|Scientific Name:||Notropis jemezanus|
|Species Authority:||(Cope, 1875)|
Alburnellus jemezanus Cope, 1875
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer(s):||Smith, K. & Darwall, W.R.T.|
|Facilitator/Compiler(s):||Hammerson, G.A. & Ormes, M.|
This species is listed as Near Threatened because its extent of occurrence exceeds 20,000 sq km, the number of locations probably exceeds 10, range is not severely fragmented, and area of occupancy is unknown. However, within the species' small, shrinking range, distribution and abundance evidently are still declining due to ongoing threats to habitat, so the species warrants continued conservation attention..
|Range Description:||Range includes the Rio Grande drainage, from just above the mouth to the Pecos River (north in Pecos River to Sumner Lake, New Mexico; formerly north to Santa Rosa) and (formerly) Rio Grande, New Mexico (where now extirpated); absent from large sections of the Rio Grande and Pecos River in western Texas; occurs in Rio San Juan, Rio Salado, and Rio Conchos, Mexico (Sublette et al. 1990, Platania and Altenbach 1998, Miller 2005, Page and Burr 2011).
Sampling between the Fort Sumner Irrigation District Dam and Brantley Reservoir in the Pecos River, New Mexico, between 1992 and 2002 revealed that N. jemezanus composed 11 percent of all fish collected; this area harbours the species' largest known population and is the last remaining population within the Pecos River basin (Hoagstrom and Brooks 2005).
Hubbs et al. (1977) reported the absence of N. jemezanus from middle Rio Grande between El Paso and Presidio, Texas. In the Rio Grande, Edwards et al. (2004) reported that this species had not been collected below Amistad Reservoir in the last 10 years. These sections encompass the majority of the Rio Grande along the Texas-Mexico border.
Native:Mexico; United States
|Range Map:||Click here to open the map viewer and explore range.|
This species is represented by a relatively small number of extant occurrences (subpopulations) and locations (as defined by IUCN). The Texas Natural History Collections (1997) mapped 65 collection locations, including 41 in the Rio Grande in Texas, two in the Pecos River in Texas, 10 in the Pecos River drainage in New Mexico, four in the Rio Grande in New Mexico, four in the Rio Conchos, two in the Rio Salado, and two in the Rio San Juan. However, the species no longer occurs in many areas, including the New Mexican Rio Grande, much of the Rio Grande in Texas, and a portion of the Pecos River above Sumner Lake (New Mexico Department of Game and Fish 1996; Platania and Altenbach 1998; Edwards et al. 2002, 2004; Hubbs et al. 2008).
Total adult population size is unknown but presumably exceeds 10,000. Regularly collected, but uncommon in the Rio Grande downstream of the confluence with the Rio Conchos; extirpated from the New Mexican Rio Grande; generally uncommon to rare within the Pecos River in New Mexico, currently persists from Old Fort State Park downstream to about Brantley Reservoir (New Mexico Department of Game and Fish 1996).
Distribution and abundance have declined over recent decades (New Mexico Department of Game and Fish 1996; Platania and Altenbach 1998; Edwards et al. 2002, 2004; Hubbs et al. 2008). The species is extirpated in the New Mexican Rio Grande, last collected there in 1949.
Trend over the past 10 years or three generations is uncertain, but distribution and abundance probably are still declining. Rate of decline is unknown. Three generations span fewer than 10 years.
|Habitat and Ecology:||Habitat includes runs and flowing pools of large open weedless rivers and large creeks with bottoms of rubble, gravel, and sand, often overlain with silt (Lee et al. 1980, Sublette et al. 1990, Page and Burr 2011).|
|Major Threat(s):||Primary threats are dewatering and modification of natural flow regimes. Potential threats include contaminants and non-native competitors/predators. Irrigation withdrawals and the construction of mainstem dams altered the Rio Grande prior to 1930 and probably reduced populations. Drought and increased water withdrawal after 1950 periodically dried extensive reaches of the Rio Grande and probably eliminated the remaining small populations.|
|Conservation Actions:||Better information on abundance and population trend is needed.|
|Citation:||NatureServe 2014. Notropis jemezanus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 23 May 2015.|
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