Critically Endangered
Devils Hole pupfish
Cyprinodon diabolis
Devils Hole pupfish is a ray-finned fish in the family Cyprinodontidae (order Cyprinodontiformes) — Cyprinodon diabolis, recorded as Critically Endangered and tied to United States.
Appearance
Males and females differ in coloration. Males are overall dark brown with metallic blue on their sides. Iridescence is particularly pronounced on the opercles (gill covers) that have a violet sheen on their posterior side.
The Devils Hole pupfish is the smallest pupfish species in the genus Cyprinodon, with lengths up to 30 mm (1.2 in).
The average length is 23 mm (0.9 in). It is a small fish, with maximum lengths of up to 30 mm (1.2 in).
It was first described as a species in 1930 and is most closely related to C. Nevadensis and the Death Valley pupfish (C. Salinus).
Range and habitat
Devils Hole and the pupfish are located in the Amargosa Desert ecosystem, in the Amargosa Valley, of southwestern Nevada, US, east of Death Valley and the Funeral Mountains and Amargosa Range. The Amargosa River is part of Devils Hole and the region's aquifer hydrology. Devils Hole "may be the smallest habitat in the world containing the entire population of a vertebrate species".
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
The three most common food items for each season by frequency of occurrence were: Spring (March through May): inorganic particulate matter (83%), diatoms (75%), and Spirogyra (58%) Summer (June through August): inorganic particulate matter (79%), Spirogyra (46%), and diatoms (46%) Autumn (September through November): inorganic particulate matter (95%), Spirogyra (74%), and Hyalella azteca (33%) Winter (December through February): inorganic particulate matter (100%), diatoms (91%), and ostracods (45%) As Spirogyra was mostly found undigested in the stomach, the authors hypothesized that it was not important as a food resource, but rather as a foraging substrate. The pupfish consumes nearly every available food resource at Devils Hole, among them beetles, snails, algae, and freshwater crustaceans, with diet varying throughout the year.
Females produce few eggs and the survivorship from egg to adult is low. A small, shallowly submerged rock shelf provides critical feeding and spawning habitat for the pupfish.
In crisis
Individuals live 10–14 months. After the groundwater withdrawal was limited, its population rebounded, but experienced a second decline from 1995 onward. Isolation over the course of thousands of years has led the Devils Hole pupfish to become what are believed to be one of the most inbred vertebrates on Earth, and the resulting high mutation load and genetic instability remains a potential long-term threat to the species as a whole.
Due to the fear of extinction in the 1960s and 1970s, several measures were taken to create multiple populations of the pupfish outside of Devils Hole to safeguard the species, that is known as ex situ conservation. From the founding population of twenty-five fish, it remained at several dozen individuals until a power failure in August 1984 disrupted the water flow, reducing the population to seven.
Devils Hole pupfish is Critically Endangered 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 Devils Hole pupfish, Wikidata item Q301137. 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.
