| Description |
The Rio Paraná is about 4695 km long and begins at the confluence of the Rio Grande and Rio Paranaíba. From southern Brazil, it runs in a southwest direction and drains into the Río de la Plata estuary. The Rio Paraná can be divided into sections with distinct geographical and biological characteristics (Resende, 2003, cited in Ref. 74689). The Upper Paraná, which is separated by falls of Sete Quedas from the rest of the basin, has a distinct ichthyofaunal “province” (Bonetto, 1998, cited in Ref. 74689). It mostly lies within Brazil and forms the border with Paraguay at its southern end. Veering southwest, is the High Paraná which follows the contour of the Sierra de Misiones and forms the border between Paraguay and Argentina. In this area, falls are characteristically close to their confluence with the High Paraná and thus limit passage of fishes upriver. The Middle Paraná, marked by the confluence with the Rio Paraguay, runs south through Argentina as a plains river over a broad floodplain. The river flows as the Lower Paraná at the confluence with the Rio Salado in Santa Fé, (Bonetto, 1986; Resende, 2003, cited in Ref. 74689). |