an Entity references as follows:
The Chiapas swordtail or upland swordtail (Xiphophorus alvarezi) is a species of livebearing freshwater fish of family Poeciliidae, and genus Xiphophorus. It is, therefore, in the same genus as the common platy and the swordtail. The Chiapas swordtail was discovered and first described by in 1960, along with four other species of Xiphophorus.