Zoogoneticus tequila
Its current distribution is restricted to a single spring pool in Teuchitlán, only 4 metres (13 ft) in diameter, where a population consisting of less than 50 adult fish found in the early 2000s.
[6] Before the discovery of the pool population in 2000/2001, Z. 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.
[6][7] The small pool where the endemic population of Z. tequila currently inhabits is made of mostly mud and silt, along with rocks, sand, and minimal vegetation.
[7] [10] With such a small population of minimal juveniles and a few adults, Z. tequila was particularly threatened by inbreeding and poor genetic variation, ultimately facing the threat of extinction before any reintroduction efforts were made.
[4] Additionally, introduced species that drive competition up to a nearly impossible level for this fish is another factor attributed to the initial population decline.
[14] Much of the wild diet and eating patterns of Z. tequila are inferred from congeners such as Z. quitzeoensis, which consists of amphipods, insects, ostracods, and detritus.
[18] There are also many introduced species in the area that likely prey on or outcompeted Z. tequila such as Xiphophorus maculatus, Tilapia aurea, Lepomis macrochirus, Cyprinus carpio, X. helleri and Poecilia reticulata.
This project came from the collaboration of zoologists from Chester Zoo and European institutions, ultimately creating a lab with Mexican scientists to bring this species to recovery.
[23] Freshwater fish particularly face a large threat of extinction due to the proportionally higher rate of endemic species in these regions.
However, the research that has been done to understand the cause of the Z. tequila going extinct in the wild largely attributes anthropogenic pollution as well as the introduction of invasive species to be the largest reasons.
[8] Having an environment in which the minimal, endemic population can grow past a point where inbreeding poses a significant threat is a main driver in recent efforts.
