The Collaborative International Dictionary of English v.0.48:

Robalo \Rob"a*lo\, n. [Sp. r['o]balo.]
   Any of several pikelike marine fishes of the West Indies and
   tropical America constituting the family Oxylabracidae,
   esp. the largest species (Oxylabrax undecimalis, syn.
   Centropomus undecimalis), a valuable food fish called also
   snook, the smaller species being called