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.

Platygobio gracilis
Platygobio gracilis
(Flathead Chub)
Native Transplant

Copyright Info
Platygobio gracilis (Richardson, 1836)

Common name: Flathead Chub

Taxonomy: available through www.itis.govITIS logo

Identification: Woodling (1985); Hubbs et al. (1991); Page and Burr (1991); Etnier and Starnes (1993); commonly used name is Hybopsis gracilis.

Size: 32 cm.

Native Range: Mackenzie, Saskatchewan, and Lake Winnipeg drainages in Yukon, Northwest Territories, Manitoba, Saskatchewan, Alberta, and British Columbia; Missouri-Mississippi River basin from southern Alberta and Montana to Louisiana; upper Rio Grande (including Pecos) drainage, New Mexico. Restricted to Mississippi River proper in Missouri, Illinois, and south; localized in Arkansas River drainage in Oklahoma, Texas, and New Mexico (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 Platygobio gracilis are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
CO198619861San Luis
MT199919992Lower Yellowstone-Sunday; Middle Kootenai
NE200720071Upper Little Blue
NM195719571Upper Gila-Mangas
WY201020101Central Bear

Table last updated 7/17/2024

† Populations may not be currently present.

Means of Introduction: Introduced in the Gila River drainage of New Mexico via bait-bucket release (Koster 1957; Sublette et al. 1990). This species was privately stocked as prey for a trout hatchery in the Russell Lakes area of Colorado; the fish came from the Arkansas River drainage (Zuckerman and Behnke 1986). Probably bait-bucket release in Minnesota.

Status: Recorded as having been established, at least temporarily, in part of the Gila drainage of New Mexico (Koster 1957); in contrast, Sublette et al. (1990) reported that the species did not became established there. In Colorado, the species apparently persisted for 15 years in the San Luis Closed Basin, but it is no longer considered extant in that region (Zuckerman and Behnke 1986). Recorded as occurring in Minnesota.

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: The only New Mexico site where this species was mentioned as being introduced is Taylor Creek (Sublette et al. 1990). Koster (1957) did not mention the specific locality where this species occurred within the Gila River drainage of New Mexico. The Flathead Chub is used as a bait fish in selected areas of the country (Koster 1957; Scott and Crossman 1973). Crossman and McAllister (1986) listed this species as possibly present in the U.S. section of the Red River drainage but gave no indication it was introduced there. Lee et al. (1980 et seq.) did not depict the species in that region.

References: (click for full references)

Peterka, J. J. and T. M. Koel. 1996. Distribution and Dispersal of Fishes in the Red River Basin. Report submitted to Interbasin Biota Transfer Studies Program, Water Resources Research Research Institute, Fargo, ND. Northern Prairie Wildlife Research Center Home Page.  http://www.npwrc.org/resource/distr/others/fishred/fishred.htm (version 29AUG97).

Other Resources:
FishBase Summary

Author: Nico, L.

Revision Date: 12/2/2019

Peer Review Date: 3/18/2010

Citation Information:
Nico, L., 2024, Platygobio gracilis (Richardson, 1836): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=625, Revision Date: 12/2/2019, Peer Review Date: 3/18/2010, Access Date: 7/17/2024

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 [7/17/2024].

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