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.

Esox americanus vermiculatus
Esox americanus vermiculatus
(Grass Pickerel)
Native Transplant

Copyright Info
Esox americanus vermiculatus Lesueur, 1846

Common name: Grass Pickerel

Taxonomy: available through www.itis.govITIS logo

Native Range: Florida and Gulf Slope drainages west to the Brazos River, Texas; northward in the Mississippi drainage (eastern Texas and Oklahoma, southern and eastern Missouri, the eastern board of Iowa, and southeastern Wisconsin) to the Great Lakes (southern Michigan, north shore of lakes Erie and Ontario) (Crossman 1978). Remnant populatoins in Nebraska likely refect a once, much larger westward range (Crossman 1978). Individuals in the southeastern part of the range are intergrades with E. a. americanus (Crossman 1978; Lee et al. 1980).

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 Esox americanus vermiculatus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
CA189619783California Region; San Diego; Upper Cache
CO197419781Upper South Platte
OR199419941Pacific Northwest Region
WA189020039Franklin D. Roosevelt Lake; Hangman; Little Spokane; Lower Snake; Lower Snake-Tucannon; Palouse; Rock; Upper Crab; Upper Spokane
WI194520103Castle Rock; Chippewa; Upper Wisconsin

Table last updated 6/22/2024

† Populations may not be currently present.

Means of Introduction: This species was stocked intentionally and possibly accidentally; it was stocked illegally in Oregon.  Probably introduced inot Washington as misidentified northern pike E. lucius (Chapman 1942); it is also possible that grass pickerel were introduced into Idaho along with northern pike, and that the former species reached Washington by "some devious means" (Wydoski and Whitney 1979).  Introduced into northern Wisconsin in the 1940s (Crossman 1978).

Status: Extirpated in California; established in Colorado, Washington, and Wisconsin; unknown in Oregon.

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: This species is sometimes mistaken for the young of other Esox species. 

Other Resources:
FishBase Summary

Author: Fuller, P.

Revision Date: 3/4/2015

Peer Review Date: 3/4/2015

Citation Information:
Fuller, P., 2024, Esox americanus vermiculatus Lesueur, 1846: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=675, Revision Date: 3/4/2015, Peer Review Date: 3/4/2015, Access Date: 6/22/2024

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 [6/22/2024].

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.