A new species of Scoloplax is described from small tributaries of rio Aripuanã, rio Madeira drainage, Amazonas State, Brazil. The new species can be distinguished from its congeners by several morphological features, such as ventral midline plates with two longitudinal parallel rows of odontodes not covered by skin, pectoral and pelvic fins with all rays simple, unbranched, and mesethmoid with a thickened triangular anterior process. Implications of new records of S. dolicholophia from rio Japurá and other comparative features within the genus are discussed.
Taxonomy; Neotropical; Systematics; Siluriformes
