Distinguished from all other species of Knodus by the presence of thickened skin forming folds covering the basal portion of the six anteriormost branched anal-fin rays and its interradial membrane. Differs also uniquely among its congeners by having the six anteriormost branched rays associated with more developed skin considerably thicker than that on the remaining anal-fin rays. Can be differentiated also from all congeners, except Knodus meridae, by the low number of branched anal-fin rays (14-16 vs. more than 17), by the presence of relatively compressed teeth (vs. teeth bulky in remaining Knodus and Bryconamericus species, with the exception of Bryconamericus deuteronoides), and the presence of a broad, silvery-gray midlateral stripe (midlateral stripe in remaining Knodus and Bryconamericus species relatively narrow) (Ref. 75965).

Description: Dorsal fin ii,8; Anal fin vii, 14, 15 or 16; Pectoral fin i+10 or 11; Pelvic fin i6i (Ref. 75965).