Xingu River ray 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 basin and "P. albimaculata" from the Tapajós River basin. Compared to "P. henlei", "P. leopoldi" is deeper black above and its underparts are
South Fork American River Creek, and Silver Fork American River. Most of the watershed consists of high, forested mountains and steep-sided valleys that receive up to of annual precipitation, except for the westernmost section which consists of drier foothill country. The river also contributes about a third of the total outflow of the American River system. According to a U.S. Geological Survey stream gage at Lotus, about above Folsom Lake, the average discharge was from 1951 to 1995. The highest recorded flow was on January 1, 1997 (see ), and the lowest monthly mean was in July 1977. Rafting and Kayaking The South Fork