Xingu River ray mostly brownish-dusky (large white center to underparts of "P. henlei"). Compared to "P. albimaculata", "P. leopoldi" has fewer and larger yellowish-white spots above. Xingu River ray The Xingu River ray, white-blotched river stingray, or polka-dot stingray ("Potamotrygon leopoldi") is a species of freshwater fish in the family Potamotrygonidae. It is endemic to the Xingu River basin in Brazil and prefers rocky bottoms. It is sometimes kept in aquaria. "P. leopoldi" reaches up to in disc width, in total length and in weight. Females grow larger than males. It is closely related to the similar "P. henlei" from the Tocantins River
American River American River The American River (Río de los Americanos during the period before 1847 ruled by Mexico) is a 120-mile-long river in California that runs from the Sierra Nevada mountain range to its confluence with the Sacramento River in the Sacramento Valley. Via the Sacramento River, it is part of the San Francisco Bay watershed. This river is fed by the melting snowpack of the Sierra Nevada and its many headwaters and tributaries, including the North Fork American River, the Middle Fork American River, and the South Fork American River. The American river is known for the discovery of gold