endemic to a single nation
Regularity: Regularly occurring
Type of Residency: Year-round
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Ranges along the Atlantic watersheds from Maine to Virginia. Although introduced to New Brunswick and parts of Quebec, some occurrences in Quebec are likely the result of an extension of its natural range along the Champlain and Memphremagog Lakes (Dube and Desroches, 2007). It as been introduced into western Europe (Hobbs 1989). Although first introduced into Europe in 1890 (Germany), secondary introductions have occurred throughout continental Europe in over 20 countries (not yet in the Iberian Peninsula) making it one of the most common crayfish there (Petrusek et al., 2006; Parvulescu et al., 2009; Holdich and Black, 2007; Baitchorov and Giginiak, 2009; Puky, 2009).
The Extent of Occurrence (EOO) of this species has been estimated to exceed 2 million km2.
Habitat Type: Freshwater
Comments: Prefers shallow bay areas of larger lakes (Hogger, 1988). It also inhabits clear streams that are 10100 m wide, with silt, cobble, gravel and sand substrates (Jezerinac 1995; Aiken 1965). This species has also been found in lakes (Aiken 1965). Individuals are often found in shallow depressions in pools and have rarely been captured where silt is absent from the substrate (Jezerinac 1995).
Habitat and Ecology
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: > 300
Comments: In New Jersey, Francois (1959) cites it for Bergen, Burlington, Camden, Gloucester, hunterdon, Mercer, Monmouth, Morris, Passaic, Sussex, Sommerset, and Warren Cos.; as well as Philadelphia and Bucks Cos., Pennsylvania. Horowitz and Flinders (2004) found it to be uncommon (2 of 15 stations) in the Piedmont, Ridge and Valley and Highlands regions of New Jersey. It was recently documented in the vicinity of Plummers Island (bank of Potomac River), Montgomery Co., Maryland (Norden, 2008). In Maryland, it was historically the most abundant species but is currently present, but uncommon, in the Appalachian Plateau in tributaries to the North Branch Potomac River (possibly via dispersal through the low-gradient Chesapeake and Ohio Canal) and so is now uncommon west of the Piedmont, somewhat common but declining within the Piedmont (except where non-native crayfish species are absent), and common in the Coastal Plain (Killian et al., 2010). In New York's Hudson River drainage, Smith (1979) added Rennselaer Co. In southern New England, Smith (1981) documented it in the Pawcatuck (CT/RI), Thames (CT), Connecticut (MA/CT), and Housatonic (CT) River systems. Although there is question as to whether New England occurrences are native, Faxon (1914) cites occurrences in Massachusetts. Smith (2000) notes that in southern New England, native populations (if, indeed native) are confined to major south flowing river systems including the Housatonic River, Connecticut River (where it is common), and Thames River drainages; with less frequently encountered populations east of these drainages (probably introduced) and scattered populations known from the Merrimack River, Charles River, Narragansett Bay, Mount Hope Bay, and other coastal drainages (not the Hudson River drainage). Although introduced to New Brunswick and parts of Quebec, some occurrences in Quebec are likely the result of an extension of its natural range along the Champlain and Memphremagog Lakes (Dube and Desroches, 2007).
Comments: This species is known to be abundant in sites of suitable habitat.
Molecular Biology and Genetics
Statistics of barcoding coverage: Orconectes limosus
Public Records: 5
Specimens with Barcodes: 8
Species With Barcodes: 1
Barcode data: Orconectes limosus
There are 4 barcode sequences available from BOLD and GenBank. Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species. See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
National NatureServe Conservation Status
Rounded National Status Rank: N4 - Apparently Secure
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: This species is widespread and common along North American Atlantic drainages but has been introduced widely to the rest of North America and across western Europe.
Intrinsic Vulnerability: Not intrinsically vulnerable
Environmental Specificity: Broad. Generalist or community with all key requirements common.
IUCN Red List Assessment
Red List Category
Red List Criteria
Global Short Term Trend: Increase of 10 to >25%
Comments: Although first introduced into Europe in 1890 (Germany), secondary introductions have occurred throughout continental Europe in over 20 countries (not yet in the Iberian Peninsula) making it one of the most common crayfish there (Parvulescu et al., 2009; Holdich and Black, 2007; Baitchorov and Giginiak, 2009; Puky, 2009). It is declining in Maryland within and west of the Piedmont at the expense of increased range expansion of Orconectes virilis (Kilian et al., 2010) and similar trends have been observed in southeastern Pennsylvania (Bouchard et al., 2007) and West Virginia (Jezerinac et al., 1995) where it is now believed extirpated (Swecker et al., 2010).
