Physa Heterostropha

''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).

Etymology

The etymology of the name ''Physella'' is obscure but could be ultimately from a Greek root. "Physella" (as a place name) is recorded in Giovanni Gemisto's printed edition of Pliny's encyclopedia, perhaps lifted from Ermolao Barbaro's ''Castigationes Plinianae'' where it is recorded as ''Physcella''. The French naturalist Jacques Draparnaud was the first to describe a species of the genus ''Physella'' and coined the name.

Shell description

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.

Distribution

It was once thought that the indigenous distribution of ''Physella acuta'' is Mediterranean.Glöer, P. 2002 ''Die Süßwassergastropoden Nord- und Mitteleuropas''. Die Tierwelt Deutschlands, ConchBooks, Hackenheim, 326 pp., , page 238-239. However, when ''Physella heterostropha'' is considered to be a synonym, then the indigenous distribution of the species includes North America.

''Physella acuta'' is a common species which is common in all of North America and Europe including the United Kingdom. The species seems to have first spread through the Mediterranean regions and then more slowly into Northern Europe. This species has been introduced into New Zealand and is widespread throughout both islands in ponds, lakes, and running water

In the United Kingdom

Within the United Kingdom, ''P. acuta'' is considered to be an invasive species. The "European physa" or "common bladder snail", as it is commonly known in England, is a prolific species that has undergone naturalisation. The European physa has been observed on several great Rivers, streams and tributaries within England, Wales, Scotland and Northern Ireland including the River Severn and the River Thames. The ecological impact of this invasive species to the native floral and faunal species of the United Kingdom was assessed by the United Kingdom Technical Advisory Group (UKTAG) as "Unknown" under the Water Framework Directive guidelines for Alien species.

In Europe

This species is found in:
* Belgium
* Serbia (it is especially abundant in the Drina river)
* Croatia
* Italy
* Czech Republic Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. (2010). "Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. nnotated list of mollusc species recorded outdoors in the Czech and Slovak Republics. ''Malacologica Bohemoslovaca'', Suppl. 1: 1–37
PDF
– not evaluated (NE)
* Slovakia
* Germany
* Netherlands
* Pripyat River since 1983 and in Neman River basin in Belarus since 2007Vitaliy Semenchenko, Tatiana Laenko & Vladimir Razlutskij. 2008
''A new record of the North American gastropod Physella acuta (Draparnaud 1805) from the Neman River Basin, Belarus''
Aquatic Invasions (2008) Volume 3, Issue 3: 359–360.
* Denmark
* and others

The distribution also includes Mediterranean regions and Africa.

In the Americas

The distribution includes the United States: Maryland, New Jersey, Tennessee, and Virginia.Amy Benson. 2007. ''Physella acuta''. USGS Nonindigenous Aquatic Species Database, Gainesville, FL. https://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=1025 Revision Date: 4/22/2004
* Cuba – native, also with ''Tarebia granifera'' it is the most common freshwater snail in CubaVázquez A. A. & Perera S. (2010). "Endemic Freshwater molluscs of Cuba and their conservation status". ''Tropical Conservation Science'' 3(2): 190–199
HTMPDF

*Chile invasive

Ecology

Habitat

This species lives in freshwater rivers, streams, lakes, ponds, and swamps.

''Physella acuta'' is frequently found in anthropogenic reservoirs, occurring in warm water discharges from power stations and in some rivers, but very rarely and not numerously in clay pit ponds. It can survive well under temporary harsh conditions (extreme temperature and water pollution), as long as they are short-lived.

Feeding habits

These snails eat dead plant and animal matter and various other detritus.

Because ''Physella acuta'' forages mainly on epiphytic vegetation and on the macrophytes, whereas other gastropods (''Planorbis planorbis'', ''Radix ovata'') exploit the algal cover or phytobentos on the bottom, competition between ''Physella acuta'' and other gastropods appears to be minimal.

Interspecific relationship

This species successfully co-exists with other alien gastropods: for example with ''Potamopyrgus antipodarum'' in many streams, lakes and ponds in New Zealand and with ''Lithoglyphus naticoides'' in the Danube River.
Within the United Kingdom, this species has also been to observed to coexists with Jenkins' Spire-Snail (''Potamopyrgus antipodarum'') in many aquatic habitats. The presence of the European physa may encourage proliferation of invasive non-native macrophytes such as Nuttall's waterweed (''Elodea nuttallii'')

Predators

The bladder snail is a frequent prey of many snail-eating predators, such as
*Anomalochromis
*Badis badis
*Carinotetraodon travancoricus
* Puntius titteya
*Ambastaia sidthimunki
*Chromobotia macracanthus
*Clea helena
*Sternotherus carinatus

Reproduction

''P. acuta'' is a self-compatible hermaphrodite. In natural populations, ''P. acuta'' preferentially reproduces by outcrossing.Noël E, Chemtob Y, Janicke T, Sarda V, Pélissié B, Jarne P, David P. Reduced mate availability leads to evolution of self-fertilization and purging of inbreeding depression in a hermaphrodite. Evolution. 2016 Mar;70(3):625-40. doi: 10.1111/evo.12886. Epub 2016 Mar 9. PMID: 26899922 When individuals from such populations self-fertilize they show a high degree of inbreeding depression. However, in exprerimentally constrained lines (where mates were often unavailable), after about 20 generations of self-fertilization, most of the inbreeding depression was purged.

References

This article incorporates CC-BY-2.0 text (but not under GFDL) from reference.

Further reading

* Naranjo-García E. & Appleton C. C. (2009). "The architecture of the physid musculature of ''Physa acuta'' Draparnaud, 1805 (Gastropoda: Physidae)". ''African Invertebrates'' 50(1): 1-11
Abstract

External links

''Physa acuta''
at AnimalBase taxonomy,short description, distribution, biology,status (threats), images
* https://web.archive.org/web/20071007012447/http://www.aquarium-kosmos.de/inhalt/50/blasenschnecken-physella-acuta
{{Taxonbar, from=Q1694040

Physidae
Gastropods described in 1805