Physella acuta

Physella acuta is a species of small, left-handed or sinistral, air-breathing freshwater snail, an aquatic gastropod mollusk in the family Physidae. Common names include European physa, tadpole snail, bladder snail, and acute bladder snail. In addition, Physa acuta, Physa heterostropha (Say, 1817) and Physa integra (Haldeman, 1841) are synonyms of Physella acuta (Draparnaud, 1805). Snails in the family Physidae have shells that are sinistral, which means that if the shell is held with the aperture facing the observer and the spire pointing up, then the aperture is on the left-hand side. The shells of Physella species have a long and large aperture, a pointed spire, and no operculum. The shells are thin and corneous and rather transparent. It was once thought that the indigenous distribution of Physella acuta is Mediterranean. However, when Physella heterostropha is considered to be a synonym, then the indigenous distribution of the species is North American. Physella acuta is a common species which is common in all of North America and Europe. The species seems to have first spread through the Mediterranean regions and then more slowly into Northern Europe.