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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: Mesa Silverside

Taxonomy: available through www.itis.gov

Identification: Barbour (1973) provided a key to members of the genus.

Size: 9.1 cm SL.

Native Range: Central Mexico, Lago de Chapala and the Valley of Mexico (Barbour 1973; Contreras and Escalante 1984).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

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

Means of Introduction: Intentionally stocked by the Mexican federal government into two Rio Grande reservoirs, apparently with the hope of establishing a population that would serve as a source of food for local human residents (Courtenay and Hensley 1979a; Contreras and Escalante 1984). Introductions were made in the form of millions of fertilized eggs taken from Lake Chapala, Mexico (Courtenay and Hensley 1979a; C. Hubbs, personal communication to Courtenay; Courtenay, personal communication).

Status: The species failed to become established (Courtenay and Hensley 1979a; Contreras and Escalante 1984).

Impact of Introduction: Unknown (Contreras and Escalante 1984).

Remarks: There is some confusion concerning the Texas Chirostoma record and the species' true identity. The original information on the stocking apparently came from a Mexican news report that mentioned the release of 18 million fertilized Chirostoma eggs from Lake Chapala into Amistad and other Mexican reservoirs (Clark Hubbs, personal communication to W. Courtenay, 1975). Lake Chapala is inhabited by several Chirostoma species. Consequently, Chirostoma eggs taken from the lake and used for stocking may have been from any one, or a number of species (W. Courtenay, personal communication; Courtenay and Hensley 1979a). The statement by Howells (1991b) that the C. jordani record was "probably based on collections by C. Hubbs" is false. There are no known voucher specimens from Lake Amistad and no known collections of Chirostoma in Texas waters (D. Henderson, personal communication; Clark Hubbs to D. Henderson, personal communication). The Mexican stocking has been the basis for inclusion of Chirostoma jordani in published lists of non-established foreign species of the United States (e.g., Courtenay et al. 1984, 1986).

References: (click for full references)

Barbour, C. D. 1973. The systematics and evolution of the genus Chirostoma Swainson (Pisces, Atherinidae). Tulane Studies in Zoology and Botany 18(3):97-141.

Courtenay, W., Jr. - Florida Atlantic University, Boca Raton, FL. Personal communication.

Contreras, S., and M. A. Escalante. 1984. Distribution and known impacts of exotic fishes in Mexico. Pages 102-130 in W. R. Courtenay, Jr. and J. R. Satuffer, editors. Distribution, biology, and management of exotic fishes. Johns Hopkins University Press, Baltimore, MD.

Courtenay, W. R., Jr., and D. A. Hensley. 1979a. Survey of introduced non-native fishes. Phase I Report. Introduced exotic fishes in North America: status 1979. Report Submitted to National Fishery Research Laboratory, U.S. Fish and Wildlife Service, Gainesville, FL.

Courtenay, W. R., Jr., D. A. Hensley, J. N. Taylor, and J. A. McCann. 1984. Distribution of exotic fishes in the continental United States. Pages 41-77 in W. R. Courtenay, Jr., and J. R. Stauffer, Jr., editors. Distribution, biology and management of exotic fishes. Johns Hopkins University Press, Baltimore, MD.

Courtenay, W. R., Jr., D. A. Hensley, J. N. Taylor, and J. A. McCann. 1986. Distribution of exotic fishes in North America. Pages 675-698 in C. H. Hocutt, and E. O. Wiley, editors. The zoogeography of North American freshwater fishes. John Wiley and Sons, New York, NY.

Howells, R. G. 1992a. Annotated list of introduced non-native fishes, mollusks, crustaceans and aquatic plants in Texas waters. Texas Parks and Wildlife Department, Management Data Series 78, Austin, TX. 19 pp.

Howells, R. G. 1991b. Electrophoretic identification of feral and domestic tilapia in Texas. Texas Parks and Wildlife Department, Management Data Series 62, Austin, TX. 11 pp.

Hubbs, C. - University of Texas, Austin, TX. Personal communication.

Robins, C. R., R. M. Bailey, C. E. Bond, J. R. Brooker, E. A. Lachner, R. N. Lea, and W. B. Scott. 1991b. World fishes important to North Americans exclusive of species from the continental waters of the United States and Canada. American Fisheries Society Special Publication 21. American Fisheries Society, Bethesda, MD. 243 pp.

Other Resources:
US Fish and Wildlife Service Ecological Risk Screening Summary for Chirostoma jordani

Author: Nico, L.

Peer Review Date: 3/5/2011

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.