Crayfishes (Decapoda: Cambaridae) of Oklahoma: identification, distributions, and natural history Author Morehouse, Reid L. Author Tobler, Michael text Zootaxa 2013 3717 2 101 157 journal article 10.11646/zootaxa.3717.2.1 fad4163f-156b-4f1a-a5e9-c9f48df52e0a 1175-5326 248539 C8CDC011-974C-48B4-9E03-88F570EEDE13 Procambarus curdi Reimer, 1975 : Red River Burrowing Crayfish General charateristics. Adults rarely exceed 100 mm in total length. The carapace is ovate with reduced or no cervical spines and the areola is open. The rostrum is lacking lateral spines and has a short acumen with a troughlike depression. Chelae are subcylindrical, long, and the mesial surface of palm has tubercles. In form I males, gonopods reach the base of the third pereiopods and terminate in four terminal processes. Central projection is corneous, subtriangular, and flattened lateromesially. In females, annulus ventralis is subovate, and the cephalic half has a broad V-shaped trough (Reimer, 1975). Life coloration. Background color olive-green to light bluish gray. Highlights of red are present on the tail, cervical groove, and on chelae ( Figure 77 ). Chelae usually are a lighter gray or with a blue tint. Two rows of darker blotches run longitudinally on the dorsal side of abdomen. Ventral side is whitish. Similar species. In Oklahoma, P . curdi closely resembles P . simulans . Procambarus curdi can be differentiated from P . simulans by the caudal process of the gonopod, which is flattened lateromesially rather than cephalocaudally as in P . simulans (Reimer, 1975) . Distribution and habitat. Procambarus curdi occurs in the Red River drainage of southeastern Oklahoma and southwestern Arkansas, as well as the Brazos River drainage in Texas (Johnson & Johnson, 2008). Procambarus curdi generally occurs in semi-permanent water bodies such as ditches, backwater pools, and intermittent streams. It can also be found in open water during the juvenile release period. Procambarus curdi will burrow when water sources start to recede. In Oklahoma, P . curdi is found in the southeastern counties along the Red River. Our ecological niche model indicates that P . curdi is mainly confined to the Red River drainage, although one area just north of the Ouachita Mountains may provide suitable environmental condition conditions ( Figure 78 ). Life history. Procambarus curdi appears to be a secondary burrower as the majority of collections known were from burrows located on the bank of streams or rivers (Reimer, 1975). Males (form I and II) and females have been collected year round from burrows. To our knowledge no ovigerous females or females with young have been collected in Oklahoma. Procambarus curdi is more active and leaves burrows on warm humid nights usually after rain events. Syntopic species. Procambarus simulans . Conservation status. AFS: Currently Stable; Heritage Rank: Widespread (G5); IUCN: Least Concern; ODWC: Not Listed. Additional resources. Hobbs (1990).