the basins of other tributaries and sub-tributaries of the Amazon system are unclear in this flat, flooded, and swampy area. Some tributaries of the Japurá River originate very close to the Solimões River (Auati Paraná River), and some tributaries of the Negro River arise near the Japurá (Uneiuxi, Cuiuni, and Unini rivers), with connections and bifurcations between them during flood seasons.

Although the Caquetá/Japurá is a broad and voluminous river, the existence of numerous rapids throughout its course has significantly hindered