beluga vs hausen

beluga

noun
  • A fish found in the Caspian Sea and the Black Sea (Huso huso), that is a source of caviar. 

  • A cetacean, Delphinapterus leucas, found in the Arctic Ocean. 

hausen

noun
  • European sturgeon (Huso huso) 

How often have the words beluga and hausen occurred in a corpus of books? (source: Google Ngram Viewer )