''Cyprinodon longidorsalis'', the cachorrito de charco palmal or La Palma pupfish, is a species of

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 li ...

in the family Cyprinodontidae. It was

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the Ojo de Agua la Presa in southwestern

Nuevo Leon Nuevo is the Spanish word for "new". It may refer to: * Nuevo, California, a town in the state of California * Nuevo (band), featuring singer and musician Peter Godwin * Nuevo (Bayamón), a settlement in Puerto Rico * "Nuevo", Spanish-language vers ...

state in

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

, but became

extinct in the wild A species that is extinct in the wild (EW) is one that has been categorized by the International Union for Conservation of Nature as known only by living members kept in captivity or as a naturalized population outside its historic range due ...

in 1994 due to habitat loss (now survives only in captivity). The same freshwater spring system was the home of three other pupfish: '' Cyprinodon ceciliae'' (extinct), '' Cyprinodon inmemoriam'' (extinct) and '' Cyprinodon veronicae'' (extinct in the wild, survives in captivity). Although these were from the same spring system, each was restricted to its own individual spring pool. The Charco La Palma pool and its spring had a combined area of about and was no more than at the deepest point, making the range of the La Palma pupfish perhaps the smallest known for any vertebrate species. This tiny spring pond also was the home of a now-extinct,

undescribed species In taxonomy, an undescribed taxon is a taxon (for example, a species) that has been discovered, but not yet formally described and named. The various Nomenclature Codes specify the requirements for a new taxon to be validly described and named. U ...

of ''

Cambarellus ''Cambarellus'' is a genus of small freshwater crayfish in the family Cambaridae. The 19 species are found in Mexico (subgenus ''Cambarellus'') and the Gulf States of the United States (subgenus ''Pandicambarus''). Among the Mexican species, ' ...

'' crayfish. The La Palma pupfish is a

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

which can grow up to long. Their color ranges from almost gray to a deep blue. It is somewhat distinctive for having a single long dorsal fin which leans back.

References

longidorsalis Fish described in 1993 Endemic fish of Mexico Freshwater fish of Mexico Taxa named by María de Lourdes Lozano-Vilano Taxa named by Salvador Contreras-Balderas Fish of North America becoming extinct since 1500 Taxonomy articles created by Polbot {{Cyprinodontiformes-stub