Dichotomous Key to the Crayfishes of the Ochlockonee River System

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

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

2a. Rostrum long and pointed with marginal spines and acumen present (Fig. 2A).......................................Procambarus paeninsulanus
2b. Rostrum short and rounded with no marginal spines and no acumen...............................................................Procambarus talpoides

Figure 2. Rostrum shape of A) Procambarus paeninsulanus and B) P. talpoides.  Modified from Hobbs (1981).