Common spiral staircase
| Common spiral staircase | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Housing of Epitonium clathrus |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Epitonium clathrus | ||||||||||||
| ( Linnaeus , 1758) |
The common spiral staircase ( Epitonium clathrus , Syn .: Epitonium clathrum ) is a spiral staircase snail that is native to the North Sea and the Mediterranean . It feeds as predators of sessile cnidarians .
features
The right-hand winding , tower-shaped housing of the common spiral staircase, which can be up to 40 mm long and 12 mm wide, has 15 strongly convex passages with a circular cross-section, which are not connected by a seam, but by the union of the axial, keel-shaped ribs. The ribs are connected to those of the next gallery, but not to each other on the same gallery. The surface is smooth between the ribs. The case mouth is almost circular and has a slightly inflated rim. The inner lip is bent back at the base of the adjoining seven ribs. The white to light brown surface is often covered with spirally running bands of brown spots. The round, horny operculum has an indented core.
The slender antennae on the head are provided with eyes at their base. The foot has straight, double-edged front and middle pits on the sole.
Occurrence and distribution
Epitonium clathrus lives below the intertidal zone of sandy or muddy subsoil up to 70 m deep, but the snail can come up to the tidal area to lay eggs.
The snail is widespread from the Mediterranean to Norway and the Kattegat , on the British Isles , the German Bight and off Heligoland .
Life cycle
The spiral staircase snail is first a male and later a female. After internal fertilization, the female lays the eggs in long threads with pyramidal capsules at the lower edge of the intertidal zone. The Veliger larvae hatch after about two weeks and go through a longer phase than zooplankton .
nutrition
Epitonium clathrus eats sea anemones and hard corals (Scleractinia). The preferred prey include the wax Rose ( Anemonia sulcata ). Pieces are cut out of the hive with the pines.
ssp. mediterraneum
.jpg)
literature
- John D. Fish, Susan Fish: A Student's Guide to the Seashore . Cambridge University Press, Cambridge 2011. 540 pages. Epitonium clathrus (Linnaeus) , p. 230.
