Physa

Taxobox
name = "Physa"

---

image_caption = shells of "Physa fontinalis"
status =
regnum = Animalia
phylum = Mollusca
classis = Gastropoda
subclassis = Orthogastropoda
superordo = Heterobranchia
ordo = Basommatophora
superfamilia = Lymnaeoidea
familia = Physidae
genus = "Physa"
genus_authority = Draparnaud, 1801
species =
binomial =
binomial_authority =

"Physa" is a genus of small, left-handed or sinistral, air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the family Physidae.

These snails eat algae, diatoms and other detritus.

hell description

These small snails are quite distinctive, because they have shells that are sinistral, which means that if you hold the shell such that the spire is pointing up, then the aperture is on the left-hand side.

The shells of "Physa" species have a long and large aperture, a pointed spire, and no operculum. The shells are thin and corneous and rather transparent.

pecies

Species in the genus include

* "Physa columbiana" (Hemphill, 1890)
* "Physa concolor"
* "Physa fontinalis" - Fountain bladder snail
* "Physa gyrina" (Say, 1821)
* "Physa heterostropha" (Say, 1817)
* "Physa hordacea" (I. Lea, 1864)
* "Physa integra" (Haldeman, 1841)
* "Physa jennessi" Dall, 1919
* "Physa lordi" (Baird, 1863)
* "Physa marmorata" Guilding, 1828
* "Physa megalochlamys" Taylor, 1988
* "Physa natricina" Taylor, 1988
* "Physa nuttalli"
* "Physa propingua" (Tryon, 1865)
* "Physa pumilia" Conrad, 1834
* "Physa siberica" Westerlund, 1876
* "Physa skinneri" Taylor, 1954
* "Physa vernalis" Taylor et Jokinen, 1984

* "Physa" sp., Lake Winnipeg Physa, lives in Manitoba in Canada and it was classified as endangered by COSEWIC. COSEWIC recommendation has been forwarded to the Minister of the Environment of Canada and a decision for listing at the List of Wildlife Species at Risk of the Canadian Species at Risk Act is pending. [COSEWIC. 2005. [http://www.sararegistry.gc.ca/virtual_sara/files/species/clwsa%5F0505%5Fe%2Epdf Canadian Species at Risk] . Committee on the Status of Endangered Wildlife in Canada. 64 pp., page 13.]

References

* Janus, Horst, 1965. ‘’The young specialist looks at land and freshwater molluscs’’, Burke, London