Beluga, osetra and sevruga caviar come from which fish?

Traditionally, the term caviar refers only to roe from wild sturgeon in the Caspian Sea and Black Sea (Beluga, Ossetra and Sevruga caviars). Depending on the country, caviar may also be used to describe the roe of other fish such as salmon, steelhead, trout, lumpfish, whitefish, carp, and other species of sturgeon.