 This species was described by Spencer Fullerton Baird as "Hydrargyra luciae" in 1855 with the type locality given as Robinson's Landing, Peck's Beach, opposite Beesley's Point, Cape May County.Baird gave it the specific name "luciae" in honor of his daughter, Lucy Hunter Baird (1848-1913).The spotfin killifish is the smallest member of its genus, rarely exceeding 50 mm total length or 40 mm standard length.