gunnel vs sablefish

gunnel

noun
  • A small eel-shaped marine fish of the family Pholidae, especially Pholis gunnellus. 

sablefish

noun
  • A dark-coloured marine fish, Anoplopoma fimbria, of North American Pacific waters. 

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