This is distinguished from other species of Spectracanthicus by its color pattern consisting of large, white spots (vs. small yellowish dots in S. murinus, S. punctatissimus, and S. tocantinensis , and dark gray lacking dots in S. immaculatus). It also differs from congeners, except S. murinus, by having larger orbital diameter up to 29.2% of HL (vs. up to 25.7% in S. punctatissimus, 20.3% in S. tocantinensis, 16.2% in S. immaculatus). It can be further separated from S. murinus by having rounded dorsal view of the snout, bar-shaped, eversible opercle with conspicuous odontodes, and four unbranched anal-fin rays (vs. snout slightly pointed; opercle triangle-shaped, not eversible, lacking conspicuous odontodes; three anal-fin unbranched rays); from S. tocantinensis by having 19-43 dentary teeth (vs. 8-16) and by the infraorbital 4 forming just a small area of orbit (vs. forming posterior edge of orbit almost totally) (Ref. 95496).

Description: Dorsal-fin rays i,7; anal-fin rays i,4; pectoral-fin rays i,6; pelvic-fin rays i,5; dorsal-fin spinelet V-shaped with locking mechanism; dorsal-fin base very long, its length equivalent to 12 dorsal plates, reaching pre-adipose plate and connected to adipose fin by thick membrane.(Ref. 95496).