A sturgeon is a a fish in the family Acipenseridae, which contains over 20 known species. Humans are most familiar with the sturgeon because it is a famous source of caviar, unfertilized roe collected from female fish. Since 1998, many species of sturgeon have been regulated by the Convention on International Trade in Endangered Species (CITES), because of concerns about overfishing. Legally traded sturgeon products are accompanied with a CITES certificate verifying that they have been inspected and the fishery has been approved.

The physical appearance of a sturgeon is somewhat primordial. The fish are long, with several rows of bony plates along their bodies, along with an elongated snout which has protruding barbels. The fish are bottom feeders, using their wedge-like snouts to churn up the bottom of waterways for food. Most sturgeon eat mollusks, worms, and larvae. Sturgeons are classified as ganoid fishes, in a reference to the bony plates which line their bodies.

The Northern hemisphere exclusively supports sturgeon, and they prefer temperate, rather than tropical waters. Some sturgeon are anadromous, which means that they travel between salt and fresh water. Others live solely in fresh water, usually within landlocked bodies of water, and some species spend their lives at sea. The largest species is the Russian sturgeon, which can reach a length of 13 feet (almost four meters). Sturgeon of approximately half that size are much more abundant.

Humans have been eating sturgeon and their products for centuries. The caviar is the most prized sturgeon product, but the flesh is eaten as well. Sturgeon meat is rich, high in fat, and very dense with a mild flavor. When obtainable, it is eaten fresh in many parts of Europe. In Russia, where large numbers of the fish are harvested for their roe, the meat is dried or smoked before being sold. Humans also use the swim bladder of the fish to extract isinglass, a type of gelatin used to clarify foods such as beer.

As is the case with many other threatened fish species, attempts are being made to make sturgeon fishing more sustainable. In nations where the trade in caviar is an important part of life and the economy, many fisheries are working with conservationists to preserve sturgeon stocks. Public awareness campaigns have also begun to alert consumers to the problem, encouraging them to eat caviar from less threatened species, and to purchase only certified sturgeon caviar.