Crayfishes of Georgia Overview List of Georgia Species Species Lists by Drainage Crayfish Identification Keys by Drainage Ecology and Life History Links and Other Useful Information Glossary
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Dichotomous Key to the Crayfishes of the Conasauga River System

1a. Two cervical spines (Fig. 1A).................Procambarus spiculifer
1b. One or zero cervical spines (Fig. 1B)................................go to 2

cervical spines

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

2a. Claws long and slender; mesial margin of the palm nearly as
twice as long as width of palm (Fig. 1A).......Procambarus lophotus
2b. Claws appear more robust; length of mesial margin of the
palm equal to or less than width of palm (Figs. 1A, B)..........go to 3

claw shapes webFigure 2. Representative claw shapes of A) Cambarus sp.;
B) Orconectes sp.; and C) Procambarus lophotus.

3a. Single, well developed, sharp cervical spine (Fig. 1B)......go to 4
3b. At most single cervical tubercle, or nothing......................go to 6

4a. Lateral edge of claw black, fingers of claw with black subapical bands pigment on claws..................................Orconectes spinosus
4b. No black pigment on claws............................................go to 5

5a. Margins of rostrum and claw tubercles bright
red.....................................................................Cambarus coosae
5b. No bright red on crayfish; tips of claws
orangish..............................................Cambarus latimanus, in part

claws web

Figure 3. Dorsal view of crayfish claws indicating A) gaping and
B) non-gaping condition.  Modified from Hobbs (1981).

6a. Claws gaping when closed (Fig. 3A).........Cambarus manningi
6b. No black pigment present on claws................................go to 7

 tails web

Figure 4. 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).

7a. Spine extending past end of uropod (Fig. 4A)..................go to 8
7b. Spine not extending past end of uropod (Fig. 4B)............go to 9

8a.  Overall color blue, especially on claws; two rows of tubercles on the mesial margin of the palm............................Cambarus cymatilis
8b. Overall color greenish to reddish-brown; more than two rows of tubercles along the mesial margin of palm........Cambarus acanthura

 

jug dep claws web 

Figure 5. Dorsal view of crayfish claws indicating A) single row of tubercles along mesial margin of palm and B) more than one row of tubercles along mesial margin of palm.  Modified from Hobbs (1981).

9a. Claws with single row of tubercles along mesial margin of palm
(Fig 5A)...............................................................................go to 10
9b. Claws with two rows of tubercles along mesial margin of palm
(Fig. 5B)..............................................................................go to 11

10a. Claws with single serrate row of tubercles along mesial margin
of palm; claws usually with long setae on the
fingers....................................................Cambarus conasaugaensis
10b. Claws with single flattened row of tubercles along mesial margin
of palm; no obvious setae on fingers.......Cambarus bartonii bartonii

striatus latimanus dorsal web

Figure 6. Dorsal view of A) Cambarus striatus showing typically narrower areola than areola of B) Cambarus latimanus.  Modified from Hobbs (1981).

11a. Areola usually more than 9 times as long as broad (Fig. 6A); rostrum typically somewhat blunt; some populations with distinct abdominal stripes; cervical spines never present.....Cambarus striatus
11b. Areola usually less than 9 times as long as broad (Fig. 6B);
rostrum tapering; some individuals with indistinct abdominal stripes; cervical spines sometimes present, especially in
juveniles.................................................Cambarus latimanus, in part

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