Status and Distribution of the Cave-Obligate Land Snails in the Appalachians and Interior Low Plateau of the Eastern United States

Abstract

Cave-obligate (troglobiotic) land snails are among the most understudied taxa inhabiting cave systems because of their small size and cryptic nature. Other than locality records and general descriptions of species' morphology, information regarding most cave snail taxa is minimal. Given the importance of land snails as indicator species and as important drivers of ecosystem processes, this lack of knowledge on cave-obligate taxa impedes conservation management of subterranean snails and subterranean ecosystems in general. As a first step, we compiled and georeferenced all available distributional records for troglobiotic snail species within two major karst regions in the United States: The Interior Low Plateau (ILP) and Appalachians. We identified 16 new localities among these species from caves in Alabama, Tennessee, and Georgia from 2012 to 2016, yielding 8 new occurrences of two species in the ILP and 8 new occurrences of three species in the Appalachians. In total, we report 143 occurrences for five species in 124 caves, representing the most comprehensive dataset on the distribution of caveobligate snails in the eastern United States to date. We also provide the first IUCN Red List conservation assessments for all five troglobiotic taxa and reexamine NatureServe conservation ranks. Our assessments indicate that three of the five species are considered at an elevated risk of extinction. Given these ranks and the threats identified to each species, we offer recommendations concerning the conservation and management of these cave snails and outline future areas of research for these taxa.