| Abstract |
The Lee County cave isopod, Lirceus usdagalun, is a subterranean freshwater crustacean belonging to the family Asellidae. The family is represented in North America by several ganera, including Caecidotea and Lirceus. While Caecidotea is known to occur in both surface water and underground habitats, Lirceus is almost always found in surface water habitats, such as springs, seeps, and small streams. Unlike most other species in this genus, Lirceus usdagalun is a troglobite, an obligate cave-dwelling organism. This isopod is endemic to southwestern Virginia, where it has been documented from only two cave systems and two springs (both presumably associated with undiscovered cave systems) in Lee County. The Lee County cave isopod was federally listed as endangered in No9vember of 1992 (U.S. Fish and Wildlife Service 1992). This status was determined because one of the two populations known prior to listing was extirpated, leaving a single population. In addition, the Lee County cave isopod has an extremely limited range, increasing its susceptibility to a single incident of groundwater pollution, which could pose serious threats to the survival of the species. |
