Symphurus multimaculatus is distinguished from all congeners by the combination of: 1–2–2–

2–2 ID pattern, 14 caudal-fin rays, 9 abdominal vertebrae, 50–51 total vertebrae, 5 hypurals, 92–94 dorsal-fin rays, 79–82 anal-fin rays, 102–108 longitudinal scales, 45–48 scales in a transverse row, a small eye (9.1–10.1% HL), deep body (28.6–35.1% SL), and blind-side pigmentation featuring conspicuous, irregular, blackish-brown speckles especially conspicuous overlying pterygiophore regions of the dorsal and anal fins (Ref. 82202).