Empetrichthys latos

Subspecies latos is the sole extant member of the genus Empetrichthys; the other species (E. merriami, Ash Meadows poolfish) and the other subspecies of E. latos are extinct. The species of Crenichthys and Empetrichthys were removed from the family Cyprinodontidae (order Atheriniformes) and placed in the family Goodeidae (order Cyprinodontiformes) by Parenti (1981). Crenichthys and Empetrichthys were assigned to the family Empetrichthyidae by Miller and Smith (1986). The 1991 AFS checklist (Robins et al. 1991) retained these genera in the Cyprinodontidae, pending confirmatory evidence for change based on additional character suites. MtDNA data of Grant and Riddle (1995) indicate that the phylogenetic affinity of Crenichthys and Empetrichthys is with the family Goodeidae rather than with the representative fundulines, poeciliids, or cyprinodontines.

Extirpated from native range in three springs in Pahrump Valley, Nevada; introduced populations now exist in a few warm springs elsewhere in Nevada; one of the three populations is stable; populations face ongoing threats from introduced non-native aquatic species and losses of habitat due to probable increases in human uses of groundwater.

This species historically was restricted to 3 separate springs in Pahrump Valley, southern Nye County, Nevada; now it exists only where introduced outside the Pahrump Valley (Page and Burr 2011). Formerly it occurred in Raycraft Ranch Spring (subspecies concavus) and Pahrump Springs (subspecies pahrump). Subspecies latos: is extirpated in its native habitat at Manse Ranch Spring (dewatered). In the early 2000s, transplanted populations of subspecies latos occurred at three locations: Corn Creek Springs on the Desert National Wildlife Refuge, Clark County; Shoshone Springs (Ponds), Spring Valley, White Pine County (on BLM's Shoshone Ponds Natural Area); and an irrigation reservoir, fed by Sandstone Spring, at Spring Mountain Ranch State Park, Clark County (Minckley et al. 1991; USFWS 1993, 2004). All are on public lands.

This species is represented by just a few occurrences (subpopulations).

E. l. pahrump is extinct due to groundwater pumping; E. l. concavus is extinct due to groundwater pumping and springhead filling (Minckley et al. 1991), and E. l. latos was extirpated in native range when its spring dried up as a result of excessive groundwater pumping for irrigation. The Corn Creek population was extirpated as a result of an illegal introduction of non-native crayfish, with non-native goldfish possibly also contributing to the decline (USFWS 2004). Illegal introductions of nonnative aquatic species currently pose the most significant threat to the existence of this species.

Long-term declines in spring flows due to groundwater pumping from areas surrounding existing poolfish habitat remain a threat to all the populations. Threats to water sources necessary for poolfish habitat have been minimized to the extent possible by the managing Federal and State agencies (USFWS 2004). However, it is likely that demands on the groundwater system to accommodate extensive human population growth and development in southern Nevada could threaten the future existence of the poolfish.

Recent residential development in and around the native habitat at Manse Ranch continues to modify the native habitat, and future residential and commercial development in the Pahrump Valley may limit the available water resources and preclude the opportunity to re-establish a poolfish population in this location (USFWS 2004).

Poolfish populations at Corn Creek and Shoshone Ponds Natural Area are vulnerable to vandalism (USFWS 2004).

Jelks et al. (2008) categorized this species as Endangered, due to present or threatened destruction, modification, or reduction of habitat or range; other natural or anthropogenic factors that affect a taxon's existence, including impacts of nonindigenous organisms, hybridization, competition, and/or predation; and restricted range.