Eggs, or roe, of sturgeon preserved with salt. Most true caviar is produced in Russia and Iran, from fish taken from the Caspian and Black seas. The best grade, beluga, is prepared from large black or gray eggs; fresh beluga is relatively scarce and thus expensive. Caviar may be pasteurized for longer storage. Lesser grades are made from smaller, denser eggs. In the U.S., the roe of salmon, whitefish, lumpfish, and paddlefish is sometimes sold under the name caviar.