jack mackerel vs pickerel

jack mackerel

noun
  • Any of various edible fish, especially of genus Trachurus, but also genera Caranx, Acanthocybium and Euthynnus. 

pickerel

noun
  • A freshwater fish of the genus Esox. 

  • Walleye, A species of gamefish, Sander vitreus, native to the Northern U.S. and Canada with pale, reflective eyes. 

  • A wading bird, the dunlin. 

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