The Collaborative International Dictionary of English v.0.48:

Caribe \Ca*ri"be\, n. [Sp. a cannibal.] (Zool).
   A south American fresh water fish of the genus Serrasalmo
   of many species, remarkable for its voracity. When numerous
   they attack man or beast, often with fatal results.
   [1913 Webster]

WordNet (r) 3.0 (2006):

caribe
    n 1: small voraciously carnivorous freshwater fishes of South
         America that attack and destroy living animals [syn:
         piranha, pirana, caribe]