Rio Ivaí is one of Paraná State's most significant river systems, flowing through the heart of Brazil's southern interior before joining the Paraná River. This expansive river basin drains a large portion of central Paraná and supports a remarkably diverse fish community, with the Ivaí sub-ecoregion alone hosting 132 recorded freshwater species. The river winds through a landscape shaped by dramatic elevation changes, with numerous waterfalls and rapids in the upper reaches giving way to broader, slower stretches in the lower basin. The river's character shifts considerably from its headwaters to its confluence with the Paraná, offering anglers a wide variety of water types and fishing experiences across its length.