The Amistad gambusia (''Gambusia amistadensis'') is an extinct species of small fish known only from a single locality, the large vegetated Goodenough Spring in

Val Verde County Val Verde County is a County (United States), county located on the southern Edwards Plateau in the U.S. state of Texas. The 2020 population is 47,586. Its county seat is Del Rio, Texas, Del Rio. In 1936, Val Verde County received Recorded Te ...

, Texas. It apparently was driven to extinction in the wild when its habitat was submerged to a depth of about 70 feet by the construction of the

Amistad Reservoir Amistad Reservoir ( es, Presa Amistad) is a reservoir on the Rio Grande at its confluence with the Devils River northwest of Del Rio, Texas. The lake is bounded by Val Verde County on the United States side of the international border and by th ...

in 1968. The two captive populations, at the

University of Texas System The University of Texas System (UT System) is an American government entity of the state of Texas that includes 13 higher educational institutions throughout the state including eight universities and five independent health institutions. The UT& ...

and the Dexter National Fish Hatchery in New Mexico, later failed through

hybridization Hybridization (or hybridisation) may refer to: *Hybridization (biology), the process of combining different varieties of organisms to create a hybrid *Orbital hybridization, in chemistry, the mixing of atomic orbitals into new hybrid orbitals *Nu ...

with the related

mosquitofish The western Mosquitofish (''Gambusia affinis'') is a North American freshwater fish, also known commonly, if ambiguously, as simply Mosquitofish or by its generic name, ''Gambusia'', or by the common name gambezi. Its sister species, the easte ...

and predation. The species has been classified as

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

by the United States Fish and Wildlife Service since 1987, and by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

since 2013.

References

Further reading