Clausiliidae Explained

Clausiliidae, also known by the common name door snails, is a taxonomic family of small, very elongate, mostly left-handed, air-breathing land snails, sinistral terrestrial pulmonate gastropod mollusks.[1]

With over 1700 recognized recent and fossil species,[2] this is among the most diverse families of terrestrial gastropods (cf. Orthalicidae), although the marine gastropod family Pyramidellidae is larger.

Most species of Clausiliidae have an anatomical structure known as a clausilium, which enables the snail to close off the aperture of the shell with a sliding "door".

Shell description

Almost all the species of snails in the family of door snails are left-handed, which is an uncommon feature in gastropod shells in general.

These snails have shells which are extremely high-spired, with numerous whorls.

The shells tend to be club-shaped, tapering at both ends to a rounded nub. The aperture usually has visible folds.

The clausilium

See main article: clausilium. Clausiliids are also very unusual among pulmonate gastropods in that most of them have a "door" or clausilium. The clausilium is not the same thing as an operculum, which does not exist at all in pulmonate gastropods.

The clausilium is a calcareous structure, tongue-shaped or spoon-shaped, which can close the aperture of the snail shell to protect the soft parts against predation by animals such as carnivorous beetle larvae. The narrow end of the clausilium slides in the grooves that are formed by the folds on the inside of the shell.

Anatomy

In this family, the number of haploid chromosomes lies between 21 and 30 (according to the values in this table).[3]

Taxonomy

The type genus is Clausilia Draparnaud, 1805.

The family Clausiliidae is classified within the informal group Sigmurethra, itself belonging to the clade Stylommatophora within the clade Eupulmonata (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).

2005 taxonomy

The taxonomy of the Gastropoda by Bouchet & Rocroi, 2005 recognizes subfamilies as follows:

subfamily Clausiliinae Gray, 1855

subfamily Alopiinae A. J. Wagner, 1913

subfamily † Constrictinae H. Nordsieck, 1981[4]

subfamily Garnieriinae C. Boettger, 1926

subfamily † Eualopiinae H. Nordsieck, 1978

subfamily Laminiferinae Wenz, 1923

subfamily Mentissoideinae Lindholm, 1924

subfamily Neniinae Wenz, 1923 - Neniastrinae H. B. Baker, 1930

subfamily Phaedusinae A. J. Wagner, 1922

subfamily Serrulininae Ehrmann, 1927

Genera

Genera include:

Clausiliinae

Tribe Acrotomini H. Nordsieck, 1979

tribe Baleini

Tribe Boettgeriini H. Nordsieck, 1979

tribe Clausiliini

Tribe † Emarginariini H. Nordsieck, 2007

Tribe Euxinellini Neubert, 2002

Tribe Filosini H. Nordsieck, 1979

tribe Gracillariini H. Nordsieck, 1979

Tribe Mentissoideini Lindholm, 1924

Tribe Olympicolini Neubert, 2002

Tribe Strigileuxinini H. Nordsieck, 1994

Tribe Strumosini H. Nordsieck, 1994

Alopiinae A. J. Wagner, 1913

Alopiinae[9]

tribe Alopiini

tribe Cochlodinini Lindholm, 1925 (1923)

tribe Delimini R. Brandt, 1956

tribe Medorini H. Nordsieck, 1997

Constrictinae

Fossil subfamily Constrictinae contains genera:

Eualopiinae

Fossil subfamily Eualopiinae contains genera:

Tribe † Eualopiini H. Nordsieck, 1978

Tribe † Rillyini † H. Nordsieck, 1985

Garnieriinae

Laminiferinae

Tribe Laminiferini Wenz, 1923

Tribe † Oospiroidesini H. Nordsieck, 2007

Tribe † Polloneriini H. Nordsieck, 2007

Mentissoideinae

synonym of the tribe Mentissoideini Lindholm, 1924 (superseded classification)

Neniinae Wenz, 1923

Tribe Neniini Wenz, 1923

Peruiniinae H. Nordsieck, 2005

Phaedusinae A. J. Wagner, 1922

Tribe † Disjunctariini H. Nordsieck, 2014

Tribe † Nordsieckiini H. Nordsieck, 2007

tribe Phaedusini A. J. Wagner, 1922

Tribe † Serrulellini H. Nordsieck, 2007

Tribe Serrulinini Ehrmann, 1927

Tribe Synprosphymini H. Nordsieck, 2007

Synonyms

Conservation

Although non-marine molluscs appear to be exceptionally vulnerable to extinction,[13] the IUCN Red list listed only 9 species[14] from this family.

Further reading

External links

Notes and References

  1. MolluscaBase eds. (2023). MolluscaBase. Clausiliidae L. Pfeiffer & J. E. Gray, 1855. Accessed through: World Register of Marine Species at: https://www.molluscabase.org/aphia.php?p=taxdetails&id=833936 on 2023-04-11
  2. MolluscaBase eds. (2023). MolluscaBase. Clausiliidae L. Pfeiffer & J. E. Gray, 1855. Accessed through: World Register of Marine Species at: https://www.molluscabase.org/aphia.php?p=taxdetails&id=833936 on 2023-04-11
  3. Barker G. M.: Gastropods on Land: Phylogeny, Diversity and Adaptive Morphology. in Barker G. M. (ed.): The biology of terrestrial molluscs. CABI Publishing, Oxon, UK, 2001, . 1-146, cited pages: 139 and 142.
  4. Nordsieck H. (1981). Archiv für Molluskenkunde 111(1-3): 101.
  5. Nordsieck H. (1978). Archiv für Molluskenkunde 109(1-3): 104.
  6. Nordsieck H. (1985). Heldia 1(3): 83.
  7. https://web.archive.org/web/20121012221948/http://www.faunaeur.org/full_results.php?id=422664 "Clausiliini"
  8. https://web.archive.org/web/20121012221948/http://www.faunaeur.org/full_results.php?id=422664 "Graciliaria"
  9. Uit de Weerd D. R. (2004). "Molecular phylogenetic history of eastern Mediterranean Alopiinae, a group of morphologically indeterminate land snails". Doctoral thesis, Leiden University, .
  10. Gittenberger E. & Uit de Weerd D. R. (2009). "Summarizing data on the Inchoatia taxa, including Inchoatia megdova bruggeni subspec. nov. (Gastropoda, Pulmonata, Clausiliidae)" Zoologische Mededelingen 83 http://www.zoologischemededelingen.nl/83/nr03/a08
  11. cf. Nordsieck H. (2006). "Species list of recent Clausiliidae".
  12. Maassen W. J. M. & Gittenberger E. (2007). "Three new clausiliid land snails from Tonkin, northern Vietnam (Gastropoda: Pulmonata: Clausiliidae)". Zoologische Mededelingen 81(1): http://www.zoologischemededelingen.nl/81/nr01/a10
  13. Lydeard . C. . Cowie R. . Ponder, W.F. . April 2004 . The global decline of nonmarine mollusks . . 54 . 4 . 321–330 . 10.1641/0006-3568(2004)054[0321:TGDONM]2.0.CO;2 . etal . dmy . free .
  14. IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2. . Downloaded on 5 March 2010.