M. gunnellus

from The Collaborative International Dictionary of English v.0.48

Gunnel \Gun"nel\, n. [See {Gunwale}.]
   1. A gunwale.
      [1913 Webster]

   2. (Zool.) A small, eel-shaped, marine fish of the genus
      {Mur[ae]noides}; esp., {M. gunnellus} of Europe and
      America; -- called also {gunnel fish}, {butterfish}, {rock
      eel}.
      [1913 Webster]