The eggs, or roe, of sturgeon are called caviar. Preserved with salt, caviar is usually eaten as an appetizer. 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 caviar is relatively scarce and thus expensive. Lesser grades are from smaller, denser eggs. In the U.S., the roe of salmon, whitefish, lumpfish, and paddlefish is sometimes sold under the name caviar.