Clausiliidae

From Wikipedia, the free encyclopedia

Clausiliidae

Cochlodina laminata

Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Order:	Pulmonata
Family:	Clausiliidae J. E. Gray, 1855

Clausiliidae, common name door snails, are a taxonomic family of small, very elongate, mostly left-handed, air-breathing land snails, sinistral terrestrial pulmonate gastropod mollusks.

With about 1,300 species recent and fossil, this may arguably be one of the largest families of gastropods.

1 Description
- 1.1 The clausilium
2 Taxonomy
3 References
4 Recommended literature
5 External links

[edit] Description

Megalophaedusa martensi is the largest species of the family Clausiliidae in the world. The individual in the photo has a shell of 45.5 mm long and weighs 3.2 g live including the soft parts.

Wikimedia Commons has media related to:

Clausiliidae

Almost all the species of snails in the family of door snails are left-handed, which is interesting because it is an uncommon feature in gastropods in general.

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

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

[edit] The clausilium

The clausilium of Clausilia dubia

Clausiliids are also very unusual among pulmonate gastropods in that they all have a "door" or clausilium. The clausilium is not the same thing as an operculum, which does not exist at all in pulmonate gastropods. Nonetheless 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. One end of the clausilium slides in the grooves that are formed by the folds on the inside of the shell.