This species is distinguished from all its congeners, except H. affinis, H. punctatus, H. ancistroides, H. commersoni, by the following characters: teeth bifid (vs. spoon-shaped); dark spots on light background (vs. light spots on a dark background or not spotted); with 4 rough lateral ridges on flanks (vs. no strong ridges on flanks); lateral series plates 26-29 (vs. < 28 in several species, 31-32 in H. laplatae); differs from H. laplatae with 1-2 plates bordering posterior margin of supraoccipital bone (vs. 3-4); differs from H. affinis, H. punctatus, H. ancistroides by its inter-dorsal distance 14.7-20.4% in SL (vs. 18.9-21.0%) and with head depth 48.8-76.4% in HL (vs. 48.2-49.9%); differs from H. commersoni by having large lateral ridges with odontodes posteriorly inclined (vs. fine and with odontodes in all directions), strong lateral ridges in caudal peduncle (vs. weak), mid lateral ridge from 2nd or 3rd plate (vs. from first plate), adults (> 12 cm SL) with a very weak ridge on temporal plate (vs. strong ridge) (Ref. 121236).