Distinguished from Silvinichthys bortayro by the following characters: triangular shape of the head from a dorsal view (vs. more rectangular); 8-11 (vs. 2-4) opercular odontodes and 21-28 (vs. 9-12) interopercle odontodes apparent in cleared and stained specimens; 11-13 dorsal-fin rays (vs. 9); caudal-peduncle depth 8.8-10.9% SL (vs. 8.0-8.3% SL); snout length 43.3-61.9% HL (vs. 38.2-40.5% HL); head with broadly separated, dark, marmorated bands of pigmentation and body with a more concentrated, but still diffuse, patch of darker pigmentation overlying the dorsal surface of the cranium and the dorsal portions of the pectoral girdle (vs. lacks the dark marmorated pigmentation in larger individuals); absence of dark midlateral stripe on the caudal peduncle at all sizes (vs. presence of a dark midlateral stripe in mid-sized specimens). Differs from S. gualcamayo by the caudal peduncle length 19.3-21.5 % SL (vs. 22.0-23.9% ) and the insertion point of the first proximal dorsal-fin pterygiophore is posterior to the neural spine of vertebra 21 (vs. 22); from S. leoncitensis by having 37-39 vertebrae (vs. 40), 16-18 ribs on each side (vs. 20); 6-7 pectoral-fin rays (vs. 8), body depth 12.6-16.5 % SL (vs. 8.4-12.2% SL), caudal-peduncle depth 8.8-10.9% SL (vs. 6.6-8.6% SL), and the insertion point of the first proximal dorsal-fin pterygiophore posterior to the neural spine of vertebra 21 (vs. 23); and from S. mendozensis by the absence of pelvic fin and pelvic-fin girdle (vs. presence) and 21-28 (vs. 30-42) interopercle odontodes apparent in cleared and stained specimens (Ref. 95056).

Description: Dorsal fin with 3-5 unbranched rays and 7-8 branched rays; anal fin with 2-4 unbranched rays and 6 or 7 branched rays (Ref. 95056).