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.

Gila orcuttii
Gila orcuttii
(Arroyo Chub)
Native Transplant

Copyright Info
Gila orcuttii (Eigenmann and Eigenmann, 1890)

Common name: Arroyo Chub

Taxonomy: available through www.itis.govITIS logo

Identification: Moyle (1976a); Page and Burr (1991).

Size: 40 cm.

Native Range: Malibu Creek, Santa Clara, San Luis Rey, and Santa Margarita River drainages, southern California (Page and Burr 1991).

Native range data for this species provided in part by NatureServe NS logo
Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Gila orcuttii are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
CA193020119Cuyama; Mojave; San Felipe Creek; San Francisco Bay; Santa Ana; Santa Barbara Coastal; Santa Clara; Santa Maria; Santa Ynez

Table last updated 4/12/2024

† Populations may not be currently present.

Means of Introduction: Bait bucket release, stock contamination with trout and mosquitofish in the 1930s and 1940s (Swift et al. 1993). Although originally thought to be native to the Mohave River, it was later discovered that the species' presence was the result of bait introductions about 1930 by trout anglers (Miller et al. 1991). The stocking of San Felipe Creek was part of a series of experiments to test the effects of changed environment on meristic and morphometric characters (Miller 1968).

Status: Established in parts of California outside its native range. The San Felipe population did not survive (Miller 1968).

Impact of Introduction: Introduced G. orcuttii hybridized with endangered Mohave tui chub G. bicolor mohavensis; since its introduction in the 1930s the continued mass hybridization is believed to have replaced all, or most, pure stock of the tui chub in the Mohave River drainage (Hubbs and Miller 1943; Moyle 1976a, 1976b; Miller et al. 1991; Swift et al. 1993).

Remarks: Species of special concern in California. There is some disagreement in the literature concerning the extent of this species' native distribution. Miller (1968) and Bell (1978) concluded that its occurrence in the Santa Clara River system probably represented an introduction. Lee et al. (1980 et seq.) indicated that G. orcutti was possibly introduced into Malibu Creek and that it was widely introduced north to Santa Inez River and Mojave River of Death Valley drainage. In contrast, Moyle (1976a) included the upper Santa Clara River system as part of this species' native distribution. Page and Burr (1991) also included the Santa Clara drainage in its native range. Hubbs and Miller (1943) provided a detailed description of G. bicolor mohavensis x G. orcuttii hybrids. They also found evidence of backcrossing.

References: (click for full references)

Bell, M.A. 1978. Fishes of the Santa Clara system, southern California. Contributions in Science, Natural History Museum of Los Angeles County 295:1-20.

Hubbs, C.L., and R.R. Miller. 1943. Mass hybridization between two genera of cyprinid fishes in the Mohave desert, California. Papers of the Michigan Academy of Science, Arts, and Letters 28:343-378.

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. Volume 1980. North Carolina State Museum of Natural History, Raleigh.

Miller, R.R. 1968. Records of some native freshwater fishes transplanted into various waters of California, Baja California, and Nevada. California Fish and Game 54:170-179.

Miller, R.R., C. Hubbs, and F.H. Miller. 1991. Ichthyological exploration of the American West: the Hubbs-Miller era, 1915-1950. Pages 19-40 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.

Moyle, P.B. 1976a. Inland fishes of California. University of California Press Berkeley, CA. http://books.google.com/books?id=8ZCStnV581kC&printsec=frontcover&dq=fishes+of+california&hl=en&sa=X&ei=t0dOT-P-Nsna0QH88rS7Ag&ved=0CDUQ6AEwAA#v=onepage&q=fishes%20of%20california&f=false.

Moyle, P.B. 1976b. Fish introductions in California: History and impact on native fishes. Biological Conservation 9:101-118.

Page, L.M. and B.M. Burr. 1991. A Field Guide to Freshwater Fishes - North America North of Mexico. Volume 42. Houghton Mifflin Company, Boston, MA.

Sigler, W.F., and J.W. Sigler. 1987. Fishes of the Great Basin: a natural history. University of Nevada Press, Reno, NV.

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 Sciences 92(3):101-167.

Tilmant, J. T. 1999. Management of nonindigenous aquatic fish in the U.S. National Park System. Paper presented at the 129th Annual Meeting of The American Fisheries Society, Charlotte, North Carolina, September 1, 1999:50.

Other Resources:
FishBase Summary

Author: Fuller, P.

Revision Date: 8/5/2004

Peer Review Date: 8/5/2004

Citation Information:
Fuller, P., 2024, Gila orcuttii (Eigenmann and Eigenmann, 1890): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=540, Revision Date: 8/5/2004, Peer Review Date: 8/5/2004, Access Date: 4/12/2024

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.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [4/12/2024].

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