Boto is aPortuguese name given to several types ofdolphins andriver dolphins native to theAmazon and theOrinoco River tributaries. A few botos exist exclusively infresh water, and these are often considered primitive dolphins.
The botos are aparaphyletic group, defined largely by theirevolutionary convergences.
The genusSotalia is divided into twospecies. Thecostero (S. guianensis) is distributed in the Atlantic, fromFlorianópolis inSanta Catarina, Brazil, and northwards. Thetucuxi (S. fluviatilis) lives in therivers of the Amazon.
Burmeister's porpoise is marine and lives from Santa Catarina to the south.
TheAmazon river dolphin (Inia geoffrensis) thrives in fresh water, is endemic to theAmazon basin, and is placed in theEndangered category of the IUCN.[1]
TheAraguaian river dolphin (I. araguaiaensis) is a newly identified species native to theAraguaia-Tocantins basin ofBrazil.[2]
TheLa Plata dolphin (Pontoporia blainvillei), another vulnerable Brazilian denizen, is amarine river dolphin that ranges fromEspírito Santo, Brazil, to the south.[3]
The "boto" of the Amazon River regions of northernBrazil are described according to local lore as taking the form of a human ormerman, also known asboto-cor-de-rosa ("pink boto" inPortuguese) and with the habit of seducing human women and impregnating them.[4]