Baseline monitoring and molecular characterization of the state endangered Enigmatic Cavesnail, Fontigens antroecetes (Hubrict 1940)

Like most endangered cave invertebrates, the first thing that we learn in attempting to recover the species is that we know virtually nothing about it. This is the case for Fontigens antroecetes–currently we have only information on the distribution and morphology of the species. Population size, microhabitat preferences, reproductive rates, or connectivity among populations (likelihood of gene exchange)are unknown. With continuing rapid growth in the greater St. Louis metropolitan area, which extends deep into Monroe and St. Clair counties, Illinois, there are ever increasing threats to the shallow groundwater in Illinois’ sinkhole plain. High levels of fecal coliforms and other contaminants have already been well documented in Illinois caves (Taylor et al. 2000c). In addition, the population of the Illinois Cave Amphipod (Gammarus acherondytes, an aquatic cave species listed as Endangered at the federal level) in Stemler Cave is thought to have been extirpated. As this is the sole Illinois locality for the Enigmatic Cavesnail, there is reason for grave concern for the long term persistence of this snail population. Given the above facts, we felt it was important to obtain baseline data on the Illinois population of F. antroecetes, including abundance, evaluation of microhabitat preferences, and characterization of genetic diversity.