Probolodus sazimai is distinguished from its two congeners, P. heterostomus, P. oyakawai, by the following characters: six transverse series of scales from insertion of pelvic fin to lateral line (vs. seven/eight); 12 scales along middorsal line between posterior termination of base of dorsal fin and adipose fin (vs. 14-17 and 13-16, respectively); two pairs of uroneurals (vs. absent or just one pair); anterior margin of the hypurals 2 and 3 in contact, not fused (vs. hypurals 2 and 3 distinctly separate); end piece or stay of the dorsal fin leaning against or fused in the last pterygiophore (vs. somewhat removed of the last pterygiophore); fourth basibranchial completely cartilaginous (vs. ossified); dorsal margin of the opercle more elevated than the hyomandibular (vs. opercle and hyomandibular practically aligned); anteromedially projection of the mesethmoid wide, separating completely the premaxillary (vs. short projection, not separating completely the premaxillary). It can be further differentiated from P. heterostomus by having 36-43 perforated scales on the lateral line (vs. 45-56 perforated scales) (Ref. 96884) (Ref. 96884).

Description: Dorsal-fin rays ii,9; anal-fin rays iv or v, 22-27; pectoral-fin rays i,10,I; i,11; i,11,i or i,12; pelvic-fin rays i,6 or i,6,i, or i,7 (Ref. 96884).