This species is similar to Nematolebias papilliferus and distinguished from N. whitei by having long narrow golden lines on the distal portion of the dorsal fin in males (vs. dots). It differs from N. papilliferus by its distinct row of small iridescent spots on the distal margin of the caudal fin in males (vs. row absent); and from both N. papilliferus and N. whitei by its pelvic-fin bases medially separated by a small interspace (vs. in contact) (Ref. 95536).

Description: dorsal-fin rays 16-18 in males, 13-15 in females; anal-fin rays 23-24 in males, 20-22 in females; pectoral-fin rays 14-15 in males; 13-14 in females; pelvic-fin rays 6 in both sexes; caudal fin rounded; longitudinal series of scales 29-31; and transverse series of scales 7-8 (Ref. 95536).