ETWP; Determination of Endangered Status for the Tumbling Creek Cavesnail

We, the Fish and Wildlife Service (Service), determine the Tumbling Creek cavesnail (Antrobia culveri) to be an endangered species under the Endangered Species Act of 1973, as amended (Act). This species is known to occur in one cave in Missouri. The distribution of this species in Tumbling Creek has decreased by 90 percent since 1974. Although cavesnail numbers fluctuated seasonally and annually between 1996 and 2000, the species was not found in the monitored section of the cave stream during six surveys in 2001 and two surveys in 2002. Small numbers of individuals continue to exist in other portions of the cave stream. Because the sudden population decline demonstrates a significant and imminent risk to the well-being of the Tumbling Creek cavesnail, we find that listing this species is necessary to provide Federal protection pursuant to the Act.