Epitonium clathrum

Housing of Epitonium clathrus

The common spiral staircase ( clathrus Epitonium, Syn Epitonium clathrum ) is a spiral staircase snail that is native to the North Sea and the Mediterranean. They feed as predators of sessile cnidarians.

Features

The right-handed, tower -shaped enclosure of the commons spiral staircase, which can be up to 40 mm long and 12 mm wide, has 15 strongly convex whorls with circular cross-section, which are not connected by a seam, but by combining the axial, keel- shaped ridges. The ribs are connected to those of the nearest handling, but not with each other on the same deal. Between the ribs the surface is smooth. The housing outlet is almost circular and has a slightly inflated edge. 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 -extending bands of brown spots. The round, horny operculum has an indented nucleus.

The slim probe head being provided at its base with eyes. The foot has the sole straight, double- edged front and center pits.

Occurrence and distribution

Epitonium clathrus lives below the intertidal zone of sandy or muddy ground to 70 m depth, but can come up the worm to lay eggs in the tidal area.

The scroll is from the Mediterranean to Norway and the Kattegat, widespread in the British Isles, the German Bight and off Heligoland.

Life cycle

The spiral staircase snail is initially males and females later. After internal fertilization, the female lays at the bottom of the intertidal zone, the eggs in long strings with pyramid-shaped capsules. The veliger larvae hatch after about two weeks and make a longer phase by as zooplankton.

Nutrition

Epitonium clathrus eats sea anemones and stony corals ( Scleractinia ). The preferred prey is one the wax Rose ( Anemonia sulcata ). With the pine pieces are cut out of the spoils.