News Plus慢速英语:巴西科学家亚马逊阿拉瓜亚河域发现河豚新物种

You're listening to NEWS Plus Special English. I'm Mark Griffiths in Beijing.
Now from the United States to Brazil. Scientists have made the first discovery in 100 years of a new river dolphin species in the waters of the Araguaia River in Brazil's vast Amazon rainforest.
The discovery of the species was officially announced one week ago in a study posted online by the Plos One scientific journal in Brazil.
The study's lead author, biologist Tomas Hrbek, of the Federal University of Amazonas in the city of Manaus, says the new species is the third ever found in the Amazon region.

Hrbek says it was an unexpected discovery that shows just how incipient our knowledge is of the region's biodiversity.
He says river dolphins are among the rarest and most endangered of all vertebrates, so discovering a new species is something that is very rare and exciting.
The scientist says people always saw them in the river but no one ever took a close up look at them.
Scientists concluded the large dolphin was a new species by analyzing and comparing DNA samples of several types of dolphins from the Amazon and the river basins.
The Araguaia dolphin is very similar to its Amazon River cousin although somewhat smaller and with fewer teeth.
There are about 1,000 dolphins of this species living in the 2,600-kilometer long Araguaia River.