by some geologists, as they consider the Araguaia River to form two distributaries, and Bananal Island to be the landmass between these two distributed rivers. However, Bananal Island is technically an island as it does not touch the main landmass at any point.

Umananda Island, at 0.02 km², is among contenders as the smallest permanently-inhabited river island, or islet, with fixed dwellings. Umananda also lies in the Brahmaputra River.