Brazilian ichthyologist Mauro Luís Triques described E. vicentespelaea in a 1996 volume of the scientific journal Revue Française de Aquariologie, from two specimens caught in 1978.

[3][4] Eigenmannia vicentespelaea has an elongated, laterally compressed body with curved dorsal and ventral profiles, tapering to a filament without a caudal fin.

The posterior pair of nares are positioned close to the eyes, which are reduced in size or, in a minority of individuals, externally absent.

As far as known, all South American knifefishes are capable of generating an electric field for electrolocation; this adaptation for activity in low light conditions would have been conducive to them colonizing completely dark cave environments.

The relatively larger size attained by E. vicentespelaea compared to its sister species may indicate a release from predation or competition once it became cave-dwelling.