Clausilium

The anatomical features of the inner shell of the Alinda biplicata snail , shown in the drawing using a partially open shell. The spoon-shaped end of the Clausilium is marked with the number 5. Please click on the picture for an explanation of the other digits

A clausilium is a housing closure, as with the family of the door snails occurs (Clausiliidae).

Morphology and function

The clausilium consists of a tongue-shaped, spoon-shaped or spatula-shaped plate of lime, connected with an elastic band, which slides sideways into the casing when the snail crawls out of its casing. When the mouth of the housing has been closed with the wide and flat end of the clausilium, the snail finds a certain protection from predators inside.

The narrow end of the clausilium is located in a fold in the interior of the bowl, which is spiraled around the columella . Due to the length of this pit and the muscle with which the snail moves the clausilium, it is possible for it to completely withdraw the clausilium into the shell.

In contrast to the operculum , the clausilium of door snails belongs to the shell and is firmly attached to it, but not attached to the soft body of the animal, so that clausilia can also be found on empty shells. Neither the clausilium is the only temporarily formed in the winter cover ( Epiphragma ) of the snails equate.

literature

• Iľja Michajlovič Licharev: Klauziliidy (Clausiliidae). Fauna SSSR. Molljuski. Vol. 3, Fasc. 4th, Izd. Akad. Nauk SSR, Moskva 1962, OCLC 716796021 .

Web links

• The shell of the snail

See also

• Operculum
• Epiphragma