Collected in Turn One, and Other Essays

What is the place of freshwater snails in modern culture, if any? Does their alleged rarity and undeniable strangeness elicit conservation concern in small circles of the environmentally conscious? Might even smaller circles of professionals in tropical medicine and health worry about their potential to host parasitic diseases? And aren't some freshwater snails invasive? Or maybe they're just cute pets?

Collected here in Volume 7 of the FWGNA series are 36 essays, originally published in the genre-defining artistic universe known as the FWGNA Blog 2018 - 2023, exploring freshwater gastropod biology in the modern milieu. Our focus is on the larger prosobranchs – the viviparids and the ampullariid "mystery snails" – as well as on the familiar pulmonate snails of the hobbyist aquarium and the lab bench. Reproductive allocation and the species concept, especially as applied to asexually-reproducing populations, emerge as primary themes, together with the omnipresent phenomenon of phenotypic plasticity. And along the way we'll check in with Gary, a pet mystery snail, who doesn't smell so good.

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.

Dr. Robert T. Dillon, Jr. is America's foremost authority on freshwater gastropods. From 1983 until his retirement in 2016 he was Professor of Biology at the College of Charleston in South Carolina. He is the author of The Ecology of Freshwater Molluscs (Cambridge University Press, 2000) and over 60 scientific papers on the genetics, evolution, and ecology of snails. A former president of the American Malacological Society, Dr. Dillon contributed the freshwater gastropod chapter to the popular 2006 AMS publication, The Mollusks: A Guide to their Study, Collection and Preservation. In 1998 he founded the Freshwater Gastropods of North America Project, authoring or coauthoring an extensive website, a popular blog, and seven hardcopy volumes to date.