Key to the Crayfishes of the Chattooga/Little River Systems

1a. Claws long and slender; mesial margin of the palm nearly as
twice as long as width of palm (Fig. 1C).......Procambarus lophotus
1b. Claws appear more robust; length of mesial margin of the palm
equal to or less than width of palm (Figs. 1A, B).................go to 2

Figure 1. Representative claw shapes of A) Cambarus sp.;
B) Orconectes sp.; and C) Procambarus lophotus.

2a. Outside edge of claw black; black spot on palm near junction
of moveable finger.............................................................go to 3
2b. Outside edge of claw not black; no black spot on palm near
junction of moveable finger................................................go to 4

3a. Rear margin of abdominal segments red (only one record of this species from the Chattooga River system)......Orconectes spinosus
3b. Rear margin of abdominal segments
brownish.................................................Orconectes erichsonianus

4a. Claws gaping when fingers are closed
(Fig. 2A)......................................................Cambarus longirostris
4b. Claws not gaping when fingers are closed (Fig. 2B)...........go to 5

Figure 2. Dorsal view of crayfish claws indicating A) gaping and
B) non-gaping condition.  Modified from Hobbs (1981).

5a.  Spine extending beyond edge of uropod
(Fig. 3A)......................................................Cambarus acanthura
5b.  Spine not extending beyond edge of uropod (Fig. 3B).....go to 6

Figure 3. Position of spine on mesial ramus of uropod.  A) Spine extending past edge of uropod; B) spine not extending past edge of uropod.  Modified from Hobbs (1981).

6a. Single, well developed, sharp cervical spine (Fig. 4B)........go to 7
6b. At most single cervical tubercle, or nothing........................go to 8

Figure 1. Lateral view of crayfish indicating number and position of cervical spines. Modified from Hobbs (1981).

7a. Margins of rostrum and claw tubercles bright red...Cambarus scotti
7b. No bright red on crayfish, although the tips of claws may be orangish...............................................Cambarus latimanus, in part


Figure 5. Dorsal view of A) Cambarus striatus, B) C. unestami, and C. latimanus indicating eye size, rostrum shape, and areola width. From Hobbs (1981; 1989).

8a. Areola usually more than 9 times as long as broad (Fig. 5A);
rostrum typically somewhat blunt; some populations with distinct abdominal stripes; cervical spines never present....Cambarus striatus
8b. Areola usually less than 9 times as long as broad (Fig. 5B, C);
rostrum tapering; some individuals with indistinct abdominal stripes; cervical spines present or not present....................................go to 9

9a. Claw tips orangish............................Cambarus latimanus, in part
9b. Claw tips not orangish....................................Cambarus unestami