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.

Lernaea cyprinacea
Lernaea cyprinacea
(anchor worm)

Copyright Info
Lernaea cyprinacea Linnaeus, 1758

Common name: anchor worm

Synonyms and Other Names: Lernaea elegans Leigh-Sharpe 1925
Lernaea carassii Tidd 1933
Lernaea ranae Stunkard and Cable 1913
Lernaeocera esocina Hermann 1783

Taxonomy: available through www.itis.govITIS logo

Identification: Long, thin cylindrical shape with two pairs of hook-like appendages at one end.

Size: 6-11 mm (Haley and Winn 1959)

Native Range: Possibly Eurasia (McLaughlin et al. 2005).

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 Lernaea cyprinacea are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
AZ193020052Lower Colorado Region; Lower Little Colorado
CA200520052California Region; Lower Sacramento
GA197719771Middle Chattahoochee-Lake Harding
HI200520051Hawaii Region
OK201020103Illinois; Lake O' The Cherokees; Lower Neosho
OR200520051Pacific Northwest Region
WA200520051Pacific Northwest Region

Table last updated 6/13/2024

† Populations may not be currently present.

* HUCs are not listed for states where the observation(s) cannot be approximated to a HUC (e.g. state centroids or Canadian provinces).

Ecology: Immatures are found on the gills while mature females are found on the outside surface of fishes where they are known to burrow into the tissue (USGS 2012).

Means of Introduction: Likely introduced through the aquarium trade (Tidd 1934).

Status: Unknown

Impact of Introduction: A minimum of 79 different native and exotic host fish species have been documented in North America (USGS 2012) many of which are found in the southeast.

References: (click for full references)

Haley, A. J., and H. E. Winn.  1959.  Observations of a lernaean parasite of freshwater fishes.  Trans. Am. Microsc. Soc. 88:128-129.

McAllister, C.T., C.R. Bursey, and S.D. Martin. 2011. Lernaea cyprinacea (Crustacea: Copepoda: Lernaeidae) anchorworms from two larval aquatic insects (Ephemeroptera: Baetidae, Trichoptera: Hydropsychidae) in northeastern Oklahoma. Proc. Okla. Acad. Sci 91:37-40.

McLaughlin, P. L. and 39 others. 2005. Common and Scientific Names of Aquatic Invertebrates from the United States and Canada: Crustaceans. American Fisheries Society Special Publication 31, Bethesda, Maryland.

Nepszy, S. J. 1988. Parasites of fishes in the Canadian waters of the Great Lakes.  Great Lakes Fish. Comm. Tech. Rep. No. 51. 106 pp.

Tidd, W. M. 1934. Recent infestations of goldfish and carp by the ‘’anchor parasite,’‘ Lernaea carassii.  Trans. Am. Fish. Soc. 64:176-180.

Timmons, T. J., and W. G. Hemstreet. 1980. Prevalence rate of Lernaea cyprinacea L. (Copepoda: Lernaeidae) on young-of-the-year largemouth bass, (Micropterus salmoides (Lacepede), in West Point Reservoir, Alabama-Georgia, U. S. A.  J. Fish Diseases 3:529-530.

USGS. 2012. Free-living and parasitic copepods (including Branchiurans) of the Laurentian Great Lakes: keys and details on individual species. http://www.glsc.usgs.gov/greatlakescopepods/_DialUp/Detail.asp?GROUP=Parasite&SPECIES=Lernaea%20cyprinacea Accessed 5/13/2012

Other Resources:
Tirmizi, H. 2003. "Lernaea cyprinacea" (On-line), Animal Diversity Web. Accessed February 14, 2012 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Lernaea_cyprinacea.html

Steckler, N., and R.P.E. Yanoung. 2012. Lernaea (Anchorworm) Infestations in Fish. University of Florida IFAS Extension, Gainesville, FL.

Author: Benson, A.J.

Revision Date: 4/3/2015

Citation Information:
Benson, A.J., 2024, Lernaea cyprinacea Linnaeus, 1758: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=2875, Revision Date: 4/3/2015, Access Date: 6/14/2024

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 [6/14/2024].

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