Original description as Gambusia eurystoma:
- Miller, Robert Rush. 1975. "Five new species of Mexican poeciliid fishes of the genera Poecilia, Gambusia, and Poeciliopsis". Occasional Papers of the Museum of Zoology, University of Michigan. (n. 674), pp. 1-44 (ffm04575)
Conservation: Gambusia eurystoma is evaluated by the international union for the conservation of nature in the iucn red list of threatened species as (CR) critically endangered (2018).