Considered a synonym of Gambusia affinis (Baird & Girard, 1853)
- Baird, Spencer F. & C.F. Girard. 1853. "Descriptions of new species of fishes collected by Mr. John H. Clark, on the U. S. and Mexican Boundary Survey, under Lt. Col. Jas. D. Graham". Proceedings of the Academy of Natural Sciences of Philadelphia. 6:387-390 (ffm04562)
Original description as Gambusia myersi:
- Ahl, Ernst. 1923. "Gambusia modesta sp. n". Blätter für Aquarien- und Terrarien-Kunde. Stuttgart. 34:220-221 (ffm04572)