Global Long Term Trend: Increase of >25%
Degree of Threat: Low
Comments: There are no known major threats to this species. Hybridization is known to have occurred between Orconectes limosus and Orconectes rusticus at a single locality in Massachusetts. The cause of this hybridization are not known, however, transplanting of species to new habitats or the inability to find conspecific mates due to habitat alteration are both possible (Smith, 1981). It is declining in Maryland within and west of the Piedmont at the expense of increased range expansion of Orconectes virilis (Kilian et al., 2010) and similar trends have been observed in southeastern Pennsylvania (Bouchard et al., 2007) and West Virginia (Jezerinac et al., 1995) where it is now believed extirpated (Swecker et al., 2010). However, this is not having a major impact on the global population of this species.
It is likely that this species is experiencing localized declines due to urbanization, alterations to the hydrological regime and water pollution (S. Adams, G. Schuster, C. Taylor, pers. comm. 2009), but these are very unlikely to be threatening the species.
Global Protection: Unknown whether any occurrences are appropriately protected and managed
This species is a carrier of the crayfish plague and poses a great threat to native crayfish species in Europe (Holdich and Black 2007).
Further research is required on the population abundance of this species and its life history.
Orconectes limosus, Eastern Crayfish, Or Delcore Crayfish is a species of crayfish in the family Cambaridae. It is native to the east coast of North America, from Maine to the lower James River, Virginia, but has also been introduced to Europe. It is unusual in that it lives in silty streams, rather than the clear water usually preferred by crayfish. Like Pacifastacus leniusculus, another invasive North American crayfish, O. limosus carries crayfish plague and is a threat to native crayfish. 
O. limosus was introduced to Germany in 1890, and has since spread across much of Northern Europe, recently reaching the United Kingdom. It has also spread southwards as far as the Danube in Serbia.
Orconectes limosus can reproduce sexually or by parthenogenesis. Lobsters and Crayfish are decapods meaning that they have 10 legs. 2 of them are claws. These Crayfish live on the bottom of the freshwater pools, such as lakes, ponds and swamps. They prefer flat, sandy, and rocky floors. They are also found outside the water on beaches or lawns near the pool of water. They use rocks to make burrows while in the water. This is a very common species of cray, especially on Northeast United States, and Southeast Canada.
- S. Adams, G. A. Schuster & C. A. Taylor (2010). "Orconectes limosus". IUCN Red List of Threatened Species. Version 3.1. International Union for Conservation of Nature. Retrieved October 8, 2010.
- James W. Fetzner, Jr. (December 6, 2006). "Orconectes (Faxonius) limosus (Rafinesque, 1817)". Crayfish Taxon Browser. Carnegie Museum of Natural History.
- Whitney Stocker. "Orconectes (Faxonus) limosus (Rafinesque, 1817)". Retrieved August 29, 2007.
- David Holdich & John Black (2007). "The spiny-cheek crayfish, Orconectes limosus (Rafinesque, 1817) (Crustacea: Decapoda: Cambaridae), digs into the UK". Aquatic Invasions 2 (1): 1–16. doi:10.3391/ai.2007.2.1.1.
- S. Pavlović, S. Milošević, S. Borković, V. Simić, M. Paunović, R. Žikić & Z. Saičić (2006). "A report of Orconectes (Faxonius) limosus (Rafinesque, 1817) (Crustacea: Deacpoda: Astacidea: Cambaridae: Orconectes: subgenus Faxonius) in the Serbian part of the River Danube". Biotechnology & Biotechnological Equipment 20 (1): 53–56.
- M Buřič, M Hulák, A Kouba, A Petrusek, P Kozák (2011). "successful crayfish invader is capable of facultative parthenogenesis: a novel reproductive mode in decapod crustaceans". PLoS ONE 6 (5): e20281. doi:10.1371/journal.pone.0020281. PMC 3105005. PMID 21655282.
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