I've been into a 'Boat Hotel' during the fishing days... Once the Rio Negro was overflow, the fishing got to hard close to it, so, we just travel a full day up into a tributary river of Negro's. There, the water level was a little lower...
It's not that easy to catch monsters P. Bass, you gotta work hard and be pacient.... Tucunarés Borboletas are easily catch, around 2 - 4 kg (Believe me, 4 kg !!)
A big biodiversity, Tucunarés: Borboleta, Popoca, Açu, Paca and variations of Amarelo ... Black Arowana, Black Pirana, Pirarara, Piraíba, C. Pikes (lenticulata and red), Oscar, Wolf fish and Bicuda (Boulengerella spp)...