The Collaborative International Dictionary of English v.0.48:

Bonaci \Bo`na*ci"\, n. [Amer. Sp. bonas['i], prob. from native
   name.] (Zool.)
   (a) A large grouper (Mycteroperca bonaci) of Florida and
       the West Indies, valuable as a food fish; -- called also
       aguaji and, in Florida, black grouper.
   (b) Also, any one of several other similar fishes.
       [Webster 1913 Suppl.]