Río Colastiné is a river located in the Santa Fe province of Argentina, flowing through the greater Paraná Delta system in the Paraná Platense region. The river runs through a rich floodplain environment characteristic of the lower Paraná basin, with warm, productive waters that support a diverse community of native South American freshwater fish. The area around Colastiné Sur is one of the most recognized fishing destinations in the Santa Fe region, drawing anglers from the city of Santa Fe and surrounding areas. The river's connection to the broader Paraná system means it benefits from the nutrient-rich, typically turbid waters common to this part of Argentina, creating excellent conditions for a wide variety of warmwater species.