This species is distinguished from other species in the Rivulus santensis group in having scales in longitudinal series 30-31 (vs. 32-36); caudal fin light yellow, with a dark gray broad margin along the whole fin (except R. nudiventris, vs. absent in R. depressus, R. lazzarotoi, R. simplicis; margin restricted to dorsal and ventral margins of the caudal fin in R. janeiroensis, R, santensis, and R. haraldsiolii; and black margin, middle with bright green and dark reddish brown to black longitudinal lines in R. luelingi); dorsal part of caudal fin base in females with a small, horizontally elongated black spot (vs. rounded or triangular). This species differs from R. nudiventris by having a pelvic fin (vs. none), lesser caudal-fin rays 25-29 (vs. 30-31) and anal-fin rays 12-13 (vs. 14) (Ref. 78703).