The banded killifish has a narrow, elongate bluish-gray or olive-colored body with a darker dorsal surface and white or yellowish underparts extending to the anal fin. Spawning males develop yellow pectoral and pelvic fins, a bright blue patch on the anal fin, and brilliant blue iridescence on the lower portion of the body including the area around the anal fin. There are 12–20 vertical bands along the sides. In females the bands usually appear as thin and distinct black bands that often do not span the full width of the body. In males, the bands are silvery in color, are less distinct, and are closer together. The number of bands are useful in sexing an individual; male banded killifish have a greater (approximately >9) number of bands anterior to the dorsal fin. Fins rounded, base of first dorsal ray slightly ahead of or directly over first anal ray. Snout is blunt, with small superior mouth and projecting lower jaw. Lateral line is missing; 39–43 scales in the lateral series. 10–13 dorsal fin rays, 9–11 anal fin rays, 6 pelvic fin rays. Max length TL, average length TL.