Trachurus symmetricus vs saurel

Trachurus symmetricus

saurel

noun
  • Any carangoid fish of the genus Trachurus, especially Trachurus trachurus, of Europe and America, and Trachurus picturatus of California; the skipjack, scad or horse mackerel. 

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