Diagnosed from all congeners except Rineloricaria maquinensis by its unique pattern of abdominal plates: abdomen almost completely naked, except for a single preanal complex of plates, connected to the lateral abdominal plates by one or two small squarish platelets at the base of pelvic-fin spine (vs. squarish platelets absent in specimens with naked or almost naked abdomens). Can be differentiated from Rineloricaria maquinensis by the following body proportions: longer predorsal length (31.2-35.0 vs. 28.2-31.5% SL), shorter postanal length (52.3-56.4 vs. 55.5-62.5% SL), longer abdominal length (15.2-17.8 vs. 13.6-15.5% SL), wider cleithral width (16.8-19.6 vs. 13.7-16.5% SL), and a deeper head (43.2-64.8 vs. 37.4-43.9% HL). Differs further Rineloricaria aequalicuspis by its asymmetrical tooth cusps (vs. almost symmetrical cusps) (Ref. 75788).