This species is distinguished from its congeners by the following characters: absence of an adipose fin or azygous plates at the typical adipose-fin location (vs. reduced adipose fin or azygous plates in N. botucatu, N. paranensis nd a fully-developed adipose fin in all other species); differs from N. botucatu, N. paranensis by having a dark caudal fin with a unique v-shaped hyaline vertical area (vs. dark caudal fin with several irregular hyaline vertical bands) and having lower lip reaching or almost reaching branquial apertures transversal line (vs. far from reaching branquial apertures transversal line) (Ref. 119403).