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.

Eriocheir sinensis
Eriocheir sinensis
(Chinese mitten crab)

Copyright Info
Eriocheir sinensis

Common name: Chinese mitten crab

Taxonomy: available through www.itis.govITIS logo

Injurious: This species is listed by the U.S. Fish and Wildlife Service as injurious wildlife.


Adult Characteristics:
                + hairy claws with white tips, normally equal in size
                + notch between the eyes
                + four lateral carapace spines (fourth spine is small)
                + smooth, round carapace or body shape
                + maximum carapace width (distance across the back) is approximately 80 mm (3 inches)
                + legs over twice as long as the carapace width
                + light brown color

Juvenile Mitten Crab Characteristics:
                + notch between the eyes
                + claws may not be hairy if carapace width is less than 20 mm (¾ inch)
                + claws are hairy by 25 mm (1 inch) carapace width
                + four lateral carapace spines (fourth spine is small)
                + smooth, round carapace or body shape
                + legs over twice as long as the carapace width
                + light brown color 


Size: 3 inch carapace width

Native Range: Pacific coast of China and Korea.

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 Eriocheir sinensis are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
AK200420041Prince of Wales
CA1991200510Honcut Headwaters-Lower Feather; Lower Sacramento; Rock Creek-French Camp Slough; Sacramento-Stone Corral; San Francisco Bay; San Joaquin Delta; San Pablo Bay; Suisun Bay; Upper Deer-Upper White; Upper Merced
CT201220213Housatonic; Long Island Sound; Saugatuck
DE200720102Brandywine-Christina; Broadkill-Smyrna
LA198720222Eastern Louisiana Coastal; Lower Mississippi-New Orleans
MD200520074Chester-Sassafras; Gunpowder-Patapsco; Severn; Upper Chesapeake Bay
NJ200820103Lower Hudson; Mullica-Toms; Sandy Hook-Staten Island
NY200720245Hudson-Wappinger; Lower Hudson; Middle Hudson; Northern Long Island; Sandy Hook-Staten Island
OH197520071Lake Erie
WA199720022Lower Columbia; Lower Columbia-Clatskanie

Table last updated 7/17/2024

† Populations may not be currently present.

Means of Introduction: Ballast water on the West Coast and in the Great Lakes. Its presence in Maryland may either be due to releasing crabs purchased as food (only males are sold), or they may be been introduced by ballast water.

Status: They are established on the California coast, but adults are now rare in San Francisco Bay as of 2012. There is no evidence to show they are establised in the Great Lakes. However, with all the recent collections from the mid-Atlantic Region of the east coast of the United States, reproduction may be occurring. Until 2007, all mitten crabs collected were males. Since then several female specimens were collected, each containing eggs and sperm stored in a special organ. This is evidence of mating but not necessarily of an established population.

Impact of Introduction:
Summary of species impacts derived from literature review. Click on an icon to find out more...


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.

Author: Benson, A. J., and P. L. Fuller

Revision Date: 6/29/2023

Citation Information:
Benson, A. J., and P. L. Fuller, 2024, Eriocheir sinensis: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=182, Revision Date: 6/29/2023, 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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