Also molluscs and other small invertebrates that live in the mud
Some species travel to the ocean
Also Asia and North America
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.
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.
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.