Faxonius cristavarius

Based on Crandall and De Grave (2017), the representatives of Orconectes form at least two distinct groups. The nominal group (the "cave Orconectes") form a monophyletic group that is more closely related to members of Cambarus, while the remaining "Orconectes" are more closely related to Barbicambarus, Creaserinus, and other species of Cambarus (Crandall and Fitzpatrick 1996, Fetzner 1996). As the type species of Orconectes, Orconectes inermis Cope, 1872, belongs to the cave-dwelling group, the genus is herein restricted to just those taxa. The surface-dwelling taxa now excluded from Orconectes sensu stricto are herein placed in the resurrected genus Faxonius Ortmann, 1905a, the oldest available name previously considered to be a synonym of Orconectes Cope, 1872.

Formerly part of the Orconectes juvenilis complex (Taylor 2000).

Revision of the Orconectes juvenilis complex by Taylor (2000) reveals this newly described species to occur widely from the upper Cumberland River drainage in southeastern Kentucky east to the upper New River drainage of western North Carolina and Elk River drainage of West Virginia, and upper New and Tennessee River drainages in Virginia. This species has a large distribution covering a large part of the U.S.A. There are no major threats known to be impacting this abundant species.

Revision of the Orconectes juvenilis complex by Taylor (2000) reveals this newly described species to occur widely from the upper Cumberland River drainage in southeastern Kentucky east to the upper New River drainage of western North Carolina and Elk River drainage of West Virginia, and upper New and Tennessee River drainages in Virginia.

In North Carolina it occurs throughout most of the New River basin and has been introduced into the Yadkin-Pee Dee River basin (Cooper, 2005). LeGrand et al. (2006) cites the New River drainage in North Carolina. McGrath (1998) found it common to abundant at all 27 sites sampled in the New River basin, North Carolina and Simmons and Fraley (2010) found it in 7 of 13 sites surveyed. In Kentucky, it is widespread and common in the upper Cumberland, Kentucky, and Licking River drainages and in the Big Sandy drainage; and also occurs in the Little Sandy River and Tygarts Creek drainages of eastern Kentucky (Taylor and Schuster, 2004). Peake et al. (2004) collected this species in the upper Cumberland and upper Kentucky River basins in Kentucky. In Ohio, it is confined to the extreme south-central counties (Thoma and Jezerinac, 2000). In West Virginia, it is prevalent throughout the southwestern Ohio River basins and James River drainage, and sporadically distributed throughout portions of teh Kanawha River system (Loughman and Welsh, 2010).

It is unlikely that there are any major threats impacting upon this species. Various studies have shown that introduced O. rusticus has a higher growth rate than its congeners contributing to its dominance over other crayfish species (Hill et al., 1993; Mather and Stein, 1993); however studies by Pintor and Sih (2009) indicate higher growth rates is a characteristic of introduced but not native populations of O. rusticus (higer foraging activity and exploitation of bait of introduced versus native populations; as well as bait piracy).