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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: Virgin Spinedace

Synonyms and Other Names: Big Spring spinedace, Virgin River spinedace, Colorado River spinedace

Taxonomy: available through www.itis.gov

Identification: La Rivers (1962); Page and Burr (1991). Two subspecies: L. m. pratensis, Big Spring spinedace, and L. m. mollispinis, Virgin River spinedace (U.S. Fish and Wildlife Service 1993d). Maximum size: 15 cm.

Native Range: L. m. pratensis: Meadow Valley Wash and Panaca Spring, Lincoln County, Nevada (U.S. Fish and Wildlife Service 1993d). L. m. mollispinis: Virgin River system, Utah, Nevada, and Arizona (Page and Burr 1991).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

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

Means of Introduction: Lepidomeda m. pratensis was transplanted for the purpose of preserving a threatened species. Larval fish from the plunge pool below the falls of Meadow Valley Wash were transplanted above the falls in 1980. Seventy-five fish were moved to Shoshone Pond Resource Area in July 1987 as an emergency protective measure after largemouth bass were discovered in Meadow Valley Wash. Six individuals were recovered in August 1989, none in July 1991 (U.S. Fish and Wildlife Service 1993d; Bureau of Land Management, Ely, records). The occurrence of L. m. mollispinis in Lake Mead, Nevada, was the result of bait bucket introductions of fish taken from the Santa Clara River in Utah (La Rivers 1962).

Status: In Nevada, Lepidomeda m. pratensis is established above the falls of Meadow Valley Wash; the population introduced to Shoshone Pond Resource Area is considered extirpated (U.S. Fish and Wildlife Service 1993d; Bureau of Land Management, Ely, records). The subspecies L. m. mollispinis was reported from Lake Mead, Nevada (La Rivers 1962); there is no evidence that it ever became established at that site.

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: Hendrickson and Brooks (1991) included the subspecies L. m. pratensis in their list of native southwestern fishes transplanted for conservation purposes. These researchers indicated that the fish was stocked once, successfully, but they did not provide details. The Big Spring spinedace is listed as a federally threatened subspecies (U.S. Fish and Wildlife Service 1993a). Prior to the elimination of the U.S. Fish and Wildlife Service candidate species list, the Virgin River spinedace was under review for Federal listing as an endangered or threatened species (U.S. Fish and Wildlife Service 1994a). It is not known whether this fish occurred above the waterfalls of Meadow Valley Wash (Nevada) prior to the transplant (U.S. Fish and Wildlife Service 1993d).

Other Resources:

Author: Nico, L.

Peer Review Date: 6/15/2004

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.