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.

Hesperoleucus symmetricus
Hesperoleucus symmetricus
(California Roach)
Native Transplant

Copyright Info
Hesperoleucus symmetricus (Baird and Girard, 1854)

Common name: California Roach

Synonyms and Other Names: Lavinia symmetricus

Taxonomy: available through www.itis.govITIS logo

Identification: Moyle (1976a); Page and Burr (1991). Placed in the genus Lavinia by some researchers.

Size: 11 cm.

Native Range: Sacramento--San Joaquin and Pajaro-Salinas River drainages, 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 Hesperoleucus symmetricus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
CA1898201013Big-Navarro-Garcia; Crowley Lake; Cuyama; Lake Tahoe; Lower Eel; Middle Fork Eel; Mojave; Santa Barbara Coastal; Santa Clara; Santa Maria; South Fork Eel; Upper Eel; Ventura
OR194019792Silvies; Warner Lakes

Table last updated 6/24/2024

† Populations may not be currently present.

Means of Introduction: Populations in the Cuyama River, California are presumably the result of bait-bucket introduction (Moyle 1976a). Unknown in Oregon.

Status: Established in at least one river system in California outside its native range (Moyle 1976a). Reported from Oregon (Sigler and Sigler 1987).

Impact of Introduction: Power (1992) demonstrated that introduced roach in the Eel River, California, had cascading effects on the abundance of benthic invertebrates and algae (Parker et al., 1999).

Remarks: Sigler and Sigler (1987), apparently citing Moyle (1976a), stated that California Roach may have been introduced into the Cuyama River of California, although earlier natural stream capture cannot be ruled out. We found no mention of possible stream capture in that earlier reference. The California Roach can survive where most other fishes cannot because of their small size and tolerance of low oxygen levels and high temperatures. Nevertheless, it has declined or disappeared from parts of its native range (the upper San Joaquin, Fresno, and Chowchilla river systems in central California) as a result of a combination of factors, one being predation by the introduced green sunfish Lepomis cyanellus (Moyle 1976b).

References: (click for full references)

Parker, I.M., D. Simberloff, W.M. Lonsdale, K. Goodell, M. Wonham, P.M. Kareiva, M.H. Williamson, B. Von Holle, P.B. Moyle, J.E. Byers, and L. Goldwasser. 1999. Impact: toward a framwork for understanding the ecological effects of invaders. Biological Invasions 1:3-19.

Power, M.E. 1992. Habitat heterogeneity and the functional significance of fish in river food webs. Ecology 73: 1675–1688.

Other Resources:
FishBase Summary

Author: Leo Nico, and Pam Fuller

Revision Date: 12/27/2012

Peer Review Date: 12/27/2012

Citation Information:
Leo Nico, and Pam Fuller, 2024, Hesperoleucus symmetricus (Baird and Girard, 1854): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=543, Revision Date: 12/27/2012, Peer Review Date: 12/27/2012, Access Date: 6/24/2024

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.


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Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [6/24/2024].

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