This species is distinguished from S. mendozensis by the absence of pelvic girdle and fin (vs. present), the number of interopercle odontodes 14-18 (vs. 30-42), the marmorated pigmentation on the body and head (vs. uniformly brown); differs from S. bortayro by the number of branched pectoral–fin rays 7 (vs. 5), the number of total dorsal-fin rays 11 (vs. 9), the anal base fin 10.2-11.7% SL (vs. 8.8-10.2), the supraorbital tendon bone wide (vs. slender), the dark marmorated pigmentation on the body and head (vs. no dark pigmentation in larger individuals), the nasal barbel length 27.3-39.0% SL (vs. 47.1-74.4), the maxillary barbel length 39.5-61.7% SL (vs. 60.5-105.9), the submaxillary barbel length 24.7-41.9% SL (vs. 41.2-57.1), the snout length 40.6-44.4% HL (vs. 35.8-40.5), the number of opercular odontodes 6-8 (vs. 2-4), the number of interopercle

odontodes 14-18 (vs. 9-12); differs from S. huachi by the body depth 10.1-12.6% SL (vs. 12.6-16.5), the supraorbital tendon bone wide (vs. slender), the number of interopercle odontodes 14-18 (vs. 21-28), the number of branchiostegal rays 6 (vs. 7-8), the number of dorsal procurrent caudal-fin rays 14 (vs. 11), the number of ventral procurrent caudal-fin rays 15 (vs. 10); differs from S. gualcamayo by the caudal peduncle length 19.3-21.5% SL (vs. 21.1-23.6), the head depth 9.9-12.2% SL (vs. 9.1-9.8), the interorbital wide 28.3-36.1% HL (vs. 26.1-27.8), the number of branchiostegal rays 6 (vs. 7), the number of dorsal procurrent caudal-fin rays 14 (vs. 11), the number of ventral procurrent caudal-fin rays 15 (vs. 9), the number of total vertebrae 39 (vs. 38); differs from S. leoncitensis by the total number of dorsal-fin rays 11 (vs. 13), the number of dorsal pterygiophore 7 (vs. 8), the number of ribs 16 (vs. 20), the number of total vertebrae 39 (vs. 40), and the number of interopercle odontodes 14-18 (vs. 18-28) (Ref. 122377).