Boto

Boto is a Portuguese name given to several types of dolphins and river dolphins native to the Amazon and the Orinoco River tributaries. A few botos exist exclusively in fresh water, and these are often considered primitive dolphins.
Classification.
The botos are a paraphyletic group, defined largely by their evolutionary convergences.
The genus "Sotalia" is divided into two species. The costero ("S. guianensis") is distributed in the Atlantic, from Florianópolis in Santa Catarina, Brazil, and northwards. The tucuxi ("S. fluviatilis") lives in the rivers of the Amazon.
Burmeister's porpoise is marine and lives from Santa Catarina to the south.
The Amazon river dolphin ("Inia geoffrensis") thrives in fresh water, is endemic to the Amazon basin, and is placed in the Endangered category of the IUCN.
The Araguaian river dolphin ("I. araguaiaensis") is a newly identified species native to the Araguaia-Tocantins basin of Brazil.
The La Plata dolphin ("Pontoporia blainvillei"), another vulnerable Brazilian denizen, is a marine river dolphin that ranges from Espírito Santo, Brazil, to the south.
Folklore.
The 'boto' of the Amazon River regions of northern Brazil, are described according to local lore as taking the form of a human or merman, also known as "encantado" ("enchanted one" in Portuguese) and with the habit of seducing human women and impregnating them.