The Freshwater Gastropods of North America Project is a long-term, collaborative effort to survey the entire gastropod fauna inhabiting every river, lake, pond and stream in the continental United States and Canada. Born in the summer of 1998 at the World Congress of Malacology in Washington, the effort has covered all or part of 17 eastern states to date, extending from New York to Mississippi. Volume 1 (2019) in this series analyzed the results of a scientific survey of the freshwater gastropod fauna of the Atlantic drainages from Georgia through Pennsylvania, and Volume 5 (2023) extended our coverage through the Ohio, Cumberland and Tennessee drainages of the Midwest and South.
The first 13 essays collected here in Volume 7 complement and extend those published in Volume 4, focusing on biological invasion, the viviparids, and the ampullariids. The second set of 23 essays extend themes initially developed in Volume 2 (Pulmonates), with four essays on lymnaeids, five essays on physids, twelve on planorbids, and one on ancylid limpets. All are essential background to understand the context and rationale for the methodological and taxonomic approaches advanced in Volumes 1 and 5.