Astyanax mexicanus
Astyanax mexicanus
(Mexican Tetra)
Native Transplant
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Astyanax mexicanus (De Filippi, 1853)

Common name: Mexican Tetra

Taxonomy: available through www.itis.govITIS logo

Identification: Although previously considered a subspecies of Astyanax fasciatus (Lee et al. 1980 et seq.), A. mexicanus more likely represents a species complex (Mayden et al. 1992). Sublette et al. (1990) and Page and Burr (1991) gave distinguishing characteristics. The species was included in a state key by Miller (1952). Illustrations and photographs were provided by Miller (1952), Miller and Robison (1973), Minckley (1973), Sublette et al. (1990), and Page and Burr (1991).

Size: 12 cm.

Native Range: Subtropical America. Mostly eastern and central Mexico and also the lower Rio Grande, lower Pecos, and Nueces rivers in Texas (Lee et al. 1980 et seq.; Page and Burr 1991). Historically, found in the Pecos River drainage and lower Rio Grande in New Mexico, but now restricted to the Pecos drainage downstream of Dexter (Sublette et al. 1990).
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Interactive maps: Point Distribution Maps

Nonindigenous Occurrences: The species was first mentioned as a baitfish in the lower Colorado River at Yuma, Arizona, in the early 1950s, but no specimens had been collected up to that time from open waters (Evans and Douglas 1950; Miller 1952). It was first recorded in open waters, when several juvenile to subadult specimens were taken from the Colorado River just below Morelos Dam in 1966 (Minckley 1973). There were several reports from the lower Colorado River in California in 1950 (Minckley 1973; Swift et al. 1993). According to Hubbs et al. (1979), the fish was introduced but never became established in the state. There were two records of fish taken from lakes in the Red River drainage, northwestern part of Louisiana. The first was based on a single specimen taken from Lake Bistineau Reservoir in October 1954 (Lambou 1962). The species was also recorded from Cross Lake, near Shreveport (Lee et al. 1980 et seq.). The species has been recorded from the Rio Grande drainage in southern New Mexico (Lee et al. 1980 et seq.; Page and Burr 1991). A single fish was taken from Big Darby Creek, Union County, Ohio, on 22 October 1966 (Trautman 1981). A single fish was taken in 1953 from Lake Texoma, Oklahoma, a reservoir of the Red River bordering Texas (Riggs 1954); large numbers of additional specimens were taken from the same reservoir in 1955, suggesting that the species was reproducing (Dowell and Riggs 1958). Miller and Robison (1973) repeated that a breeding population may be established in Lake Texoma. The species was reported as having been introduced, but probably not established in several other lakes including Lake Spavinaw in the Neosho drainage in the northeastern part of state; Lake Murray in Love and Carter counties; Lake Tenkiller in Cherokee and Sequoya counties; Ft. Gibson Lake; and perhaps elsewhere (Miller and Robison 1973; Lee et al. 1980 et seq.). The species has been reported at many sites, especially springs, in central and northeastern parts of Texas (Hubbs et al. 1978; Lee et al. 1980 et seq.; Hubbs et al. 1991). Specifically, introduced populations have been found in various parts of the Edwards Plateau and in the Red River and San Antonio drainage above Denton (Lee et al. 1980 et seq.), and reported in drainages from San Antonio Bay to Galveston Bay (Conner and Suttkus 1986). Recently, this species was recorded for the Sabine Lake watershed in the southeastern part of the state (Bechler and Harrel 1994).

Means of Introduction: All or most introductions have probably resulted from bait bucket releases (e.g., Miller and Robison 1973). The first A. mexicanus observed outside their native range were seen in a bait shop in Yuma, Arizona, along the Colorado River in 1950; presumably, these fish were a species contaminant that arrived in a minnow shipment (Evans and Douglas 1950; Miller 1952).

Status: Established in Texas (outside native range). Formerly found in the Rio Grande valley in New Mexico, but now possibly extirpated (although these likely represented native records and not introductions). Previously established in southern Oklahoma; the species has not been taken in recent years and is now considered extirpated (Cashner and Matthews 1988). Reported from Arizona, California, and Louisiana.

Impact of Introduction: Unknown.

