Crayfishes of Georgia
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 Altamaha River System

1a. Claw tubercles reddish or orangish.......Procambarus troglodytes
1b. Claw tubercles not reddish or orangish.............................go to 2

2a. Two large, dark spots on upper sides of carapace....................................................Procambarus seminolae
2b. No large, dark spots on upper sides of carapace..............go to 3

3a. Long tapering rostrum often with marginal spines; small cervical spines or tubercles on either side of carapace.......Procambarus lunzi
3b. Rostrum shorter, no marginal spines; no cervical spines or tubercles................................................................................go to 4

4a. Areola more than 10 times as long as broad....................go to 5
4b. Areola less than 10 times as long as broad.......................go to 7

5a. Color greenish with red highlights...........Procambarus pygmaeus
5b. Color brownish with pink or bluish hues.............................go to 6

  advena caritus web

Figure 1. A-B) gonopods of Form II and Form I male Procambarus caritus indicating fingernail-like central projection and lack of cephalic process; C-D) gonopods of Form II and Form I male Procambarus advena indicating beak-like central projection and presence of cephalic process. Modified from Hobbs (1981).

6a. Central projection of male gonopod fingernail-like, cephalic process absent (Figs. 1A, B)......................Procambarus caritus
6b. Central projection of male gonopod beak-like, cephalic process present
(Figs. 1C, D)..................................................Procambarus advena

 babatus deficiens web

Figure 2. A-C: Procambarus barbatus and D-E: Procambarus pubischelae deficiens. A and D) annulus ventralis indicating presence or absence of tuberculation; B and E) gonopod of Form II male; C and F) gonopod of Form I male. Modified from Hobbs (1981).

7a. Female annulus ventralis wing-like with extensive tuberculation
(Fig. 2A); male gonopod tapers to end
(Figs. 2B, C)...............................................Procambarus barbatus
7b. Female annulus ventralis with tuberculation lacking
(Fig. 2D); male gonopod squared off, or convex distally
(Figs. 2E, F)..............................Procambarus pubischelae deficiens

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