crawbob vs ghost nipper

crawbob

noun
  • An Australian species of freshwater crayfish, Cherax destructor; a yabby. 

ghost nipper

noun
  • A marine yabby; a species of marine ghost shrimp, Trypaea australiensis, widely harvested by recreational anglers as bait. 

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