mudfish vs spiny dogfish

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 

spiny dogfish

noun
  • Squalus acanthias, one of the best known of the dogfish which are members of the family Squalidae in the order Squaliformes 

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