|Scientific Name:||Cyprinodon eremus|
|Species Authority:||Miller and Fuiman, 1987|
Cyprinodon maclarius subspecies sonoytae Peterson, 1993
Cyprinodon macularius subspecies eremus Miller & Fuiman, 1987
|Red List Category & Criteria:||Endangered B1ab(iii,v)+2ab(iii,v) ver 3.1|
|Reviewer(s):||Smith, K. & Darwall, W.R.T.|
|Facilitator/Compiler(s):||Hammerson, G.A. & Ormes, M.|
This species is listed as Endangered because extent of occurrence may be less than 200 sq km, area of occupancy is less than or not much more than about 20 sq km, the species occurs in just a few locations, and the population is subject to ongoing declines resulting from habitat loss/degradation, non-native species, and unknown factors.
|Range Description:||Range includes Quitobaquito Spring (Gila River system) in Organ Pipe Cactus National Monument, Pima County, Arizona, and two segments of the Rio Sonoyta (Gulf of California basin), Sonora, Mexico (Echelle et al. 2000, Page and Burr 2011). Additional stocks of the Quitobaquito form occur in refugia outside the native range in Arizona.|
Native:Mexico; United States
|Range Map:||Click here to open the map viewer and explore range.|
Extant populations represent at least (and perhaps at most) three distinct occurrences (Hendrickson and Varela 1989, Echelle et al. 2000).
In the late 1990s, the estimated total population in the Quitobaquito spring complex averaged 9,556 individuals (Douglas et al. 2001). In two sampling points along the Rio Sonoyta, one in a river segment at least 3 km long and the other in a segment about 13 km long, Cyprinodon eremus comprised 15.1-15.9 percent of 636 and 447 fishes collected, respectively (Hendrickson and Varela 1989).
Trend over the past 10 years (three generations is less than 10 years) is uncertain but probably highly variable. Abundance in Quitobaquito Springs in recent years varied annually in response to unknown factors from fewer than 1,000 to nearly 10,000 individuals (Minckley and March 2009). Abundance index at Quitobaquito stayed within historical limits even during the water level problems of 2005-2009 (USFWS 2010). Relatively good condition of populations in Rio Sonoyta in 1989 was probably a short-lived response to recent, rare discharge (water flow) events (Hendrickson and Varela 1989).
|Habitat and Ecology:||Habitat includes springs (and highly modified interconnecting channels), marshes, lakes, moderately saline pools, and sluggish stream flows, usually over sand or mud (Minckley et al. 1991, Miller 2005, Minckley and Marsh 2009, Page and Burr 2011).|
|Use and Trade:||This species is not utilized.|
This species is relatively intolerant of competition and predation, and it is easily displaced by introduced fishes. Cyprinodon eremus coexists with Mosquitofish (Gambusia affinis) and Black Bullhead (Ameiurus melas) in the Rio Sonoyta. Mosquitofish are increasing there, perhaps at the expense of C. eremus; the impact of the bullheads is uncertain but they are probably a predator (Hendrickson and Varela 1989). Other threats in the Rio Sonoyta basin include groundwater pumping for agriculture and aerial spraying of pesticides (Hendrickson and Varela 1989). Sonoyta Pupfish is tolerant of a limited amount of nondestructive intrusion (e.g., swimming), but reproduction can easily be disrupted.
During 2005-2009, water level at Quitobaquito underwent a serious decrease that resulted in drastic conservation measures (see USFWS 2010 for summary) in order to restabilize the pond.
Introductions of Cyprinodon macularius (a close relative) into marginal, semi-natural, relatively stable habitats have not been especially successful; recovery planners should consider use of riverine habitat and manipulations of flows or other disturbances (Hendrickson and Varela 1989).
See Meffe and Vrijenhoek (1988) and especially Echelle et al. (2000) for a discussion of conservation genetics. Echelle et al. (2000) recommended that conservation management should not mix the Quitobaquito and Rio Sonoyta stocks, based on their long history of isolation and evidence of morphological divergence.
See Hendrickson and Brooks (1991) for information on transplantation efforts.
The streambed between the springhead and pond at Quitobaquito Spring in Organ Pipe Cactus National Monument recently was rebuilt to facilitate vegetation control; pupfishes reoccupied the springrun within 2 weeks (USFWS 1990).
Exotic fishes and predators need to be excluded from habitat. Excessive groundwater pumping should be prevented. The habitat needs to be protected from pesticide incursion.
|Citation:||NatureServe 2014. Cyprinodon eremus. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 30 August 2015.|
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