Orconectes rusticus


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Orconectes rusticus
Species Authority: (Girard, 1852)
Common Name(s):
English Rusty Crayfish

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2010
Date Assessed: 2010-06-01
Assessor(s): Adams, S., Schuster, G.A. & Taylor, C.A.
Reviewer(s): Collen, B. & Richman, N.
Contributor(s): Livingston, F., Livingston, F., Soulsby, A.-M., Batchelor, A., Dyer, E., Whitton, F., Milligan, H.T., Smith, J., Lutz, M.L., De Silva, R., McGuinness, S., Kasthala, G., Jopling, B., Sullivan, K. & Cryer, G.
Orconectes rusticus has been assessed as Least Concern (LC). This species of crayfish is highly invasive, a habitat generalist and consistently outcompetes other species of Orconectes outside its native range. At present, there are no known threats to this species.

Geographic Range [top]

Range Description: This species is native to the Ohio river system, which spreads through the states of: Ohio, Kentucky, Michigan, and Indiana(Taylor et al. 2005).  It has an introduced range which includes: Ontario, Illinois, Tennessee, Missouri, West Virginia, Iowa, Minnesota, New York, New Jersey, Pennsylvania, Wisconsin, Vermont, Massachusetts, Connecticut, Maine, New Hampshire and New Mexico (Taylor et al. 2005).

Thus, the Extent of Occurrence (EOO) of this species has been estimated to exceed 604,000 km2

Canada (Ontario - Introduced); United States (Connecticut - Introduced, Illinois - Introduced, Indiana, Iowa, Kentucky, Maine - Introduced, Massachusetts - Introduced, Michigan, Minnesota - Introduced, New Hampshire - Introduced, New Jersey - Introduced, New Mexico - Introduced, New York, Ohio, Pennsylvania, Tennessee - Introduced, Vermont - Introduced, West Virginia - Present - Origin Uncertain, Wisconsin)
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: This is a common species and has become the dominant crayfish in much of its range in recent years (Kulhmann 2008).
Population Trend: Stable

Habitat and Ecology [top]

Habitat and Ecology: This is a generalist species that inhabits permanent streams and lakes with a range of substrates such as clay, silt, sand and gravel (Thoma and Jezerinac 2000, Taylor et al. 2005). It prefers areas which consists of rocks, logs or other debris which they use to construct shallow excavations underneath (Taylor et al. 2005). It has been shown to breed very early in spring (March - April) before most other crayfish species (Taylor et al. 2005). Juveniles feed heavily on benthic invertebrates and, in some parts of its range, it has been estimated that this species can consume twice as much food as the native and similarly-sized Virile Crayfish (Orconectes virilis) because of a higher metabolic rate. This severely increases competition between the two species (Taylor et al. 2005). In addition, this species is tolerant to pollution such as septic tank discharge and organic pollution (Jezerinac et al. 1995).

This species has a high rate of reproduction (Taylor et al. 2005). In Ontario alone it has displaced the local species in numerous waterways throughout the region (Taylor et al. 2005). 
Not only is it a larger species, but its breeding patterns also account for its  for its dominance due to:earlier breeding season, higher fecundity, and faster larval and juvenile development (Taylor et al. 2005).
Systems: Freshwater

Threats [top]

Major Threat(s): There are no major threats to this species currently known.

Conservation Actions [top]

Conservation Actions: This species has been given the heritage rank of G5 by NatureServe (Taylor et al. 2007, NatureServe 2009) and Currently Stable by the American Fisheries Society (Taylor et al. 2007). 

Citation: Adams, S., Schuster, G.A. & Taylor, C.A. 2010. Orconectes rusticus. The IUCN Red List of Threatened Species. Version 2015.2. <>. Downloaded on 02 September 2015.
Disclaimer: To make use of this information, please check the <Terms of Use>.
Feedback: If you see any errors or have any questions or suggestions on what is shown on this page, please provide us with feedback so that we can correct or extend the information provided