|Scientific Name:||Cyprinodon bovinus|
|Species Authority:||Baird & Girard, 1853|
|Red List Category & Criteria:||Vulnerable D2 ver 3.1|
|Reviewer/s:||Smith, K. & Darwall, W.R.T.|
|Facilitator/s:||Hammerson, G.A. & Ormes, M.|
This species is listed as Vulnerable because its extent of occurrence and area of occupancy are less than 10 sq km, the species occurs in only one location, and species faces future threats from non-native fishes and declining spring flows. The population (estimated to be fewer than 10,000 adults) appears to be relatively stable. Evidence of a decline would put this species in the Critically Endangered category.
|Range Description:||Historical range included the lower portion of Leon Creek and Diamond-Y Spring, Pecos County, Texas. Population at the type locality (Leon Springs) is extirpated (Echelle et al. 1987, Page and Burr 2011).|
|Range Map:||Click here to open the map viewer and explore range.|
This species is represented by a single occurrence.
Population in Diamond Y Draw has been estimated at fewer than 10,000 adults (Echelle pers. comm. in Garrett et al. 2002). This pupfish is common in an extremely small area (Page and Burr 2011).
Small surviving population was stable in the 1980s (USFWS 1990).
Trend over the past 10 years or three generations is uncertain but probably relatively stable.
|Habitat and Ecology:||Habitat consists of shallow saline springs, pools, and outflow streams. This fish is most abundant in quiet water near edges of pools, particularly where there are minimal growths of algae (Lee et al. 1980). Springs are typically quite hard, with high levels of silica, sulphates, and chlorides (Lee et al. 1980). Permanent water exists as two semi-isolated reaches in Leon Creek, which originates in seeps and flows 1 km to join another 1-km-long outflow from Diamond-Y Spring; a combined permanent flow then passes another kilometre or so and percolates into the ground; the channel then becomes ill-defined and dry for about 2 km, then water reenters from seeps and springs to form a second 2.7-km reach of perennial flow that ends in two livestock watering tanks; the extent of water in this system varies with climatic conditions; salt encrustations are common along the banks, which are vegetated by sedges and other low marshland plants (Minckley et al. 1991). Spawning occurs in shallow, slow-current areas (Kennedy 1977).|
The major threats to this species include habitat loss from declining springflows and reduced surface waters, competition with introduced species, and hybridization with introduced fishes (Texas Parks and Wildlife Department).
Most of the habitat at Leon Springs was inundated by impoundment in 1918; by 1958 the springs went dry due to overdraft of ground water and lowered water table (Echelle et al. 1987). Spring flow has been decreasing and the spring may dry up if pumping continues at the present rate (Matthews and Moseley 1990). Also, activity in the nearby (upstream) oil and gas field poses a threat, as does the ease with which non-native fishes could be introduced.
The species was regarded as extinct in publications of the late 1950s and early 1960s; rediscovered and redescribed in the mid-1960s and early 1970s, a period when the introduced Cyprinodon variegatus became established and hybridized with C. bovinus. C. variegatus and hybrids reportedly were eliminated by intensive management in the 1970s (see Minckley et al. 1991), but Echelle and Echelle (1997) found genetic introgression of the entire wild population by C. variegatus, probably due to a recent introduction of C. variegatus. Restricted habitat allows for little resiliency to outside pressures.
|Conservation Actions:||Exclusion/removal of Cyprinodon variegatus from Lake Balmorhea is important. See recovery plan (1985). Systematic genetic monitoring is needed (Echelle and Echelle 1997) Population is monitored annually.|
|Citation:||NatureServe 2013. Cyprinodon bovinus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 12 December 2013.|
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