The Amistad gambusia (''Gambusia amistadensis'') is an extinct species of small

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

known only from a single locality, the large vegetated Goodenough Spring in Val Verde County,

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

. 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 with the related mosquitofish and predation. The species has been classified as extinct by the

United States Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with othe ...

since 1987, and by the IUCN since 2013.

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Further reading