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.

Hysterocarpus traskii
Hysterocarpus traskii
(Tule Perch)
Native Transplant

Copyright Info
Hysterocarpus traskii Gibbons, 1854

Common name: Tule Perch

Taxonomy: available through www.itis.govITIS logo

Identification: Moyle (1976a); McGinnis (1984); Page and Burr (1991). Original spelling ends with ii (Nelson et al. 2004).

Size: 15 cm.

Native Range: Formerly in low-elevation waters of the Sacramento-San Joaquin River drainage, as well as Clear Lake, Coyote Creek, and the Russian, Napa, Pajaro, and Salinas rivers. Now apparently extirpated from the Pajaro, Salinas, and San Joaquin rivers (Moyle 1976a). Lee et al. (1980 et seq.) provided a dot distribution map for the species.

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: The Tule Perch was introduced in the early 1970s into O'Neill Forebay of San Luis Reservoir, and Los Banos Reservoir in Merced County, California (Moyle 1976a). McGinnis (1984) reported that it also has been introduced into a number of small lakes and ponds, such as Lake Merced in San Francisco, where the species is doing well.

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 Hysterocarpus traskii are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
CA197619761Middle San Joaquin-Lower Chowchilla

Table last updated 5/28/2024

† Populations may not be currently present.

Means of Introduction: Presumably gained access to these areas via the California Aqueduct.

Status: Established in parts of California outside its native range (Moyle 1976a).

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: Moyle (1976a) noted that introductions involved what is considered by some to be a subspecies (i.e., H. t. Triassic).

References: (click for full references)

Nelson, J. S., E. J. Crossman, H. Espinosa-Perez, L. T. Findley, C. R. Gilbert, R. N. Lea and J. D. Williams. 2004. Common and Scientific Names of Fishes from the United States, Canada and Mexico, Sixth Edition. American Fisheries Society Special Publication 29. Bethesda, MD.

Other Resources:
FishBase Summary

Author: Pam Fuller, and Leo Nico

Revision Date: 4/30/2018

Peer Review Date: 10/8/2008

Citation Information:
Pam Fuller, and Leo Nico, 2024, Hysterocarpus traskii Gibbons, 1854: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=668, Revision Date: 4/30/2018, Peer Review Date: 10/8/2008, Access Date: 5/28/2024

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 [5/28/2024].

Contact us if you are using data from this site for a publication to make sure the data are being used appropriately and for potential co-authorship if warranted.

For general information and questions about the database, contact Wesley Daniel. For problems and technical issues, contact Matthew Neilson.