Remarks: This is the only characid species native to the United States. Because it is predacious and highly aggressive, there is concern that this species could impact native fishes by preying on their young (Miller 1952; Minckley 1973). Lee et al. (1980 et seq.) and Page and Burr (1991) provided distribution maps; these authors considered Mexican tetra populations recorded from the Rio Grande drainage in southern New Mexico, and in the associated nearby border area of Texas, to be introduced. In contrast, Sublette et al. (1990) believed that this area constituted part of the species' natural or historical distribution. It now appears to be extirpated from the Rio Grande in New Mexico and is on the decline in many portions of the Pecos River drainage; as such, the species is classified as "state endangered" by New Mexico (Sublette et al. 1990).

Voucher specimens: Ohio (OSM 14147); Texas (INHS 75684).

References: (click for full references)

Bechler, D. L., and R. C. Harrel. 1994. Notes on the biology and occurrence of Astyanax mexicanus (Characidae, Teleostei) in southeast Texas. Texas Journal of Science 46(3):293-294.

Cashner, R. C., and W. J. Matthew. 1988. Changes in the known Oklahoma fish fauna from 1973 to 1988. Proceedings of the Oklahoma Academy of Science 68:1-7.

Conner, J. V., and R. D. Suttkus. 1986. Zoogeography of freshwater fishes of the western Gulf Slope of North America. Pages 413-456 in C. H. Hocutt and E. O. Wiley, editors. The zoogeography of North American freshwater fishes. John Wiley and Sons, New York, NY.

Dowell, V. E., and C. D. Riggs. 1958. Further observation on Astyanax fasciatus and Menidia audens in Lake Texoma. Proceedings of the Oklahoma Academy of Science 33(1955):52-53.

Evans, W. A., and P. A. Douglas. 1950. Notes on fishes recently introduced into southern California. California Fish and Game 36:435-436.

Hubbs, C., T. Lucier, G. P. Garrett, R. J. Edwards, S. M. Dean, E. Marsh, and D. Belk. 1978. Survival and abundance of introduced fishes near San Antonio, Texas. Texas Journal of Science 30(4):369-376.

Hubbs, C. L., W. I. Follett, and L. J. Dempster. 1979. List of the fishes of California. California Academy Science Occasional Papers 133. 51 pp.

Koster, W. J. 1957. Guide to the fishes of New Mexico. University of New Mexico Press, Albuquerque, NM.

Lambou, V. W. 1962. Fishes occurring in Lake Bistineau, Louisiana. Proceedings of the Louisiana Academy of Sciences 25:75-79.

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

Mayden, R. L., editor. 1992. Systematics, historical ecology, and North American freshwater fishes. Stanford University Press, Stanford, CA.

Miller, R. J., and H. W. Robison. 1973. The fishes of Oklahoma. Oklahoma State University Press, Stillwater, OK.

Miller, R. R. 1952. Bait fishes of the lower Colorado River, from Lake Mead, Nevada, to Yuma, Arizona, with a key for identification. California Fish and Game 38(1):7-42.

Minckley, W. L. 1973. Fishes of Arizona. Arizona Fish and Game Department. Sims Printing Company, Inc., Phoenix, 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.

Riggs, C. D. 1954. The occurrence of Astyanax fasciatus mexicanus in Lake Texoma, Oklahoma. Proceedings of the Oklahoma Academy of Science 33(1952):141.

Sublette, J. E., M. D. Hatch, and M. Sublette. 1990. The fishes of New Mexico. New Mexico Department of Game and Fish, University of New Mexico Press, Albuquerque, NM. 393 pp.

Swift, C. C., T. R. Haglund, M. Ruiz, and R. N. Fisher. 1993. The status and distribution of the freshwater fishes of southern California. Bulletin of the Southern California Academy of Science 92(3):101-167.

Trautman, M. B. 1981. The fishes of Ohio. Ohio State University Press, Columbus, OH.

Other Resources:
FishBase Summary

Author: Nico, L.

Revision Date: 7/27/2004

Peer Review Date: 4/1/2016

Citation Information:
Nico, L., 2018, Astyanax mexicanus (De Filippi, 1853): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL,, Revision Date: 7/27/2004, Peer Review Date: 4/1/2016, Access Date: 3/20/2018

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.

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Citation information: U.S. Geological Survey. [2018]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [3/20/2018].

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