Orconectes lancifer (Hagen, 1870)

Morehouse, Reid L. & Tobler, Michael, 2013, Crayfishes (Decapoda: Cambaridae) of Oklahoma: identification, distributions, and natural history, Zootaxa 3717 (2), pp. 101-157 : 128-129

Orconectes lancifer (Hagen, 1870) : Shrimp Crayfish

General charateristics. Adults rarely exceed 76 mm in total length. The carapace has strong cervical spines, is nearly equal in length relative to the abdomen, and the areola is closed. The rostrum has a deep trough-like depression, and the margins are nearly straight terminating in spines or tubercles at the base of an extremely long acumen. Chelae are slender with short fingers, dactyl shorter than the length of the palm, and they are lacking longitudinal ridges and tubercles. In form I males, gonopods terminate into two very short processes. The mesial process is non-corneous and equal in length or slightly longer than central projection. In females, the annulus ventralis lacks a well-developed fossa (Taylor & Schuster, 2004).

Life coloration. The background color is reddish-brown to gray, with specks of light to dark brown creating a mottled appearance ( Figure 51 ). The ventral side is pale-yellow to white.

Similar species. The long acumen and gonopods in form I males having two short truncated terminal processes are characteristics that no other crayfish in Oklahoma possesses.

Distribution and habitat. Orconectes lancifer occurs from southwestern Illinois and southeastern Missouri, southward along the Mississippi River to southeastern Oklahoma, eastern Texas, and Louisiana. In Oklahoma, O. lancifer is only known from two localities in McCurtain County, an oxbow lake of the Red River and a pond at Red Slough National Wildlife Refuge. The pond in at Red Slough was drained several years ago, and since draining this species has not been detected. Additionally, in 2005 we visited the oxbow lake but did not detect O. lancifer there either. Our ecological niche model shows that the southeastern most corner of Oklahoma provides suitable environmental conditions for the species ( Figure 52 ). Generally, Orconectes lancifer can be found in swamps, oxbow lakes, and floodplains with mud or silt substrates. It can also inhabit large slow moving rivers. This species can survive drying conditions by finding refuge under wood debris and thick vegetation patches as it is a tertiary burrower (Pflieger, 1996; Taylor & Schuster, 2004).

Life history. As only two locations are known for O. lancifer (D. Arbour, personal communication), no life history information is available from Oklahoma. In Louisiana and Illinois (Page, 1985; Walls, 2009), form I males have been collected from August to November, which corresponds to the peak of breeding activities (Black, 1972). Form II males and females have been collected year round, but dominated collections from April to July. In Louisiana, females have been reported to carry the eggs throughout the winter, while young can be found in late spring into early summer (Walls, 2009). In Illinois, ovigerous females have been collected in September and October (Page, 1985).

Syntopic species. In Oklahoma, no syntopic crayfish species are known at this time.

Conservation status. AFS: Currently Stable; Heritage Rank: Widespread (G5); IUCN: Least Concern; ODWC: Not Listed.

Additional resources. Hobbs (1989); Taylor et al. (2004).

Figures

FIGURES 45 – 52. 45. Orconectes causeyi 46. Potential distribution of Orconectes causeyi 47. Orconectes deanae 48. Potential distribution of Orconectes deanae 49. Orconectes difficilis 50. Potential distribution of Orconectes difficilis 51. Orconectes lancifer 52. Potential distribution of Orconectes lancifer.