Sturgeon is the common name used for some 26 species of fish in the family Acipenseridae. Sturgeon is sometimes used more exclusively to refer to the species in the two best known genera; Acipenser and Huso.
In Russia, sturgeon fisheries are of immense value. Early in summer the fish migrate into the rivers or towards the shores of freshwater lakes in large shoals for breeding purposes. The ova are very small, and so numerous that one female has been calculated to produce about three million in one season. Sturgeon can live for more than 100 years.
In countries like England, where few sturgeons are caught, sturgeon is included as a royal fish in an act of King Edward II, although it probably only rarely graces the royal table of the present period, or even that of the lord mayor of London, who can claim all sturgeons caught in the Thames above London Bridge. Where sturgeons are caught in large quantities, as on the rivers of southern Russia and on the great lakes of North America, their flesh is dried, smoked or salted. The ovaries, which are of large size, are prepared for caviar, for this purpose they are beaten with switches, and then pressed through sieves, leaving the membranous and fibrous tissues in the sieve, whilst the eggs are collected in a tub. The quantity of salt added to them before they are finally packed varies with the season, scarcely any being used at the beginning of winter. Finally, one of the best sorts of isinglass is manufactured from the airbladder. After it has been carefully removed from the body, it is washed in hot water, and cut open in its whole length, to separate the inner membrane, which has a soft consistency, and contains 70% of glutin.