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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.

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Common name: Spiny stream crayfish

Synonyms and Other Names: Orconectes cristavarius (Taylor, 2000). Faxonius cristavarius underwent a reclassification in August 2017, changing the genus of non-cave dwelling Orconectes to Faxonius (Crandall and De Grave 2017). This species was previously known as O. spinosus by Hobbs (1981) (Taylor 2000; Loughman and Welsh 2010). 

Taxonomy: available through www.itis.gov

Identification: This species is described by Taylor (2000) as being a brown to tan to olive green color with dorsal surfaces of chelae covered with small dark flecks. The fingers of chelae are tipped in orange and followed proximally by thin black bands. Sometimes the first abdominal segment has a dark brown U-shaped saddle centered at the caudal margin. The rostrum is characterized as flat with margins thickened, terminating in upturned corneous spine.  Edges of abdominal segments, articulation joints, and lateral edge of chela are red or orange. Ventral surfaces are a cream to white color.

Orconectes cristavarius differs from all other members of the genus Orconectes by possessing a unique combination of chelae, serrated mandibles, and antennal scale characters (see Taylor 2000).

Size: Maximum size 84.0 mm in total length (Taylor and Schuster 2004).

Native Range: Orconectes cristavarius is found across the Central Appalachians in the middle Ohio River drainage from the Cumberland River system in Kentucky and Tennessee east to the New River basin in North Carolina and Virginia (Taylor 2000; Taylor and Schuster 2004).

• Kentucky-it is widespread and common in eastern Kentucky in the upper Cumberland, Kentucky, Licking River, Little Sandy, Tygarts Creek and Big Sandy drainages (Taylor 2000; Taylor and Schuster 2004).
• North Carolina –it is throughout most of the New River basin (Taylor 2000; Taylor and Schuster 2004 Cooper 2005; LeGrand et al. 2006).
• Ohio- it is confined to Lower Scioto (Thoma and Jezerinac 2000).
• Tennessee- it is throughout the upper Cumberland, Clinch, and Powell Rivers (Taylor 2000; Taylor and Schuster 2004).
• Virginia- it if found in the upper New and Tennessee River drainages (Taylor 2000; Taylor and Schuster 2004).
• West Virginia- it is prevalent throughout the southwestern Ohio River basins and James River drainage, and sporadically distributed throughout portions of the Kanawha River system (Taylor 2000; Taylor and Schuster 2004; Loughman and Welsh 2010).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology: Orconectes cristavarius occurs in creeks and small to medium-sized rivers with moderate-to low- velocity and substrates of cobble and gravel (Taylor 2000; Loughman et al. 2009). Adults were usually found under large slab rocks or cobble in various parts of the stream: midstream and along the stream margin (Simmons and Fraley 2010); shallow riffles or runs (Taylor 2000); or detritus beds in pool thalwegs (Loughman et al. 2009). In West Virginia, large numbers of adults were seen in backwater pools during late summer (Loughman et al. 2009). Juveniles were often collected from beneath undercut banks or shallow pools (Loughman et al. 2009; Simmons and Fraley 2010).

Fortino and Creed (2007) demonstrated that O. cristavarius was the dominate crayfish species in the downstream reaches of the South Fork of the New River, NC. It was hypothesized that differences in escape behavior from rock bass (Ambloplites rupestris) and growth rate may have contributed to the differences in distribution between Cambarus chasmodactylus as the dominant species in third-order tributaries and O. cristavarius as the dominant species in the mainstem fourth-order South Fork. 

Means of Introduction: Most likely from bait bucket releases.

Status: Established

Impact of Introduction: Loughman et al. (2009) has found that Orconectes cristavarius can be the dominant orconectid in a stream, with exception of O. rusticus which has a higher growth rate than its congeners contributing to its dominance over other crayfish species (Hill et al. 1993) including O. cristavarius (Pintor and Sih 2009). It is probable that O. cristavarius can displace other native crayfish species since it has a high growth rate and anti-predator behaviors making it a better competitor (Fortino and Creed 2007).

Remarks: This species is formerly part of the Orconectes juvenilis complex (Taylor 2000).

In North Carolina, Orconectes cristavarius is commonly sympatric with C. robustus, C. chasmodactylus, and C. bartonii. Form I males were collected during mid-October in water temperatures ranging from 11–17 °C and juveniles were also collected in mid-October (Simmons and Fraley 2010).

The “juvenilis complex” includes six species of the subgenus Procericambarus: Orconectes cristavarius (Taylor 2000), O. juvenilis (Hagen 1870), O. putnami (Girard 1852), O. ronaldi (Taylor 2000), O.rusticus and O. spinosus (Bundy 1887).

References: (click for full references)

Cooper, J.E. 2005. Crayfishes occurring in North Carolina. North Carolina State Museum of Natural Sciences, Raleigh, NC

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.

Fortino, K., & Creed, R. P. 2007. Abiotic factors, competition or predation: what determines the distribution of young crayfish in a watershed?. Hydrobiologia. 575(1): 301-314.

Hill, A.M., D.M., Sinars, and Lodge, D.M. 1993. Invasion of an occupied niche by the crayfish Or- conectes rusticus: potential importance of growth and mortality. Oecologia. 94:303-306

LeGrand, H.E., Jr., S.P. Hall, S.E. McRae, and J.T. Finnegan. 2006. Natural Heritage Program List of the Rare Animal Species of North Carolina. North Carolina Natural Heritage Program, Raleigh, North Carolina. 104 pp.

Loughman, Z.J., Simon, T.P., and Welsh, S.A. 2009. West Virginia crayfishes (Decapoda: Cambaridae): observations on distribution, natural history, and conservation. Northeastern Naturalist. 16(2): 225-238.

Loughman, Z. J., & Welsh, S. A. 2010. Distribution and conservation standing of West Virginia crayfishes.

McGrath, C. 1998. New River basin aquatic inventory. North Carolina Wildlife Resources Commission, Nongame Project Report, Raleigh, NC

Pintor, L. M., and Sih, A. 2009. Differences in growth and foraging behavior of native and introduced populations of an invasive crayfish. Biological Invasions. 11(8): 1895-1902.

Simmons, J.W., & Fraley, S.J. 2010. Distribution, status, and life-history observations of crayfishes in western North Carolina.

Taylor, C.A. 2000. Systematic studies of the Orconectes juvenilis complex (Decapoda: Cambaridae), with descriptions of two new species. Journal of Crustacean Biology. 20(1): 132-152.

Taylor, C. A., and Schuster, G. A. 2004. The crayfishes of Kentucky. Illinois Natural History Survey Special Publication. No.28. vii+219 pp.

Thoma, R.F. and R.E. Jezerinac. 2000. Ohio crayfish and shrimp atlas. Ohio Biological Survey Miscellaneous Contribution 7: 1-28

Other Resources:
Natureserve: Spiny Stream Crayfish

Author: Daniel, W.M.

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.