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.

Pacifastacus leniusculus
Pacifastacus leniusculus
(signal crayfish)
Native Transplant
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Pacifastacus leniusculus (Dana, 1852)

Common name: signal crayfish

Synonyms and Other Names: “aquatic cockroaches” (Goldfarb 2015)

Taxonomy: available through www.itis.govITIS logo

Native Range:
US auto-generated map Legend USGS Logo
Alaska auto-generated map
Hawaii auto-generated map
Caribbean auto-generated map
Puerto Rico &
Virgin Islands
Guam auto-generated map
Guam Saipan
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 Pacifastacus leniusculus are found here.

StateYear of earliest observationYear of last observationTotal HUCs with observations†HUCs with observations†
Alaska200220151Kodiak-Afognak Islands
California1895201512Central California Coastal; Klamath-Northern California Coastal; Lake Tahoe; Lower Pit; Lower Sacramento; Mad-Redwood; Monterey Bay; Salinas; San Pablo Bay; Shasta; Truckee; Upper Bear
Nevada196219621Middle Carson
Oregon191420002Lower Columbia-Clatskanie; Williamson

Table last updated 7/4/2018

† Populations may not be currently present.

References: (click for full references)

Goldfarb, B. 2015. Invasive crayfish in Oregon devastate native newts. High Country News. http://www.hcn.org/articles/crayfish-doom-crater-lakes-native-newts-invasive. Created on 09/02/2015. Accessed on 01/24/2018.

Revision Date: 1/24/2018

Citation Information:
U.S. Geological Survey, 2018, Pacifastacus leniusculus (Dana, 1852): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=200, Revision Date: 1/24/2018, Access Date: 7/16/2018

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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URL: https://nas.er.usgs.gov
Page Contact Information: Pam Fuller - NAS Program (pfuller@usgs.gov)
Page Last Modified: Tuesday, July 10, 2018


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. [2018]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [7/16/2018].

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