Astroblepus ortegai can be diagnosed from all congeners by its adipose fin which is a membrane without spine and by having the following characters: maxillary wattle doesn't reach beyond the oral disk; first pectoral radius is shorter than head longitude and has 9 soft branching radii, 6 of them associated to the third radial; first radius of pelvic fin doesn't go beyond the anus; pre-maxillary with two internal rows of bicuspid teeth, the outermost row has 13 tricuspid teeth; first simple radii of caudal fin without extension; 24 free vertebrae, and fifth cerato-branchial bone having 17 teeth in the anterior region (Ref. 93748).