Potamotrygon albimaculata is a member of the black stingray species group and is distinguished by having blackish brown dorsal disc color with numerous and generally evenly-spaced small whitish spots and faint ocelli, multiple rows of thorns broadly spread on dorsal and lateral tail, pelvic fins with broadly rounded apices, and two angular cartilages with the posterior far more slender but about as wide as the anterior angular (Ref. 115937).