Differs from other species of the subfamily Trichomycterinae by the extreme elongation of the opercle and narrow odontode-bearing distal plate. Further differs by having elongated and curved coronoid process of the lower jaw. The lack of pelvic fin and girdle further differs this species from all other Trichomycterinae except Eremophilus mutisii, E. candidus and Trichomycterus catamarcensis, species that are readily distinguished from Silvinichthys bortayro by their coloration pattern. The pale integumentary pigmentation and reduction of the eyes are troglomorphic characters that are paralleled only in cave-dwelling species Trichomycterus itacarambiensis and T. chaberti among presently known trichomycterines. Can be easily distinguished from those two species by its proportionally much shorter body and fewer pectoral-fin rays (6 vs 7 and 10, respectively). Further differs except Silvinichthys mendozensis by the absece of a latero-sensory canal branch in the frontal and sphenotic; and also differs from S. mendozensis in having 6 versus 7 or 8 pectoral-fin rays and the absence versus presence of the pelvic fin and girdle (Ref. 55738).