Faxonius juvenilis
(Hagen, 1870)
Common Name:
Kentucky River crayfish
Synonyms and Other Names:
Orconectes juvenilis (Hagen, 1870). Faxonius juvenilis underwent a reclassification in August 2017, changing the genus of non-cave dwelling Orconectes to Faxonius (Crandall and De Grave 2017).
Identification:
Orconectes juvenilis is 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 black bands. The rostrum is characterized as moderately excavated without median carina with margins slightly curved and converging, and terminating in spines. Edges of abdominal segments, articulation joints, and lateral edge of chela are red or orange. Ventral surfaces are a cream to white color. Form I males have two long thin elements on gonopod (Taylor 2000; Taylor et al. 2015). O. juvenilis and O. rusticus are morphologically similar with both having blade-like mandibles, which separates them from the rest of the “juvenilis complex” that have serrated mandibles. O. juvenilis differs from O. rusticus in length of the first gonopod and the ratio of the central projection to gonopod length (Taylor 2000; Amandus 2014).
Size:
Maximum size 81.5 mm in total length (Taylor and Schuster 2004).
Native Range:
Range as determined by Taylor (2000) is now restricted to a narrow stretch of the Ohio River drainage of northcentral Kentucky and southeastern Indiana. Orconectes juvenilis can be found in portions of the Kentucky River drainage, upper Cumberland (above the falls), the Rockcastle, and the Salt River drainages in Kentucky.
Ecology:
Orconectes juvenilis is a habitat generalist which inhabits small streams to rivers with mud, gravel, cobble, boulder, or fractured bedrock substrates. The species can be found commonly under large rocks and occasionally in wood debris or undercut banks (Taylor 2000; Taylor and Schuster 2004; Taylor et al. 2015)
Means of Introduction:
This species has been introduced by deliberate stocking (Chucholl 2013) and through bait buckets releases.
Status:
Established
Great Lakes Impacts:
Remarks:
This species was formerly part of a complex but is now recognized as a distinct species by Taylor (2000). 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 reference list)
Author:
Daniel, W.M.
Contributing Agencies:
Revision Date:
6/14/2017
Citation for this information:
Daniel, W.M., 2025, Faxonius juvenilis (Hagen, 1870): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI, https://nas.er.usgs.gov/queries/GreatLakes/FactSheet.aspx?Species_ID=2904, Revision Date: 6/14/2017, Access Date: 1/5/2025
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.