Morphological Description

The PCC is a small crayfish, growing to about two inches (body length minus claws). Detailed morphological descriptions of the PCC are provided by Hobbs (1942), Keppner and Keppner (2001), and Breinholt and Moler (2016)(Figure 2.6). The color pattern consists of a medium-dark brown background color, lighter brown mid-dorsal stripe, and darker brown dorsolateral stripes (Figure 2.1). The lower lateral carapacial surfaces are lighter brown with reddish-brown spots.

PCC morphological characters.
Figure 2.6. Procambarus econfinae (from Hobbs 1942): 16. Dorsal view of carapace, 17. Upper surface of cheliped, 18. Annulus ventralis of female, 19. Lateral view of first pleopod of Form II male, 20. Lateral view of first pleopod of Form I male.

Some Procambarus (Leconticambarus) species are quite similar in size and appearance and can be difficult to separate from one another based only on the general appearance or color. Accurate identification of the species of crayfish in the genus Procambarus requires the examination of the external reproductive structures (gonopods), preferably those of the reproductively competent Form I male (Figure 2.6 and 2.7). This is best achieved with the aid of a stereoscopic microscope. The PCC is distinguished from related species of Procambarus (P. kilbyi, P. apalachicolae, P. hubbelli) that occur outside its range by the shape and arrangement of the terminal processes of the first pair of pleopods of the reproductive males (Hobbs 1942, Keppner and Keppner 2001, 2014).

PCC male vs. female.
Figure 2.7. Male and female Panama City crayfish. Male (left), as evidenced by the modified pleopods and female (right) as evidenced by the annulus ventralis. Credit FWC (2017).

Hobbs (1942a) stated that males in Procambarus alternate between a sexually competent form (Form I males) and a sexually incompetent form (Form II males). It is the anatomy of the first pair of pleopods of the Form I male that provides the best identification to species, because the keys to Procambarus (Leconticambarus) species are based primarily, if not entirely, on the morphology of the first pleopod of the Form I male.