|Araguaian River Dolphin|
|Common Name||Araguaian Boto|
|Range||Araguaia–Tocantins basin of Brazil.|
The Araguaian river dolphin, or Araguaian boto, (Inia araguaiaensis), is a new species of river dolphin population whose identification as a species distinct from the Amazon river dolphin was announced in 2014. It is native to the Araguaia–Tocantins basin of Brazil.
The recognition of the Araguaian river dolphin as a separate species was announced on January 22, 2014. It was distinguished from other members of Inia on the basis of nuclear Microsatellite and mitochondrial DNA data as well as differences in skull morphology (it generally has a wider skull). It also differs from the Amazon and Bolivian river dolphins in the number of teeth per hemimandible (24–28 versus 25–29 and 31–35, respectively). It is the first new river dolphin species to be described since 1918.
Members of the genus are gray to pink in color and have a body length range from 1.53 to 2.6 m (5.0 to 8.5 ft). They have a dorsal ridge rather than a fin. Their neck vertebrae are unfused, allowing them to turn their heads sharply. Like other river dolphins, the Araguaian river dolphin has a prominent forehead and a much longer snout than those of most marine dolphins, as well as smaller eyes than marine dolphins. Because their aquatic environment is often turbid, their vision is not as well developed. River dolphins tend to be less active than marine dolphins. They feed mainly on fish, aided by echolocation.