Girardinichthys viviparus

Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
Girardinichthys viviparus
English Name: 
Chapultepec Splitfin
Mexican Name: 
Mexclapique
Original Description: 

  BUSTAMANTE y SEPTIÉN, M. (1837): Descripción del Mexcalpique (Cyprinus viviparus). El Mosaico Mexicano vo 2: p 116

Holotype: 

no Holotype deposited 

Terra typica: 

The terra typica has been given with Mexico City.

Etymology: 

  This species name is derived from the Latin and means "livebearing". It was the first species of Cyprinodonts, where livebearing has been observed.

Synonyms: 

Cyprinus viviparus   Bustamante, 1837
Lucania sp.   Girard, 1859
Girardinichthys innominatus   Bleeker, 1860 
Limnurgus variegatus   Günther, 1866 
Mollienesia sp.   Gill, 1882 
Lucania richi   Goode, 1891
Characodon geddesi   Regan, 1904
Limnurgus innominatus   Regan, 1907

Distribution and ESU's: 

  The Chapultepec Splitfin is endemic to the Mexican federal states Distrito Federal and México and is the only Goodeid species native to Mexico City. In the ancient times of Tenochtitlán, the capital of the Aztec empire, it must have had occupied the complete extension of the large Lago de Texcoco and its connected waterbodies in the endorheic valley of México, which included the lagos de Xochimilco, Xaltocán and Chalco and the Laguna Zumpango. Miguel Bustamante y Septién (1837) mentioned that this species was an exceedingly common fish in the lagoons and irrigation channels of Mexico City. Nowadays, after hundreds of years of draining wetlands and lakes to allow for the enormous expansion of Mexico City, Girardinichthys viviparus can just be found in the remnants of the former huge lakes. It has persisted only in the three artificial lakes in the Parque de Chapultepec inside Mexico City, with a stronghold in the Lago Mayor, with small numbers in the lakes Zumpango and Xochimilco, and in moderate numbers near the airport at Alameda Oriente, which belongs to the former Lake of Texcoco. Through the artificial Canal Río Cuautitlán from the Zumpango lagoon, the species managed to reach the Río Tula system and by that way the Presa Requena in Hidalgo, where it is now said to be extinct. Robert Rush Miller reported the species in 1977 also from the state of Mexico from ditches S of San Juan Teotihuacán about 25km NE of the Lake of Texcoco and a recent found (2017) was made in a small dam near Nopaltepec 40km E of the Zumpango lagoon, that drains into the Canal San Lorenzo, that lateron merges into the Gran Canal de Desagüe, the connection between the Lago de Texcoco and the Laguna Zumpango. In 2008 (Miranda et al.), the Mexclapique was found in high abundance in the Laguna Tecocomulco about 80km E of Mexico City in the basin of the Río Pánuco in the state of Hidalgo. This stock is introduced and the species not native to this lake. No subpopulations are distinguished. The underlined names are the ones officially used by the Instituto Nacional de Estadística y Geografía; nevertheless, other ones might be more often in use or better known and therefore prefered.

 

  ESU ist short for Evolutionarily Significant Unit. Each unit expresses an isolated population with different genetic characteristics within one species.  ESU's can be defined by Molecular genetics, Morphology and/or Zoogeography and help in indicating different phylogenetic lineages within a species. The abbreviation for an ESU is composed of the first 3 letters of the genus, followed by the first 2 letters of the species name and an ongoing number in each species.

 

  In Girardinichthys viviparus we do not distinguish any ESU, so all populations belong to Girvi1.

 

  Maximum Extent of Occurence of Girardinichthys viviparus:

Maximum EOO of Girardinichthys viviparus

Status : 

  International Union for Conservation of Nature (IUCN): critically endangered

 

  Conservation status and population trends of Mexican Goodeids (Lyons, 2011): critically endangered/stable? – Historically, this species was endemic to and abundant in the many lakes and wetlands of the endorheic Valley of Mexico, where Mexico City is located (Miller at al. 2005). Construction of a canal to drain the Valley allowed the species to colonize a small spring along the Tula River in the headwaters of the Pánuco River on the Atlantic slope where the species still remains in small numbers (Edmundo Díaz-Pardo, Universidad Autónoma de Querétaro, Querétaro, Mexico, personal communication). The drainage of the Valley coupled with the rapid expansion of Mexico City led to a drastic decline in the distribution and abundance of G. viviparus. During the 20th century, the species was eliminated from Lake Texcoco and Lake Chalco and became rare in Lake Xochimilco and Lake Zumpango, all of which have become greatly reduced in size, highly polluted, and dominated by non-native fish species (Domínguez-Domínguez et al. 2005b). Despite poor environmental conditions, the Xochimilco and Zumpango populations have managed to survive up to the present. The best remaining population is in the artificial Lake Mayor in Chapultepec Park in downtown Mexico City. This population persists in moderate numbers despite poor water quality, but it is vulnerable to drainage of the lake for maintenance.

