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.

Faxonius propinquus
Faxonius propinquus
(Northern clearwater crayfish)
Native Transplant

Copyright Info
Faxonius propinquus (Girard, 1852)

Common name: Northern clearwater crayfish

Synonyms and Other Names: Orconectes propinquus. This species underwent a reclassification in 2017, changing the genus of non-cave dwelling Orconectes to Faxonius (Crandall and De Grave 2017).

Taxonomy: available through www.itis.govITIS logo

Identification: Faxonius propinquus are a relatively small crayfish that are typically brownish-green with a dark saddle spanning the dorsal surface of its abdomen. The tips of their claws (chelae) are orange or red with black subterminal rings (Guarino et al. 2012; Taylor et al. 2015). Descriptions and illustrations of the defining morphological features of F. propinquus are given by Taylor et al. (2015). These features include an excavated rostrum that is nearly straight or slightly concave with margins that terminate to strong spines. A strong median carina is present, and chelae are large with moderately long fingers. Two rows of rounded tubercles are found along mesial margin of palm region. Form 1 (breeding) males have gonopods with two short straight elements that are in line with main shaft and have a nearly straight dorsal edge.

Size: On average, Northern Clearwater Crayfish reach a carapace length (CL) of 25–35 millimeters (mm). Though rare, individuals measuring up to 40 mm CL have been collected (Van Deventer 1937; Momot et al. 1978).

Native Range: Faxonius propinquus is a wide-ranging species (Fitzpatrick 1967), which is native to all the Great Lakes and their drainages, as well as other nearby drainages such as upper Hudson River. It can be found in western Vermont, and its native range extends west to southern Minnesota. The south-western margin of the range includes the Wabash River drainage in Indiana and extends through most of Illinois into north-eastern Iowa (Crocker and Barr 1968; Page 1985; Peters et al. 2014).

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 Faxonius propinquus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
WI198320032Flambeau; Upper Wisconsin

Table last updated 6/19/2024

† Populations may not be currently present.

Ecology: Faxonius propinquus are generalized omnivorous feeders (Van Deventer 1937; Crocker and Barr 1968). Stomach contents of most adult F. propinquus examined by Van Deventer (1932) contained filamentous algae, plant material, and seeds. Additionally, insect fragments from mayfly, stonefly (Plecoptera), cranefly (Tipulidae), midge (Chironomidae) and mosquito larvae (Culicidae) were found (Bovbjerg 1952). Faxonius propinquus will also consume small mollusks, such as Zebra Mussels (Dreissena polymorpha), if they are present (MacIsaac 1994). When exposed to Zebra Mussels, MacIsaac (1994) found that F. propinquus showed a strong preference for consuming small individuals (3-5 mm), but they also preyed upon larger D. polymorpha up to 14 mm.

Faxonius propinquus have been found to occupy rivers, swiftly flowing streams, and lakes throughout its range. Though well-established populations have been observed in lakes (Bovbjerg 1952), F. propinquus show a habitat preference for clear, lotic systems with rocky substrates (Van Deventer 1937; Bovbjerg 1952). They are often collected from under large rocks and other debris in streams where they seek shelter in shallow crevices (Van Deventer 1937; Bovbjerg 1952; Taylor et al. 2015). Faxonius propinquus do not construct burrows (Van Deventer 1937; Bovbjerg 1952; Berrill and Chenoweth 1982). They are confined to permanent water bodies where they occupy benthic environments throughout the year (Van Deventer 1937; Bovbjerg 1952). In an experiment examining their tolerance to desiccation, Bovbjerg (1952) found that no F. propinquus burrowed, even in soft substrates, when water levels subsided. Their inability to burrow led to high rates of mortality due to desiccation. This suggests that F. propinquus’ absence in temporary bodies of water can be attributed to its inability to survive dry periods (Bovbjerg 1952).

Ortmann (1906) classified the genus into two groups based on their life history: the “cool water type” which breeds year-round, and a “warm water type” which has a breeding season that is restricted to the fall and spring. By Ortmann’s description, F. propinquus is considered a “cool water type” crayfish, because it has fall and spring breeding season that is followed by a period where males revert to their second form (the non-reproductive stage) (Ortmann 1906; Van Deventer 1932). The time and length of the F. propinquus mating season varies greatly with latitude. Faxonius propinquus have been observed copulating from July through November, and in the spring as late March (Ortmann 1906; Van Deventer 1937; Crocker 1957; Fielder 1972). Populations in the more northern latitudes tend to mate in the fall, while those that reside further south may mate in both the fall and early spring (Van Deventer 1937; Fielder 1972).

