coalfish vs crevalle

coalfish

noun
  • any of several blackish fish, especially Pollachius virens, a pollack, and Anoplopoma fimbria, sablefish. 

crevalle

noun
  • A fish, the pompano (Trachinotus carolinus). 

  • A fish, the cavally or jurel. 

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