What is "yanamayu"

Yanamayu ( Quechua yana black, mayu river, "black river", hispanicized spelling Yanamayo) is a river in the Ancash Region in Peru. It flows along the border between the provinces Carlos Fermín Fitzcarrald and Mariscal Luzuriaga until emptying into Marañón River as a left tributary. The confluence is on the border of the districts Eleazar Guzman Barron, San Nicolás and Canchabamba.