The Pantanal () is a natural region encompassing the world’s largest tropical wetland area. It is located mostly within the Brazilian state of Mato Grosso do Sul, but it extends into Mato Grosso and portions of Bolivia and Paraguay. It sprawls over an area estimated at between . Various subregional ecosystems exist, each with distinct hydrological, geological and ecological characteristics; up to 12 of them have been defined (RADAMBRASIL 1982). Roughly 80% of the Pantanal floodplains are submerged during the rainy seasons, nurturing an astonishing biologically diverse collection of aquatic plants and helping to support a dense array of animal species. The name “Pantanal” comes from the Portuguese word pântano, meaning wetland, bog, swamp, quagmire or marsh. By comparison, the Brazilian highlands are locally referred to as the planalto, plateau or, literally, high plain.