Cambarus subterraneus Hobbs, 1993: Delaware County Cave Crayfish General charateristics. A white (albinistic) crayfish with small, unpigmented eyes, and long slender chelae. Adults rarely exceed 50 mm in total length. The carapace lacks cervical spines. The rostrum is broadest at its base and exhibits small marginal spines. The body surface and pereiopods are covered in conspicuous stiff setae, which likely serve as sensory organs in the dark cave environment. In form I males, the gonopods terminate in two terminal processes recurved at angles greater than 90°, and the central projection is moderately long and slender. In females, the annulus ventralis is subsymmetrical in outline, and the caudal part is slightly movable. The cephalic half of the annulus ventralis is traversed by a deep submedian longitudinal trough (Hobbs, 1993). Life coloration. Off-white to pinkish-white, especially in the abdominal region (Figure 35). Newly molted individuals are nearly all white. Smaller individuals can appear somewhat translucent. Similar species. Cambarus subterraneus closely resembles C. tartarus, the only other cave crayfish in Oklahoma. It can be differentiated from C. tartarus by the central projection of the gonopod, where Cambarus subterraneus ’ central projection is slender and tapers towards the end, while C. tartarus ’ central projection is heavy and non-tapering. Furthermore, C. subterraneus is found in only three caves, all of which are disjunct from the caves with C. tartarus. Distribution and habitat. Cambarus subterraneus is a tertiary burrower and has been recorded in three caves (Twin, Star, and Jail) in Delaware County, Oklahoma (Figure 36). These caves have limestone bottoms covered with fine silt. Life history. Form I males have been collected from May through October in the three different caves (Hobbs, 1993). Females with young have not been observed, but one ovigerous female was found in the late 1980’s (Puckette, 1986). Syntopic species. No syntopic crayfish species are known at this time. Conservation status. AFS: Endangered; Heritage Rank: Critically Imperiled (G1); IUCN: Critically Endangered; ODWC: Tier 1. Additional resources. Jones & Bergey (2005); Taylor et al. (2004).

Published as part of Morehouse, Reid L. & Tobler, Michael, 2013, Crayfishes (Decapoda: Cambaridae) of Oklahoma: identification, distributions, and natural history, pp. 101-157 in Zootaxa 3717 (2) on pages 123-124, DOI: 10.11646/zootaxa.3717.2.1, http://zenodo.org/record/248539