Survey of pulmonate snails of central Minnesota .1. Lymnaeidae

Aquatic snails were collected at 148 sites from various wetland habitats in central Minnesota between May and September, 1988. Ten lymnaeid species were collected, including Lymnaea palustris, L. stagnalis, L. exilis, L. caperata, L. catascopium, L. megasoma, L. Fossaria modicella, L. (F.) parva, L. (F.) bulimoides, and L. (F.) dalli. These species were found at 30-, 18-, 15-, 12-, 11-, 7-, 20-, 9-, 1.4-, and 0.7% of the collection sites, respectively. Lymnaeids were found most frequently in still water of near neutral pH with a small particle size substrate. However, individual lymnaeid species showed great variability in habitat type selection. Lymnaea megasoma and L. exilis were found in slightly acidic water. Lymnaea catascopium was found in the deeper open water of lakes and slow moving rivers, while L. caperata and L. (Fossaria) spp. were found in temporary wetlands and mud flats. Wetland habitat reduction during the drought of 1987-1989 may have influenced distribution of the amphibious species. Those species recovered from shallow temporary wetlands in this study may have a wider distribution during periods of normal rainfall.