In 2011, researchers discovered two new species of freshwater stingrays in the Amazon River.
The Heliotrygon (rosai and gomesi), commonly referred to as the Pancake stingrays, is the first new genus of stingrays from the Amazon described since 1987.
Waters in Lake Superior used to be the cleanest among all Great Lakes.
Today, the waters of Lake Huron and Lake Michigan are filtered because of the invasive quagga mussels that live there. Thus, both lakes surpass Lake Superior in clarity.
In 1951, American John Goddard and two French explorers were the first to swim the entire river successfully.
The 9-month expedition began at the source of the Nile in Burundi. Explorers covered about 6 800 km (4 225 mi) before reaching the mouth at the Mediterranean Sea.
