twaite vs twaite shad

twaite

noun
  • A fish, the twaite shad, Alosa fallax 

twaite shad

noun
  • A fish in the herring family Clupeidae, Alosa fallax, found in the eastern Atlantic Ocean and the Mediterranean Sea. 

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