cuttlefish vs twaite shad

cuttlefish

noun
  • any of various squid-like cephalopods (marine mollusks) of the order Sepiida that have eight arms, two retractable tentacles, and a calcareous internal shell, and can eject a dark ink when threatened 

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 cuttlefish and twaite shad occurred in a corpus of books? (source: Google Ngram Viewer )