 

  NOM-059-SEMARNAT-2010: Categoría de riesgo (Category of risk): P - En Peligro de Extinción (in danger of extinction)

Habitat: 

This species inhabits quiet water of lakes, ponds, canals and ditches over mud substrate. It prefers clear to murky water and depths between 0.3 and 0.6m. Vegetation is abundant, mainly green algae, Potamogeton, water hyacinths, Lemna and Chara.

Lago Mayor I

Lago Mayor II

Laguna Tecocomulco I

Laguna Tecocomulco II

Biology: 

According to Díaz Pardo and Ortíz Jiménez (1986), the reproduction occurs continuously from at least February to October as indicated by captures of newborn young and individuals 8 to 14mm SL from February to May, with young appearing into October.

Diet: 

S.E. Meek noted a not-coiled intestinal canal, about the length of the body and small, pointed teeth, all indicates of a carnivorous nutrition. The cleft is nearly vertical, so this species might be specialized in feeding from a special kind of small invertebrates (Copepods?).

Size: 
The maximum known SL is 65mm (Miller et al, 2005).
Colouration: 

Males are silvery gray, marbled sligthly blackish-gray. The unpaired fins are dark, becoming darker at the edge and completely black in dominant males. During courtship the males become totally blackish to black. The paired fins are clear. Females are silvery-gray with the upper half of the body darker, the venter brighter. Sometimes, females show a gravity spot. The fins are clear to somehow dusky-grayish. Females show an indefinite number of dusky bars on the caudal peduncle and the upper half of the body, fading anteriorly. These bars are only sligthly darker than the body sides and sometimes not clearly visible. A bluish glimmer can be seen with some specimens.

Remarks: 

The Mexcalpique inhabited originally the endorheic basin of the Lago de Texcoco. Most parts of this Lake disappeared during the last decades, and with this parts disappeared also Girardinichthys viviparus. Miller reported 2005 (denoting that he died in 2003, but his book about Mexican fish had been published posthum), that through a canal, this species reached the Río Tula basin, where it could be found now in the Laguna de Zumpango. He reported this species also from collections in ditches south of San Juan Teotihuacán in 1977 and a small population persisting in Lago Xochimilco (2003).

Meanwhile, a study from Salgado et al (2004) revealed that in 2 of 5 known habitats, including the Laguna de Zumpango and the Requena Reservoir, this species has disappeared again and has survived only in the three lagos de Chapultepec in Mexico City. Further examinations in this 3 habitats showed a different abundance and threat of the species. In Lago Viejo, the situation was best with about 20 specimens per m² and no parasites. In Lago Menor, this species has been infected with Lernaea (about 48% of the specimens). The abundance has been about 15 specimens per m². The worst situation has been in Lago Mayor with only 2 specimens per m² and nearly all fish infected with Lernaea and Bothriocephalus acheilognathi, a tapeworm typical for asian cyprinids. Lagos Menor and Mayor had been populated with Cyprinus carpio (probably the reason for the infection with the tapeworrm and Lernaea), Lago Mayor with Tilapia, too.

In Viviparous fishes (Uribe & Grier, 2005) Domínguez et al. published results of "recent annual systematic samples", where this species has been found in the lagos de Xochimilco and Zumpango, but very rarely, and the most likely largest population in the Lago Mayor. 

 

In 2008, Miranda et al. reported about a high abundance of Girardinichthys viviparus in the Lago de Tecocomulco, northeastern of México City, where it hasn't been reported before. It might have been overlooked there, though this lake has been studied well. Another possibility may have been the introduction by man. 

 

Girardinichthys viviparus has been the first cyprinodontiform fish, where livebearing has been observed, probably as early as 1769. Following T. Gill - who translated a letter in 1882 from Don Joseph Anthony de Alzate y Ramirez, who observed the transit of the Venus in 1769 - this Don Alzate forwarded some preserved viviparous scaly fishes in 1772 to the Royal Academy of Sciences in Paris. Gill translated further, that Don Alzate had told the academy before about this odd species, he stated the locality of this new species with Mexico City and he wrote the following most interesting lines: "If you press the belly with your fingers, you force out the fry before their time, and upon inspecting them through the microscope, you may discern the circulation of blood, such as it is to be when the fish is grown up. If you throw these little fishes into water, they will swim as well as if they had been long accustomed to live in that element." Doubtlessly, this fish had been Girardinichthys vivparus.

 

Guenther (1866) had chosen the scientific name Limnurgus variegatus to "purge the barbarous" name Girardinichthys innominatus, given by Bleeker six years before. This is of course not legimitated. However, the species had been already described in 1837 by S. Bustamante as Cyprinus viviparus, so this species name had to be accepted finally.

Locations