Females lay their eggs during the spring as temperatures increase, and in most populations, egg-bearing females can be found during the months of April and May (Van Deventer 1932; Crocker and Barr 1968; Fielder 1972). The eggs hatch between May and July, and the young remain attached to the mother’s abdomen for about two weeks (Crocker and Barr 1968). At their first appearance, the free-swimming young measure roughly 3.9-6 mm CL (~ 8-12 mm in total length) (Van Deventer 1932; Crocker and Barr 1968; Fielder 1972). Juveniles grow about 1-2 mm CL each molt, and by the end of their first summer they reach sexual maturity at approximately 16-20 mm CL (Van Deventer 1937; Crocker and Barr 1968; Fielder, 1972; Momot et al. 1978). Most individuals will mate during their first fall, producing a brood the following spring. Though many survive to produce a second brood the next year, the majority of F. propinquus who mate in their first year of life die as yearlings (Crocker and Barr 1968). Although the average life expectancy of F. propinquus is about 2 years of age (Van Deventer 1932; Crocker and Barr 1968; Corey 1988), in rare instances individuals have been found to live up to 4 years (Corey 1988).

Means of Introduction: This species was likely introduced through bait releases by anglers (Capelli and Munjal 1982).

Status: Though native to the eastern portion of Lake Superior, F. propinquus has expanded its range to the western portion of the lake (Peters et al. 2014). Faxonius propinquus is abundant in lakes of northern Wisconsin (Magnuson et al. (1975; Hobbs 1989).

Impact of Introduction: Magnuson et al. (1975) presented data indicating that introduced crayfishes (F. propinquus, F. rusticus, F. virilis) reduced the abundance of macroinvertebrates that serve as important fish forage. Additionally, the crayfish provided only a marginal food source to game fishes, and they threatened to eliminate native crayfish species (Magnuson et al.1975). Faxonius propinquus have been documented consuming Lake Sturgeon (Acipenser fulvescens) and Lake Trout (Salvelinus namaycush) eggs within the Great Lakes region (Nichols et al. 2003; Jonas et al. 2005).

Remarks: Range expansion of the nonnative Rusty Crayfish (F. rusticus) threatens local populations of F. propinquus through hybridization and displacement (Berrill 1985; Perry et al. 2002).

References: (click for full references)

Capelli, G.M., and B.L. Munjal. 1982. Aggressive interactions and resource competition in relation to species displacement among crayfish of the genus orconectes. Journal of Crustacean Biology 2(4):486-492. https://www.jstor.org/stable/1548090

Berrill, M., and B. Chenoweth. 1982. The burrowing ability of nonburrowing crayfish. The American Midland Naturalist 108(1):199-201. http://www.jstor.org/stable/2425310

Berrill, M. 1985. Laboratory induced hybridization of two crayfish species, Orconectes rusticus and O. propinquus. Journal of Crustacean Biology 5:347-339.

Bovbjerg, R.V. 1952. Comparative ecology and physiology of the crayfish, Orconectes propinquus and Cambarus fodiens. Physiological Zoology 25(1):34-56. https://www.jstor.org/stable/30160911

Corey, S. 1988. Comparative life histories of two populations of the introduced crayfish Orconectes rusticus (Girard, 1852) in Ontario. Crustaceana 55(1):29-38.

Crandall, K.A. and S. De Grave. 2017. An updated classification of the freshwater crayfishes (Decapoda: Astacidea) of the world, with a complete species list. Journal of Crustacean Biology 37(5):615-653. https://doi.org/10.1093/jcbiol/rux070

Crocker, D.W., and D.W. Barr. 1968. Handbook of the crayfishes of Ontario. University of Toronto Press, Toronto, Ontario.

Fielder, D.D. 1972. Some aspects of the life histories of three closely related crayfish species, Orconectes obscurus, O. sanborni, and O. propinquus. The Ohio Journal of Science 72(3):129-145. http://hdl.handle.net/1811/5691

Fitzpatrick, J.F., Jr. 1967. The Propinquus group of the crawfish genus Orconectes (Decapoda: Astacidae). The Ohio Journal of Science 67(3):129-172. http://hdl.handle.net/1811/5295

Guarino, J., C. Gastador, and E. Miller. 2012. Field guide to the crayfish of the White River watershed, east-central Vermont. White River Partnership and Verdana Ventures, LLC, Randolph, VT. http://whiteriverpartnership.org/wp-content/uploads/2014/04/Field-Guide-to-the-Crayfish-of-the-White-River-Watershed.pdf

Hazlett, B.A. 1994. Alarm responses in the crayfish Orconectes virilis and Orconectes propinquus. Journal of Chemical Ecology. 20, 1525-1535.

