Physidae
Physidae | |
---|---|
A live individual of Physella acuta from the Mediterranean area | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Gastropoda |
Subclass: | Heterobranchia |
Infraclass: | Euthyneura |
Superorder: | Hygrophila |
Superfamily: | Lymnaeoidea |
Family: | Physidae Fitzinger, 1833[1] |
Type genus | |
Physa Draparnaud, 1801 | |
Diversity[2] | |
About 80 freshwater species |
Physidae,
Overview
These
These snails are common in the North Temperate to Arctic Zones and throughout the Americas, in readily accessible habitats such as ditches, ponds, lakes, small streams, and rivers. The family has been recognized since the 19th century, and yet there has been no classification in which relationships between genera are clarified, no agreement on what characters are primitive or advanced, and no consistent ranking. Scarcity of careful morphological studies is the principal cause. The differences in the group have led to the creation of more than 23 genera, four grades and four clades within the family. The two established subfamilies are divided into seven new tribes including 11 new genera.[5] Within this family, the shell is always sinistral, in other words it has left-handed coiling. Physidae has 23 genera, 17 occur in Pacific drainages of North and Central America, eight of these restricted to the region. Concentration of primitive genera along the Pacific coast from Mexico to Costa Rica conforms to previous observations that primitive pulmonate families are concentrated within, or along the continental margins of, the Pacific Ocean. An ancestral origin of Physidae along an ancient eastern Pacific coast is probable. From this region the several lineages have spread to north, south and east in the Americas, and through Siberia to Europe.
Ecology
These small snails are quite distinctive, because they have sinistral shells, which means that if the shell is held such that the spire is pointing up and the aperture is facing the observer, then the aperture is on the left-hand side. The shells of Physidae species have a long and large aperture, a pointed spire, and no operculum. The shells are thin and corneous, and rather transparent. Studies in 1982 indicate that they are most abundant in the New World. They have evidently found a shell morphology suitable for their life station, as he goes on to say "...the physids have undergone considerable diversification, much of which is not clearly exhibited in their shells. Many of the species, and genera, are not easy to identify on shell characters alone."
They have been used in studies of ecophenotypic plasticity, a so-called phenoplastic switch. Burt Vaughan of Washington State University indicates several studies in M. J. West-Eberhardt's recent compendium of research, "Developmental Plasticity & Evolution" (Oxford Press, 2003, pp. 307–362).
In 1921, the strong reaction of Physa to contact with leeches was first observed. Later studies have also been made. The observations are restricted to
Taxonomy
According to
- subfamily Physinae Fitzinger, 1833: Preputial gland present
- tribe Haitiini D.W. Taylor, 2003
- tribe Physini Fitzinger, 1833
- tribe Physellini D. W. Taylor, 2003
- subfamily Aplexinae Starobogatov, 1967: Preputial gland absent
- tribe Aplexini Starobogatov, 1967
- tribe Amecanautini D. W. Taylor, 2003
- tribe Austrinautini D. W. Taylor, 2003
- tribe Stenophysini D. W. Taylor, 2003
- Genera in the family Physidae include
- † Berellaia De Laubrière & Carez, 1881 †
- † Hannibalina Hanna & Gester, 1963 †
- † Prophysa Bandel, 1991
subfamily Aplexinae
Aplexini
- Amuraplexa Starobotatov, Prozorova & Zatravkin, 1989
- Aplexa Fleming, 1820 - aplexa, type genus of the subfamily Aplexinae[3]
- Paraplexa Starobogatov, 1989
- Sibirenauta Starobogatov & Streletzkaja, 1967
Amecanautini
- Amecanauta D. W. Taylor, 2003 - type genus of the tribe Amecanautini[3]
- Mayabina Taylor, 2003[7]
- Mexinauta Taylor, 2003[7]
- Tropinauta Taylor, 2003[7]
Austrinautini
- Austrinauta D. W. Taylor, 2003 - type genus of the tribe Austrinautini[3]
- Caribnauta Taylor, 2003[7]
Stenophysini
- Afrophysa Starobogatov, 1967
- Stenophysa von Martens, 1898 - type genus of the tribe Stenophysini[3]
subfamily Physinae
Haitiini
Physini
- Beringophysa Starobogatov & Budnikova, 1976
- Laurentiphysa Taylor, 2003[7]
- Physa Draparnaud, 1801 - type genus of the family Physidae[3]
Physellini
- Archiphysa Taylor, 2003[7]
- Chiapaphysa Taylor, 2003[7]
- Petrophysa Pilsbry, 1926 [1]
- Physella Haldemann, 1843 - type genus of the tribe Physellini[3]
- Ultraphysella Taylor, 2003[7]
- Utahphysa Taylor, 2003[7]
- Genera brought into synonymy
- Aplecta Herrmannsen, 1846: synonym of Aplexa J. Fleming, 1820 (invalid: an incorrect subsequent spelling of Aplexa)
- Archiphysa D. W. Taylor, 2003: synonym of Physella Haldeman, 1842 (a junior synonym)
- Costatella Dall, 1870: synonym of Physella (Costatella) Dall, 1870 represented as Physella Haldeman, 1842
- Haitia Clench & Aguayo, 1932: synonym of Physella (Acutiana) Fagot, 1883 represented as Physella Haldeman, 1842
- Laurentiphysa Taylor, 2003: synonym of Physa Draparnaud, 1801 (a junior synonym)
- Rivicola Fitzinger, 1833: synonym of Physa Draparnaud, 1801 (Invalid: junior objective synonym of Physa, with the same type species)
Aquarium use
Physid snails are often introduced to an aquarium accidentally as eggs on aquatic plants. These snails are sometimes viewed as pests in aquarium tanks with fish, because the snails create waste, reproduce very often, and are very hard to remove completely. However, some aquarium owners deliberately chose to add these freshwater pond snails to their tank because the snails will eat uneaten fish food, algae and waste, as well as unwanted fish carcasses.[citation needed]
References
- ^ Fitzinger L. (1833). Beiträge zur Landeskunde Oesterreich's unter der Enns, Bd. 3: 110.
- .
- ^ ISSN 0076-2997.
- ^ MolluscaBase eds. (2021). MolluscaBase. Physidae Fitzinger, 1833. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=160452 on 2021-06-26
- ^ a b "Archived copy" (PDF). Archived from the original (PDF) on 2011-06-29. Retrieved 2010-04-08.
{{cite web}}
: CS1 maint: archived copy as title (link) - ^ "Physidae".
- ^ a b c d e f g h i j Taylor D. W. (2003). "Introduction to Physidae (Gastropoda: Hygrophila). Biology, classification, morphology". Revista de Biología Tropical 51(Suppl. 1): 1-299. (1-195) 197-263, 265-287).
- Haas, F. (1952). On the mollusk fauna of the landlocked waters of Bermuda. Fieldiana: Zoology, 34(8): 101-105
- Janus, Horst, 1965. The young specialist looks at land and freshwater molluscs, Burke, London
- 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
Further reading
- Wethington A. R. & Lydeard C. (2007). "A molecular phylogeny of Physidae (Gastropoda: Basommatophora) based on mitochondrial DNA sequences". .