Procambarus parasimulans (Hobbs and Robison)


Map [dots indicate Ouachita National Forest collection sites]

Recognition Characters: Rostrum without marginal spine and median carina. Carapace lacking cervical spine or tubercle. Areola averages 6.6 times as long as broad and constituting about 32.5 percent of total length of carapace. Branchiostegal spine reduced to weak tubercle. Ventral surface of chela strongly tuberculate, tubercles present along proximal half of ventral surface of dactyl. Ischium of third periopod of first form male with simple, strong hook overreaching basioischial articulation. Coxa on fourth periopod lacking caudomesial boss. First pleopods of first form males reaching coxae of third periopods, symmetrical, bearing proximomesial spur at caudal proxiomomesial angle and subtruncate cephalic shoulder at base of terminal elements, lacking subbterminal setae; terminal elements consisting of (1) long slightly curved mesial process reaching beyond other elements; (2) small, weakly curved, cephalodistally directed cephalic process at cephalic base of mesial process, (3) similarly disposed, strongly cornified clawlike central projection arising from between mesial and caudal processes; and (4) very conspicuous caudal process rounded, spatulate, and disposed cephalodistally.

Coloration: Carapace pale tan dorsally fading to cream ventrolaterally. Dark brown stripe on ventral flank or postorbital ridge and another extending ventrally across orbital and antennal areas, setting off marginal, subtriangular cream marking on antennal and upper anteroventral branchiostegal regions. Abdomen-like carapace, tan dorsally fading ventrally to very pale tan and marked by two pairs of scalloped dark stripes, the more dorsal one darker and extending caudally. Dorsal surface of cheliped much darker than ventral, dark brown reticulations most conspicuous along dorsal edge and on distal border of merus.

Size: Adults are approximately 4 to 5 inches (101-127 mm) in total length.

Habitat: This burrower is found in floodplain areas and occasionally wanders out into temporary pools and backwater pools of small streams.

General Range: An Arkansas endemic (Robison and Allen, 1995) occurring in the southwestern part of Arkansas where it has been found in the Red and Ouachita River basins and three localities in the Arkansas River watershed (Hobbs and Robison, 1982; 1989).

Comments: The type locality is an unnamed tributary of Prairie Creek 10.2 miles (16.4 km) east of Bismark, Hot Spring County, on St. Hwy. 84 (Hobbs and Robison, 1988).

Although this species was not collected during the study, it has been collected a single time on the ONF from the site of Station 186. Previously, Dr. A. P. Blair of Tulsa University, while looking for paleback darters, collected one female P. parasimulans 0.9 mile (1,4 km) west of Caddo Gap, Montgomery County, on 23 November 1962 (Hobbs and Robison, 1988). A visit to this site yielded no crayfishes. The species is also known to occur more commonly just south of the ONF in Arkansas near the communities of Kirby and Daisy (Hobbs and Robison, 1988; H. W. Robison, personal collections).