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The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: Pahrump Poolfish

Synonyms and Other Names: Pahrump killifish

Taxonomy: available through www.itis.gov

Identification: Empetrichthys latos is a small slender fish with a broad mouth, short slender head, and no pelvic fins (U.S. Fish and Wildlife Service 1979). It is greenish at the dorsum (back) which fades to silver-green ventrally (towards the belly), with a faint axial streak, and during mating males are washed with a light blue tint (U.S. Fish and Wildlife Service 1979). It usually has 31-32 scales in the lateral series and 12 or 13 anal rays (La Rivers 1994).

This species was once represented by three subspecies: Empetrichthys latos latos, Empetrichthys latos concavus, and Empetrichthys latos pahrump; two are extinct, and only E. l. latos remains (U.S. Fish and Wildlife Service 1979).

Size: Up to 8 cm (U.S. Fish and Wildlife Service 1979)

Native Range: It has been extirpated from its native range in Manse Spring in Pahrump Valley, Nevada, USA.

Each subspecies was confined to an isolated spring in Pahrump Valley, Nye County, Nevada, where it was the only native fish. The Pahrump Poolfish E. l. latos disappeared from Manse Springs in August 1975 and now exists only outside the Pahrump Valley in transplanted locations (U.S. Fish and Wildlife Service 1979, Page and Burr 1991).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Native range data for this species provided in part by NatureServe

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology: Empetrichthys latos uses all areas of its desert spring habitat, with adults more commonly found in the deeper open waters and juveniles found in shallower vegetated areas near the water’s surface (U.S. Fish and Wildlife Service 1979). It is omnivorous and will eat a wide variety of available plants and small animals (U.S. Fish and Wildlife Service 1979). After breeding, which occurs throughout the year under favorable conditions, females seek seclusion to lay their eggs (U.S. Fish and Wildlife Service 1979).

Means of Introduction: This species was intentionally stocked to establish refuge populations for preservation of the species. The transplant to Corn Creek Spring took place in 1971 and involved 29 fish; Shoshone Ponds complex, a site created by the US Bureau of Land Management, was stocked in 1972 with 16 fish from Corn Creek or Manse Ranch Spring (an additional 50 fish were transplanted to the site in 1976); Spring Mountain Ranch State Park was stocked in 1983 with an unrecorded number of fish (Pister 1974, U.S. Fish and Wildlife Service 1979, Minckley et al. 1991). The Nevada Department of Fish and Game was instrumental in at least two of these introductions (Pister 1974).

Status: The species is established at Corn Creek Spring, the Shoshone Ponds complex, and Spring Mountain Ranch State Park (Minckley et al. 1991); populations also are established and stable at Chimney Springs, Hot Creek, and Sodaville Springs as of 1992 (Clemmer, personal communication). In 1989, Shoshone Ponds had approximately 450 fish (Bureau of Land Management, Ely, records). Several transplants have failed (Minckley et al. 1991). Soltz and Naiman (1978) reported that relatively large reproducing populations of Pahrump Poolfish have been established in ponds at Corn Creek and in an isolated canyon above the Colorado River. They indicated that a third population was established in an artificial refugium in Ash Meadows but that it died out in 1977.

Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

Remarks: This species is federally listed as an endangered species (U.S. Fish and Wildlife Service 1993). The introduction of other fishes into its native spring habitat contributed to the decline of Empetrichthys latos. For instance, Deacon et al. (1964) reported that the establishment of goldfish (Carassius auratus) in Manse Spring resulted in population depression.

Other Resources:
Clemmer, G. - Nevada Natural Heritage Program, Carson City, NV.

Deacon, J.E., C. Hubbs, and B.J. Zahuranec. 1964. Some effects of introduced fishes on the native fish fauna of southern Nevada. Copeia 1964(2):384-388.

La Rivers, I. 1994. Fishes and fisheries of Nevada. New reprinted edition. University of Nevada Press, Reno, NV.

Lee, D.S., C.R. Gilbert, C.H. Hocutt, R.E. Jenkins, D.E. McAllister, and J.R. Stauffer, Jr. 1980. Atlas of North American freshwater fishes. North Carolina State Museum of Natural History, Raleigh, NC.

Minckley, W.L., G.K. Meffe, and D.L. Soltz. 1991. Conservation and management of short-lived fishes: the cyprinodontoids. Pages 247-282 in Minckley, W.L., and J.E. Deacon, eds. Battle against extinction: native fish management in the American west. University of Arizona Press. Tuscon, AZ.

Page, L.M., and B.M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. The Peterson Field Guide Series, volume 42. Houghton Mifflin Company, Boston, MA.

Pister, E.P. 1974. Desert fishes and their habitats. Transactions of the American Fisheries Society 103(3):531-540.

Soltz, D.L., and R.J. Naiman. 1978. The natural history of native fishes in the Death Valley system. Science Series 30. Natural History Museum of Los Angeles County, Los Angeles, CA.

U.S. Fish and Wildlife Service. 1979. Pahrump killifish recovery plan. U.S. Fish and Wildlife Service, Denver, CO. 37 pp.

U.S. Fish and Wildlife Service. 1993. Endangered and threatened wildlife and plants. 50 CFR 17.11 & 17.12. Federal Register, August 23, 1993. U.S. Department of the Interior, Washington, DC. 40 pp.

Williams, J E., D.W. Sada, C.D. Williams, and other members of the Western Division of Endangered Species Committee. 1988. American Fisheries Society guidelines for introductions of threatened and endangered fishes. Fisheries 13(5):5-11.

Author: Reaver, K.M., Fuller, P.

Peer Review Date: 12/5/2003

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.