|Scientific Name:||Gambusia senilis Girard, 1859|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Reviewer(s):||Smith, K. & Darwall, W.R.T.|
|Facilitator/Compiler(s):||Hammerson, G.A. & Ormes, M.|
Listed as Near Threatened because extent of occurrence may be less than 20,000 sq km, area of occupancy may be less than 2000 sq km, and habitat quality/quantity and species distribution and abundance probably are declining as a result of ongoing habitat loss/degradation and effects of introduced fish species; however, the rate of decline is unknown, the species occurs in more than 10 locations, and distribution may not be severely fragmented, so the species does not fully meet the criteria for the Vulnerable category.
|Previously published Red List assessments:|
|Range Description:||Range includes the Devils River, Texas (formerly), and Rio Conchos and tributaries, Chihuahua and Durango, Mexico; also the endorheic Rio Sauz basin (Miller 2005, Page and Burr 2011). The species is widely distributed in the Rio Conchos drainage.|
Regionally extinct:United States
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is represented by a large number of occurrences in Mexico. The number of locations is uncertain but exceeds 10.|
Total adult population size is unknown but presumably exceeds 10,000.
Status is unknown, but the species may be secure due to its wide distribution (Minckley et al. 1991). Presumably the trend over the past 10 years or three generations has been relatively stable or declining, but the rate of decline is unknown. Three generations span fewer than 10 years.
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Habitat includes stream channels, edges, backwaters; springs, outflows, marshes; eurythermal (Minckley et al. 1991, Page and Burr 2011). Usually this species is collected in quiet, weed-choked surface waters. It is tolerant of wide variations in temperature, chemical conditions, and water flow, and clarity.|
|Movement patterns:||Not a Migrant|
|Major Threat(s):||Threats include habitat loss and degradation (e.g., dewatering of habitat) and adverse effects of introduced species (Jelks et al. 2008).|
|Conservation Actions:||Better information is needed on current distribution, abundance, threats, and population trend.|
|Citation:||NatureServe. 2014. Gambusia senilis. The IUCN Red List of Threatened Species 2014: e.T8896A18230910.Downloaded on 24 March 2018.|