Physa
| Physa | |
|---|---|
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| Shells of Physa fontinalis | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| (unranked): | clade Heterobranchia clade Euthyneura clade Panpulmonata clade Hygrophila |
| Superfamily: | Planorboidea |
| Family: | Physidae |
| Subfamily: | Physinae |
| Tribe: | Physini |
| Genus: | Physa Draparnaud, 1801[1] |
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 detritus.
Contents |
[edit] Anatomy
Members of the freshwater pulmonate family Physidae possess a complex of muscles that is unique amongst gastropods. This complex was given the name “physid musculature”. The physid musculature has two main components, the physid muscle sensu stricto and the fan muscle. The physid musculature is responsible for a unique ability of physids to rapidly flick their shells from side to side — a reaction that frequently enables them to escape predation.
[edit] Shell description
These small snails, like all the species in the family Planorbidae, 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.
[edit] Species
Species in the genus include:
- Physa ancillaria (Say, 1825) - Pumpkin Physa[2]
- Physa carolinae Johns Island, South Carolina 2010 by Amy Wethington in ditch, then confirmed at the University of Alabama[3]
- Physa concolor
- Physa fontinalis - Fountain bladder snail - type species
- Physa hordacea (I. Lea, 1864)
- Physa jennessi Dall, 1919
- Physa lordi (Baird, 1863)
- Physa marmorata Guilding, 1828[4] - synonyms: Physa mosambiquensis Clessin, 1886 and Physa waterloti[4]
- 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. 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 was pending in 2005.[5]
Synonyms:
- Physa acuta Draparnaud, 1805, Physa heterostropha (Say, 1817) and Physa integra (Haldeman, 1841) are a synonyms for Physella acuta (Draparnaud, 1805)
- Physa columbiana (Hemphill, 1890) is a synonym for Physella columbiana (Hemphill, 1890)
- Physa gyrina (Say, 1821) is a synonym for Physella gyrina (Say, 1821)
[edit] References
- ^ Draparnaud J. P. R. (1801). Tableau des mollusques terrestres et fluviatiles de la France. - pp. [1-2], 1-116. Montpellier, Paris. (Renaud; Bossange, Masson & Besson).
- ^ "Physella". NatureServe Explorer, accessed 9 April 2010.
- ^ http://www.postandcourier.com/news/2010/apr/03/snail-sleuthsc-of-c-researchers-find-lowcountry/
- ^ a b Appleton C. C. & Dana P. (2005). "Re-examination of Physa mosambiquensis Clessin, 1886 and its relationship with other Aplexinae (Pulmonata: Physidae) reported from Africa". African Invertebrates 46: 71-83. abstract
- ^ COSEWIC. 2005. Canadian Species at Risk. Committee on the Status of Endangered Wildlife in Canada. 64 pp., page 13.
- Janus, Horst, 1965. ‘’The young specialist looks at land and freshwater molluscs’’, Burke, London
[edit] External links
- http://www.animalbase.uni-goettingen.de/zooweb/servlet/AnimalBase/list/species?taxongenus=301
- Dillon R. T., Wethington A. R. & Lydeard C. (2011). "The evolution of reproductive isolation in a simultaneous hermaphrodite, the freshwater snail Physa". BMC Evolutionary Biology 11: 144. doi:10.1186/1471-2148-11-144.
