Bicuda and other Pike-like Characins
The bicuda/argulha (Boulengerella spp.) is an agressive, fast water fish that can be found in many of the waters holding the previously-mentioned glamor species. A high-gradient river species, Boulengerella cuvieri can reach sizes of over 15-pounds and is a powerful, acrobatic fighter. Once hooked, they launch themselves into the air, rattling their gills and throwing hooks in a fashion that would make a tarpon jealous. Larger specimens are found in the fast water Rio Travessão of northern Brazil.
Picúa/cachorro/joel (Acestrorhynchus falcatus) looks like a freshwater barracuda. They are often encountered in small packs terrorizing schools of baitfish. These fish don't grow very big (3-pounds maximum), but they're extremely aggressive, plentiful and hard fighting on light conventional rods or a 5-6-weight fly rod.