Comparative conservation ecology of pleurocerid and pulmonate gastropods of the United States

To understand better the conservation status of freshwater pleurocerid gastropods in the southeastern United States, we contrasted their distribution and biology with pulmonate snails, a group far less imperiled. With 157 taxa in North America, the Pleuroceridae have a similar species richness to all pulmonate families combined (153 taxa). The Pleuroceridae has more recently extinct species (38) and 66% of the remaining taxa are considered imperiled (G Rank ≤2). Pleurocerid species richness is greatest in the Alabama and Tennessee River basins in the southeastern United States, with only 25 species outside the southeastern United States. We argue that the endemic nature of their distributions, limited dispersal, and poor abilities to colonize heighten chances of extinction for pleurocerids in comparison to pulmonates. We also outline our approach to conservation, which involves delineating appropriate habitat parameters for successful re-introductions using artificial propagation. We call for a national conservation strategy for pleurocerids, emphasizing threats to lotic pleurocerids and how management agencies can surmount them, similar to the strategy already developed for unionid bivalves