Can be diagnosed from Hemiodus quadrimaculatus group and from H. ternetz i, H. thayeria and H. tocantinenss by the presence of a midlateral round spot and absence of uninterrupted longitudinal dark stripe from the opercular margin to the base of the caudal fin. Differs from the species of the Hemiodus quadrimaculatus group by having the following characters: 43-46 perforated scales in the lateral line; eight or nine longitudinal series of scales above the lateral line; five longitudinal series of scales below the lateral line; 10-12 teeth on the upper jaw. Distinguished from other species of Hemiodus , except those mentioned above, by the form of the distal border of the multicuspid teeth (vertically elongate, forming an arrowhead v. teeth with border straight or convex). Differs from all congeners, except Hemiodus atranalis , by having the first branched dorsal-fin ray elongated in the largest specimens (v. lacking such elongation) (Ref. 93237).