Northern platyfish

The northern platyfish (Xiphophorus gordoni) is a species of fish in the Poeciliidae family. It is endemic to Mexico. It was named in honor of Myron Gordon by Robert Rush Miller and W. L. Minckley who discovered it with Carl Hubbs on a 1961 expedition.

Its natural habitat is a hot spring heated by volcanic activity, in Santa Tecla, Mexico. The water is "shallow, sulphur smelling", and vegetation choked. "Water temperatures in its biotope range from the mid 80s to the high 90s", making it difficult for all but the most dedicated aquarists to keep it in captivity. Due to canal construction at the spring, it is not known if a viable wild population survives, or if the fish has used the canals to extend its range.