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We documented the currently known distribution of the Asian snail Bellamya (=Cipangopaludina) chinensis in Minnesota, along with another viviparid snail, Viviparus georgianus, a North American native whose range has expanded. We also recorded the first known occurrence of Bellamya japonica in Wisconsin. Bellamya chinensis and V. georgianus occurred predominately in lakes within the Minneapolis/St. Paul metropolitan area and the lakes region of northcentral Minnesota. Both species are now established in the three major watersheds that drain Minnesota. We collected Bellamya japonica at six sites in the Namekagon River, part of St. Croix River system in Wisconsin. [ABSTRACT FROM AUTHOR]

The ebony shell (Fusconaia ebena) is extirpated from much of the upper Mississippi River drainage. Nonetheless, in the past 25 years 94 live individuals were collected at 23 sites in the upper Mississippi River between Lock and Dam 6 and 26, three sites in the lower St. Croix River, and one site in the lower Wisconsin River. Most of the recent records were from the lower St. Croix River and the lower reaches of the upper Mississippi River. These data support the hypothesis thatLock and Dam 19 inhibits F. ebena from recolonizing the Mississippi River above the dam by preventing its migratory host fish, skipjack herring (Alosa cltrysochloris),from moving upstream. Populations aboveLock and Dam 19 are probably pre-lock and dam remnants that have persisted for over a half century and are at risk of extirpation. Conservation efforts should focus on artificial propagation and dam modifications that allow the passage of migratory fishes. [ABSTRACT FROM AUTHOR]