Caviar (also: Caviar) is purified and salted roe (eggs, also: grain / pearl) of different sturgeon species caught mainly in the Black Sea, Azov Sea, the Arctic Ocean and Caspian Sea.
The most common types are the sterlet (Acipenser ruthenus) as the smallest species, the Siberian sturgeon (Acipenser baerii), the Russian sturgeon (Acipenser gueldenstaedtii) and the beluga (Huso huso), the largest species of sturgeon. Caviar is sometimes called "Black Gold".
Caviar has been mostly won by slaughter of sturgeon, as only immature eggs (also: grain / pearl) were stable enough to survive the thorough cleaning of gonadal tissue and salting. After a patent of the Alfred Wegener Institute for Polar and Marine Research caviar is made of stripped eggs without the sturgeon are killed since 2014 in what is now a controversial method.