A new species of Jupiaba Zanata is described from tributaries of the rio Aripuanã, rio Madeira basin, Amazonas and Mato Grosso States, Brazil. The new species can be diagnosed from its congeners (except J. abramoides, J. anteroides, and J. poranga) by having two vertically-elongated humeral blotches, the anterior usually with a darker median portion forming an horizontally-elongated trace pointed anteriorly, and a well defined dark longitudinal line extending from the second humeral blotch to the caudal peduncle. The new species differs from J. abramoides, J. anteroides, and J. poranga by having an elongated blotch over caudal peduncle that extends to the distal tip of the caudal-fin median rays. Also, it can be distinguished from most congeners by the combination of relatively high number of lateral line scales, predorsal median line without a series of scales, dentary teeth decreasing abruptly in size towards posterior portion, and presence of a larger central teeth cusp.
Taxonomy; Small characid; Neotropical fish; South America
