Viviparidae


Viviparidae, commonly called river snails or mystery snails, are a family of freshwater snails with gills and a protective lid. Recent studies show that their family tree is more complex than expected, with genetic evidence suggesting some species don't fit neatly into traditional groups. These snails are found in lakes and rivers across Europe, Asia, and parts of North America, where some, like Cipangopaludina japonica, have spread as invasive species thanks to their ability to adapt.

Distribution

This family occurs nearly worldwide in temperate and tropical regions, with the exception that they are absent from South America.
There are two genera of Viviparidae in Africa: Bellamya and Neothauma.
The oldest known vivparid is Viviparus langtonensis from the Middle Jurassic of England. The oldest records from the Southern Hemisphere is from the Late Jurassic Talbragar fossil beds of Australia.
Viviparidae snails live in freshwater spots like rivers and lakes across Europe, Asia, and parts of North America. Recent surveys show they're spread out widely in places like Russia and China, adapting well to different environments.You won't find them in South America, though. Some, like Cipangopaludina japonica, have even popped up in new areas, such as North America, because they're good at moving in and taking over

Taxonomy and phylogeny

The family Viviparidae contains 3 subfamilies :
  • Viviparinae Gray, 1847 - synonyms: Paludinidae Fitzinger, 1833 ; Kosoviinae Atanackovic, 1859
  • Bellamyinae Rohrbach, 1937 - synonym: Amuropaludinidae Starobogatov, Prozorova, Bogatov & Sayenko, 2004
  • Lioplacinae Gill, 1863 - synonym: Campelomatinae Thiele, 1929
Scientists used to group Viviparidae snails based on how they look, but new research using DNA has shaken things up. Studies of snail genes, like those from species such as Viviparus chui and Cipangopaludina chinensis, show that some don't belong where we thought they did, making the family tree more complicated than expected.In Japan, DNA tests on snails like Sinotaia quadrata histrica also found differences between what their genes say and how they've been classified before. This means figuring out how these snails are related is still a work in progress.

Morphology and evolution

Viviparidae snails have shells that can look different depending on where they live, and early studies suggest their surroundings help shape them over time. A scientist named Annandale found that things like water conditions might change how their shells grow, making them better suited to freshwater life.Today, research on snails like Cipangopaludina japonicashows their shells and bodies are built in ways that help them thrive, even in new places where they've spread. These snails can live anywhere from 3 to 11 years, depending on their environment.

Genera

Genera within the family Viviparidae include:
  • subfamily Viviparinae Gray, 1847
  • * Galizgia Mikhaylovskiy, 1903
  • * † Kosovia Atanacković, 1959
  • * Rivularia Heude, 1890
  • * Trochopaludina Starobogatov, 1985
  • * Tulotoma Haldeman, 1840
  • * Viviparus Montfort, 1810 - type genus
  • subfamily Bellamyinae Rohrbach, 1937
  • * Amuropaludina Moskvicheva, 1979
  • * Angulyagra Rao, 1931
  • * Anulotaia Brandt, 1968
  • * Anularya Zhang & Chen, 2015
  • * † Apameaus Sivan, Heller & van Damme, 2006 This Pliocene-Pleistocene genus contains only one species Apameaus apameae Sivan, Heller & van Damme, 2006
  • * Bellamya Jousseame, 1886 - type genus of the subfamily
  • * Boganmargarya Thach, 2018
  • * Cipangopaludina Hannibal, 1912
  • * Eyriesia P. Fischer, 1885
  • * Filopaludina Habe, 1964
  • * Heterogen Annandale, 1921 - with the only species Heterogen longispira
  • * Idiopoma Pilsbry, 1901
  • * Larina Adams, 1851
  • * Margarya Nevill, 1877
  • * Mekongia Crosse & Fischer, 1876
  • * Neclarina Iredale, 1943
  • * Notopala Cotton, 1935
  • * Sinotaia Haas, 1939
  • * Taia Annandale, 1918
  • * † Temnotaia Annandale, 1919
  • * Tchangmargarya He, 2013
  • * Torotaia Haas, 1939
  • * Trochotaia Brandt, 1974
  • subfamily Lioplacinae Gill, 1863
  • * Campeloma Rafinesque, 1819
  • * Lioplax Troschel, 1856
  • subfamily?
  • * † Albianopalin Hamilton-Bruce, Smith & Gowlett-Holmes, 2002 - from Albian, New South Wales
  • * Neothauma E. A. Smith, 1880
  • * Siamopaludina Brandt, 1968
;Genera brought into synonymy
  • Centrapala Cotton, 1935: synonym of Larina A. Adams, 1855
  • Contectiana Bourguignat, 1880: synonym of Viviparus Montfort, 1810
  • Eularina Iredale, 1943: synonym of Larina A. Adams, 1855
  • subfamily † Kosoviinae Atanacković, 1959: synonym of Viviparidae Gray, 1847
  • Lecythoconcha Annandale, 1920: synonym of Cipangopaludina Hannibal, 1912
  • Metohia Popović, 1964 :
  • Notopalena Iredale, 1943: synonym of Notopala Cotton, 1935
  • Paludina Férussac, 1812: synonym of Viviparus Montfort, 1810
  • Siamopaludina Brandt, 1968 : synonym of Filopaludina Brandt, 1968 represented as Filopaludina Habe, 1964
  • Vivipara : synonym of Viviparus Montfort, 1810

    Lifecycle

Viviparidare are viviparous: they give birth to live offspring instead of laying eggs. First, internal fertilization occurs, and from the on embryos continue to develop within the female's brood pouch. Here, they are nourished until they are matured. Once matured, the offsprings are released into the water as miniature versions of the adults. This method has shown to increase their chances of survival in freshwater environments. Life spans have been reported from 3 to 11 years in various species of Viviparidae, depending on environmental conditions and species type.

Fossil record

Viviparidae snails have been around for a long time, and their fossils, like Viviparus langtonensis, show they've lived in freshwater for millions of years. Recent DNA studies back this up, hinting at how these snails split into different types way back in history. These old clues help us understand where they came from and how they've changed.