marlin vs merlin

marlin

noun
  • Any species of game fish belonging to either of the genera Tetrapturus or Makaira. Every such species has a pointed, spear-like projection of the upper jaw. 

merlin

noun
  • A small falcon, Falco columbarius, that breeds in northern North America, Europe, and Asia. 

  • A cytoskeletal protein active in the suppression of tumors. 

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