This species belongs to the Farlowella acus species group by the presence of long breeding odontodes on the snout in mature males, four rows of lateral body plates from the anteriormost portion of body to posterior margin of dorsal- and anal-fin base, and two complete rows of ventral plates and no single plate between pelvic-fin insertions. Diagnosed from other members of the F. acus species group by having the median anterior lateral row of plates diamond-shaped (vs. hexagonal in shape in F. acus, F. colombiensis, F. martini, F. venezuelensis and F. vittata). Further differs from F. martini by having dark interradial membranes on the caudal fin (vs. interradial membranes clear in F. martini). Distinguished from members of the Farlowella curtirostra species group by having restricted odontodes on sides of the snout but not extending onto the cheek region (vs. hypertrophied odontodes in breeding males extensive on sides of the snout and cheek); from members of the F. amazona species group by having notably concave lateral margins of the snout (vs. lateral margins of the snout straight to nearly straight) and eyes not elevated on the head (vs. eyes elevated on the head); from species of the Farlowella nattereri species group as well as from Farlowella gracilis by having four rows of lateral plates (vs. five rows in F. gracilis and F. nattereri species group); and from species of the F. knerii and F. mariaelenae species groups by having two abdominal plate rows (vs. three abdominal rows in the F. knerii and F. mariaelenae species groups) (Ref. 94974).