There are countless species of catfish throughout the Amazon basin (actually, over 1300).  They range in size from the diabolical candirú (Pygidiidae), a tiny parasitic catfish that lodges itself in the urethral openings of other fish or animals (or occasionally, even humans) to the monstrous piraiba (Brachyplatystoma filamentosum), which has been reported to grow over 8-feet long and weigh in excess of 350-pounds). 

Among the most pursued of the giants (above) is the brutish jau (Paulicea lutkeni).  A heavy bodied linebacker of a fish, the jau is surprisingly mobile (it is a common migrator) and agile (wait till you've got one on the end of your rod).  These bareknuckle fighters have been estimated to exceed 200 lbs. and will wear the arms off of even the most determined anglers.  They are experts at utilizing current and will lead anglers on a merry chase through rapids and waterfalls before giving you the satisfaction of bringing them to the boat. 

The aforementioned piraiba is bigger yet.  Longer, slimmer and more acrobatic than the jau, they have been known to jump; a very un-catfishlike behavior.  Imagine 7-foot of catfish launching itself into the air!  These creatures are not easy to bring to the boat.

Pirarara (Phractocephalus hemeliopteris) is an extremely husky catfish characterized by its striking black, white and red coloration.  Its strongly ossified head and forequarters allows it to dominate river bottoms with no fear of predation.  Although not an athletic performer on rod and reel, it is a tough bulldog-like fighter that doesn't quit until it's exhausted enough to have to leave the bottom. The question is , will you have enough stamina to fight it out.

Cut or whole bait, fished deep on a 14/0 circle hook is deadly for all three of these giant species.  A stout offshore rod/reel combo spooled with heavy braid is recommended. These monsters can literally tow a 16-foot  boat upstream! 

There are even several Amazonian catfish that have been known to  take a fly, including several species collectively called bagre rayado (Pseudoplatystoma sp.).  It is important to note that these catfish are nothing like our local ‘cats’ which tend to be bottom-feeding and rather lethargic.  Many of the larger species of Amazonian catfish are migratory, extremely active and aggressive predators that live in fast water and actively feed with the other previously-mentioned gamefish.  Pound for pound, these ‘cats’ are as strong – if not stronger – than any fish you'll encounter on a rod and reel.