The tulotoma snail was first described in 1834 and is native to the Alabama-Coosa River system and tributaries in the US state of Alabama, inhabiting the underside of large rocks in fast-flowing water. The species is unique in that it gives birth to live young, rather than eggs or larvae as most other snails do. It is considered large in comparison with other freshwater snails – its shell, ornamented with knobs and spirals, grows up to 25mm in height.
T. magnifica was once found in great numbers but by the 1950s it had all but disappeared from the Alabama River and only small, fragmented populations existed in just three creeks. The major contributing factor to the species’ decline was the construction of six dams on the Alabama and Coosa Rivers between 1914-1966, effectively draining 90 percent of the snail’s habitat in a river system that had a diversity of freshwater fauna as rich as any in the world.
The US Fish and Wildlife Service (USFWS) protected the snail in 1991 by listing it as an endangered species, which has led to a strong recovery. The Alabama Power Company, advised by USFWS, began to time its water release schedules to coincide with the species’ reproductive cycle, which also improved the habitat by increasing oxygen levels. Existing populations flourished and six further populations of the snail were discovered. The USFWS improved the species status from endangered to threatened in 2010.