hemdurgan vs orange roughy

hemdurgan

noun
  • Rose fish (Sebastes norvegicus). 

orange roughy

noun
  • An edible deep-sea fish, Hoplostethus atlanticus, belonging to the slimehead family (Trachichthyidae). 

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