Distinguished from all other species of Pseudanos by having the following characters: three branchiostegal rays (vs. four in P. gracilis and most specimens of P. winterbottomi); dark transversal bars on dorsum absent (vs. present in P. trimaculatus); dark spots present on the center of each body scale, forming conspicuous, straight dark lines (vs. dark spots absent in P. gracilis; and in some specimens of P. trimaculatus), four midlateral dark blotches on body (vs. usually two, sometimes three or four in P. trimaculatus, or body lacking midlateral blotches and presenting instead a broad midlateral stripe in P. winterbottomi); angle of the dorsal and ventralmost radii of body scales between 40° and 90° (vs. angle between 110° and 180° in P. gracilis and P. trimaculatus); and cranial fontanel opened along its entire length (vs. cranial fontanel partially closed in P. trimaculatus) (Ref. 91907).