The book Peixes do Rio Negro [Fish of the River Rio Negro], organized by Mônica de Toledo-Piza Ragazzo, from the Biosciences Institute of the University of São Paulo (USP), and recently published by ...

Scientists discovered new fish species. These include a blob-headed catfish, a tiny pipehorse, and three pacu species.

Wild oscars are the default type of oscar fish. The original species of Astronotus ocellatus is native to the Amazon River basin, the Paraguay River, the Rio Negro and the Parana River.