Extinct in the Wild
Monterrey platyfish
Xiphophorus couchianus
Monterrey platyfish is a livebearer in the family Poeciliidae (order Cyprinodontiformes) — Xiphophorus couchianus, recorded as Extinct in the Wild.
Appearance
The Monterrey platyfish is a dull-colored fish, appearing not unlike a female guppy. It has large black blotching, unlike the typical, unspotted form from the Huasteca Canyon.
Sexual dimorphism is moderate, the male Monterrey platyfish growing to a maximum overall length of 4 cm (1.6 in) and the female 6 cm (2.4 in).
Range and habitat
A live-bearer, it was native to a very small section of the San Juan River system (itself part of the Rio Grande basin) in the vicinity of the city of Monterrey, Mexico.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Breeding
Livebearers drop free-swimming young. Many species occupy springs, lakes, or ditches with little room to retreat.
Small desert or forest fishes in this order live in water that can vanish. The egg bank, if there is one, is the only reserve.
In crisis
IUCN lists the Monterrey platyfish as "extinct in the wild". Although once found more widely in the region of Monterrey, populations have been lost to urban sprawl, with water habitats either drying up (due to land reclamation and water extraction) or being heavily polluted. Introduced species is another threat.
"Safety populations" are maintained in captivity by the Centro de Resguardo para Peces en Peligro de Extinción at Universidad Autónoma de Nuevo León, Mexico (maintaining both the typical form and X. Aff. Couchianus), Xiphophorus Genetic Stock Center at Texas State University, United States (maintaining typical form), via the American Livebearer Association that mostly includes private aquarists in the United States (maintaining typical form), and by XNP conservation project members, that include public aquariums, universities and private aquarists in several European countries and the United States (maintaining typical form). The Monterrey platyfish shares the title as northernmost naturally distributed Xiphophorus with the closely related northern platyfish (X. Gordoni) and marbled swordtail (X. Meyeri), that are two species that also are restricted to northeastern Mexico and seriously threatened.
Monterrey platyfish is Extinct in the Wild on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Monterrey platyfish, Wikidata item Q2170401. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
