Betta pugnax

from The Collaborative International Dictionary of English v.0.48
Fighting \Fight"ing\, a.
   1. Qualified for war; fit for battle.
      [1913 Webster]

            An host of fighting men.              --2 Chron.
                                                  xxvi. 11.
      [1913 Webster]

   2. Occupied in war; being the scene of a battle; as, a
      fighting field. --Pope.
      [1913 Webster]

   {A fighting chance}, one dependent upon the issue of a
      struggle. [Colloq.]

   {Fighting crab} (Zool.), the fiddler crab.

   {Fighting fish} (Zool.), a remarkably pugnacious East Indian
      fish ({Betta pugnax}), reared by the Siamese for
      spectacular fish fights.
      [1913 Webster]
    

[email protected]