bowfin vs mudfish

bowfin

noun
  • A voracious ganoid fish, Amia calva, the last survivor of the order Amiiformes, found in the fresh waters of the United States. 

mudfish

noun
  • Heterobranchus didorsalis (African catfish) 

  • Clarias spp., including Clarias anguillaris, Clarias gariepinus, Clarias agboyiensis, Clarias leviceps 

  • Channa striata (striped snakehead) 

  • Chrysichthys nigrodigitatus (bagrid catfish) 

  • Clarotes laticeps (widehead catfish) 

  • Protopterus annectens (West African lungfish) 

  • All species of Neochanna 

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