Original description as Xenotoca lyonsi:
- Domínguez Domínguez, Omar & D.M Bernal-Zuñiga, K.R. Pyler. 2016. "Two new species of the genus Xenotoca Hubbs and Turner, 1939 (Teleostei, Goodeidae) from central-western Mexico". Zootaxa. 4189(1):81-98. DOI: 10.11646/zootaxa.4189.1.3 (ffm00865) (abstract)
Conservation: Xenotoca lyonsi is evaluated by the international union for the conservation of nature in the iucn red list of threatened species as (CR) critically endangered (2018). Xenotoca lyonsi is known only from a few sites along its original distributional range, and is reported to have been extirpated from approximately 60% of the historical localities where it has been reported. All the areas where the species originally occurred are highly impacted by human activities, being totally modified for agricultural purposes, with sugar cane plantations demanding high water resources and discharging polluted water from the production process. Also, untreated urban waste into the river is a substantial ecological problem in the area. In several recent surveys for the species, it was never located downstream of the village waste water discharges and, when found, it was always upstream of the discharge sites. Also, the species is not abundant in the few localities from where it is currently known to exist (Domínguez Domínguez et al., 2016:93, Lyons et al., 2019:145, Köck, 2019).