The shells of species in the genus "Physa" are left-handed or sinistral. Among the genera found in its deposits are "Physa", "Planorbella", "Pyganodon" and "Succinea". In "Haitia acute", the avoidance reaction was much less pronounced than in "Physa fontinalis". Common names include European physa, tadpole snail, bladder snail, and acute bladder snail. "Physa fontinalis" is a Least Concern species. Native freshwater snails such as "Physa cubensis" have been adversely affected by introduced species. The Snake River physa is rare, with fewer than 50 total individuals having been collected. Other mollusks found in the vicinity include "Physa mexicana", "Lymnaea modicella", and "Pisidium casertanum".