mud
Habitat
Large freshwater lakes & rivers
Range
Northern hemisphere in Europe, Asia & North America
The sturgeons
Special sturgeons
Sturgeons have rows of bony plates covering the head and along the body. The upper lobe of its tail fin is longer than the lower. Some species are long-distance travellers, capable of making round-trip journeys of up to 3,500 kilometres a year. Sturgeons can grow to be very large, up to 4.2 metres. All sturgeon species have been extensively exploited by humans for their meat and roe. As a result, sturgeons are among the most threatened animals in the world.
A tactile search for food
Sturgeons have a toothless mouth on the underside of the snout, preceded by four sensitive whisker-like barbels. These bottom-dwellers have bad eyesight and depend on their tactile barbels to locate food. To increase the coverage area of their food search, sturgeons sometimes wag their head from side to side. Scientists believe that sturgeons may carry taste buds outside their mouths to assist them in detecting prey.
Feeding off the bottom
Once located, prey is sucked up with its mouth, like a vacuum cleaner. Usually, the prey is swallowed whole, straight into the fish’s stomach. Due to its size in comparison with that of its prey, sturgeons spend much time scouring the mud for their meals. Besides invertebrate prey, they may also feed on dead fish. They may also take live fish such as smelt, shad and sculpin in the middle of their spawning process. Some species of sturgeon thrive off clams and crayfish.
Together, we protect wildlife
Black pearl producers
Sturgeons are a highly valuable group of species – beluga sturgeon caviar (also known as black pearls) can fetch up to US$10,000 per kilogram.
This has led to over-harvesting of many sturgeon species. With sturgeon stocks depleted, fishermen are now turning to the closely-related paddlefish to meet the caviar demand.
The IUCN Status
CR
Critically Endangered
At extremely high risk of extinction in the wild
The IUCN Red List of Threatened Species
The IUCN Red List of Threatened Species is widely recognized as the most comprehensive, objective global approach for evaluating the conservation status of plant and animal species.
DD
Data Deficient
Unknown risk of extinction
LC
Least Concern
At relatively low risk of extinction
NT
Near Threatened
Likely to become vulnerable in the near future
VU
Vulnerable
At high risk of extinction in the wild
EN
Endangered
At very high risk of extinction in the wild
CR
Critically Endangered
At extremely high risk of extinction in the wild
EW
Extinct in the Wild
Survives only in captivity
EX
Extinct
No surviving individuals in the wild or in captivity