Callichthys serralabium is a tropical freshwater fish belonging to the Callichthyinae sub-family of the family Callichthyidae.

It also has 8–9 branched rays in the pectoral fin (instead of 6–7) and an irregular color pattern of dark, diffuse blotches on flanks of adults.

The body profile between snout and dorsal-fin origin straight to slightly convex.

The pectoral fin spine has stronger odontodes anteriorly and small retrorse hooks posteriorly.

The pectoral spine of fully developed nuptial males is elongated and thick.