butterfish vs mulloway

butterfish

noun
  • A rock gunnel, Pholis gunnellus, an eel-like fish found in the intertidal and subtidal zones of the North Atlantic. 

  • Perciform fish of the family Stromateidae, including the genera Pampus, Peprilus and Stromateus. 

  • The New Zealand fish Odax pullus, also known as greenbone. 

  • The sablefish (Anoplopoma fimbria) (the sablefish is not a true butterfish; but is called such informally) 

mulloway

noun
  • Any of the species Argyrosomus japonicus of large fish, found along the eastern coast of Africa and the coasts of Australia, prized for sport. 

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