Hobbs, H.H. 1989. An illustrated checklist of the American crayfishes (Decapoda: Astacidae, Cambaridae, and Parastacidae). Smithsonian Institution Press. Washington, D.C.

Hobbs, H.H, J.P. Jass, J.V. Huner. 1989. A review of global crayfish introductions with particular empahsis on two North American species (Decapoda, Cambaridae). Crustaceana 53(3):299-316.

Jonas, J.L., R.M. Claramunt, J.D. Fitzsimons, J.E. Marsden, and B.J. Ellrott. 2005. Estimates of egg deposition and effects of lake trout (Salvelinus namaycush) egg predators in three regions of the Great Lakes. Canadian Journal of Fisheries and Aquatic Sciences 6(10):2254-2264. https://doi.org/10.1139/f05-141

Krugner-Higby, L., D. Haak, P. T. J. Johnson, J. D. Shields, W. M. Jones III, K. S. Reece, T. Meinke, A. Gendron, and J. A. Rusak. 2010. Ulcerative disease outbreak in crayfish Orconectes propinquus linked to Saprolegnia australis in Big Muskellunge Lake,Wisconsin. Diseases of Aquatic Organisms 91:57-66.

MacIsaac, H.J. 1994. Size-selective predation on zebra mussels (Dreissena polymorpha) by crayfish. Journal of the North American Benthological Society 13(2):206-216.

Momot, W.T., H. Gowing, and P.D. Jones. 1978. The dynamics of crayfish and their role in ecosystems. American Midland Naturalist 99:10-35.

Nichols, S.J., G. Kennedy, E. Crawford, J. Allen, J. French III, G. Black, M. Blouin, J. Hickey, S. Chernyak, R. Haas, and M. Thomas. 2003. Assessment of lake sturgeon (Acipenser fulvenscens) spawning efforts in the lower St. Clair River, Michigan. Journal of Great Lakes Research 29(3):383-391. https://doi.org/10.1016/S0380-1330(03)70445-6

Ortmann, A.E. 1906. The crawfishes of western Pennsylvania. The Annals of the Carnegie Museum 3:387-406.

Page, L.M. 1985. The crayfishes and shrimps (Decapoda) of Illinois. Volume 33. State of Illinois Department of Energy and Natural Resources, Champaign, IL. https://www.ideals.illinois.edu/bitstream/handle/2142/44052/Bulletin33%284%29.pdf?sequence=2&isAllowed=y

Peters, J.A., M.J. Cooper, S.M. Creque, M.S. Kornis, J.T. Maxted, W.L. Perry, F.W. Schueler, T.P. Simon, C.A. Taylor, R.F. Thoma, D.G. Uzarski, and D.M. Lodge. 2014. Historical changes and current status of crayfish diversity and distribution in the Laurentian Great Lakes. Journal of Great Lakes Research 40(1):35-46.

Perry, W.L., D.M. Lodge, and J.L. Feder. 2002. Importance of hybridization between indigenous and nonindigenous freshwater species: an overlooked threat to North American biodiversity. Systematic Biology 51(2):255-275. http://sysbio.oxfordjournals.org/content/51/2/255.full.pdf

Schanoist S.C. 2016. The crayfish of Nebraska. The Nebraska Game and Parks Commission. Lincoln, Nebraska.

Taylor, C.A., G.A. Schuster, and D.B. Wylie. 2015. Field guide to crayfishes of the Midwest. Illinois Natural History Survey, Champaign, IL.

U.S. Fish and Wildlife Service. 2015. Northern Clearwater Crayfish (Orconectes propinquus) ecological risk screening summary. https://www.fws.gov/fisheries/ans/erss/highrisk/Orconectes-propinquus-ERSS-June-2015.pdf (Accessed: October 12, 2018).

Van Deventer, W.C. 1937. Studies on the biology of the crayfish Cambarus propinquus Girard. Illinois Biological Monographs 15(3):1-67.

Other Resources:
US Fish and Wildlife Ecological Risk Screening Summary for Northern Clearwater Crayfish

Great Lakes Waterlife

Author: Procopio, J., N. Boucher, A. Elgin

Revision Date: 11/3/2023

Citation Information:
Procopio, J., N. Boucher, A. Elgin, 2024, Faxonius propinquus (Girard, 1852): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=2249, Revision Date: 11/3/2023, Access Date: 6/20/2024

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 [6/20/2024].

Contact us if you are using data from this site for a publication to make sure the data are being used appropriately and for potential co-authorship if warranted.

For general information and questions about the database, contact Wesley Daniel. For problems and technical issues, contact Matthew Neilson.