Trichomycterus santanderensis can be distinguished from other species of the genus by the following combination of characters: variable reduction in eyes from visible to imperceptible

due to covering by a thick integument; relatively high head (62.5% of HL); enlarged mouth width (49% of HL); extended maxillary, nasal and rictal barbels (113.6%, 106.7% and 75% of HL, respectively); first pectoral ray extending as long filament, about 95% of pectoral-fin length; depth of the caudal peduncle 17.5% SL; caudal fin truncate with a slightly convex edge, upper portion of fin longer than lower portion; color varied from homogeneous light-red pigmentation of adults to pale rose with small grayish round spots on dorsum of young individuals (Ref. 58751).