beluga

noun

Etymology: Borrowed from Russian белу́га (belúga), from бе́лый (bélyj, “white”). In modern standard Russian, белу́га (belúga) denotes the fish Huso huso only, while белу́ха (belúxa) denotes the cetacean.

1. A whale, Delphinapterus leucas, found in the Arctic Ocean.
2. A fish, Huso huso, that is a source of caviar, which is found in the Black Sea and the Caspian Sea.