It is the first time an extinct species of fish has been successfully reintroduced in Mexico

Tequila fish, which disappeared from the wild in 2003 due to pollution and the introduction of invasive species, has been successfully reintroduced in a river in Jalisco, Mexico, and is once again thriving in its natural habitat.

Zoogoneticus tequila, Tequila splitfin, or simply Tequila fish, is a species of goodeid fish (family Goodeidae) from Mexico. The specific epithet, tequila, derives from the Tequila Volcano, which looms near the type locality.

Zoogoneticus tequila is endemic to the Ameca River basin in west-central Mexico. Its current distribution is restricted to a single spring pool in Teuchitlán, only 4 meters ( in diameter, where a population consisting of less than 50 adult fish lives.[ Even in this habitat, it is outnumbered by introduced guppies by a factor of six Before the discovery of the pool population in 2000/2001, Zoogoneticus tequila was generally thought to inhabit rivers; however, no fish could be found in the original habitat and the species was considered extinct in the wild

The tequila splitfin is a freshwater species belonging to the Goodeid family of fish (named after American ichthyologist George Brown Goode) and is native to the Teuchitlán River in the state of Jalisco in southwest Mexico.