The Chapultepec splitfin (''Girardinichthys viviparus''), known locally as ''mexcalpique'', is a critically endangered species of fish in the family

Goodeidae Goodeidae is a family of teleost fish endemic to Mexico and some areas of the United States. Many species are known as splitfins. This family contains about 50 species within 18 genera. The family is named after ichthyologist George Brown Goode ...

. It is

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 Mexico and was originally restricted to lakes and wetlands in the

Valley of Mexico The Valley of Mexico ( es, Valle de México) is a highlands plateau in central Mexico roughly coterminous with present-day Mexico City and the eastern half of the State of Mexico. Surrounded by mountains and volcanoes, the Valley of Mexico wa ...

, including

Lake Texcoco Lake Texcoco ( es, Lago de Texcoco) was a natural lake within the "Anahuac" or Valley of Mexico. Lake Texcoco is best known as where the Aztecs built the city of Tenochtitlan, which was located on an island within the lake. After the Spanish con ...

. Through man-made channels it was able to spread to the upper

Pánuco River The Pánuco River ( es, Río Pánuco, ), also known as the ''Río de Canoas'', is a river in Mexico fed by several tributaries including the Moctezuma River and emptying into the Gulf of Mexico. The river is approximately long and passes throug ...

basin (notably

Tula River The Tula River ( es, Río Tula) is a river in Hidalgo State in central Mexico, and a tributary of the Moctezuma River. Geography It runs through the city of Tula de Allende and begins as a drainage channel for the Valley of Mexico, which contain ...

and associated reservoirs). Most native populations disappeared as they were at or near

Mexico City Mexico City ( es, link=no, Ciudad de México, ; abbr.: CDMX; Nahuatl: ''Altepetl Mexico'') is the capital and largest city of Mexico, and the most populous city in North America. One of the world's alpha cities, it is located in the Valley o ...

, with the waters either being

reclaimed Land reclamation, usually known as reclamation, and also known as land fill (not to be confused with a waste landfill), is the process of creating new Terrestrial ecoregion, land from oceans, list of seas, seas, Stream bed, riverbeds or lak ...

, drained, heavily polluted or infested with

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

. Today the Chapultepec splitfin is only known to survive in three lakes (Viejo, Menor and Mayor) in the

Chapultepec Chapultepec, more commonly called the "Bosque de Chapultepec" (Chapultepec Forest) in Mexico City, is one of the largest city parks in Mexico, measuring in total just over 686 hectares (1,695 acres). Centered on a rock formation called Chapultep ...

park of Mexico City,

Lake Xochimilco Lake Xochimilco (; nah, Xōchimīlco, ) is an ancient endorheic lake, located in the present-day Borough of Xochimilco in southern Mexico City. The lake is within the Valley of Mexico hydrological basin, in central Mexico. History Geolo ...

Lake Zumpango Lake Zumpango was an endorheic lake formerly located in the Valley of Mexico. It was important area for Mesoamerican cultural development in central Mexico. The endorheic basin located in the north of State of Mexico, in the borough of municipa ...

, Laguna de Tecocomulco northeast of the City where perhaps introduced, and parts of the Pánuco River basin. Most of these remaining populations are small. This species was originally described as ''Cyprinus viviparus'' in 1837 by Miguel Bustamante y Septién with the type locality given as "Mexico". In 1860 Pieter Bleeker raised the genus ''

Girardinichthys ''Girardinichthys'' is a genus of splitfins that are endemic to Mexico. These highly threatened fish are native to the upper Lerma and Balsas basins, as well as water systems in the Valley of Mexico. Through man-made channels ''G. viviparus'' h ...

'' with a new species ''Girardinichthys viviparus'' as its

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

, this subsequently proved to be a

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

of ''Cyprinus viviparus''.

References

Girardinichthys Freshwater fish of Mexico Fish described in 1837 Taxonomy articles created by Polbot {{Cyprinodontiformes-stub