Adamsia palliata

Anemone Hermit Crab ( Pagurus prideaux ) with a housing on which a contracted Mantelaktinie is ( the purple spotted area).

The Mantelaktinie ( Adamsia palliata ) is a Seeanemonenart colonized the shells of snails. The name derives from the fact that it grows around these shells, and thus a " coat" forms.

Features

The " body" of the Mantelaktinie is formed from ectoderm, endoderm and mesogloea and is based on the oral disc at the upper end to the basal basal disc. He is dirty white, with pink, purple and purple spots and strongly flattened. If necessary, the anemone may contract, that is, it draws its tentacles almost complete.

The mouth opening is oval and can reach a diameter of up to five centimeters. It is surrounded by several circular rows of tentacles. The approximately 384 white tentacles are up to a centimeter long. Slightly below the mouth opening, which is lighter than the body, a thin, pink ring apparent.

The Mantelaktinie sets headlong firmly on the bottom of snail shells. Their tentacles broom-like stripes on the ocean floor and can accommodate in this way food. With their basal disc it grows around here, the shell, the Fußscheibenränder collide at full sheathing at the top of the case again. The basal disc can reach a diameter of up to fifteen centimeters and is white to almost maroon colored, also with pink and purple dots. The preferred species of snail, whose empty Geäuse the Mantelaktinie alone, rarely in pairs, locates may vary. Examples are the whelk ( Buccinum undatum ), Scaphander Lignarius, as well as several centrifugal screw ( Trochidae ). These shells are populated mostly by Anemone Hermit Crab ( Pagurus prideaux ); but there are also other Pagurus species.

When threatened, or to prey acquisition, shoots A. palliata purple, rarely white, poisonous stinging threads of ( nematocysts ) from the basal region.

Dissemination

One finds A. palliata especially on muddy to sandy soft bottoms to a maximum of two hundred meters water depth.

It comes in the North Sea, the north-eastern Atlantic off to the south of the Azores and the Mediterranean.

Development

During the summer months Adamsia palliata are several hundred eggs from through their mouth into the sea. These are fertilized in the water and develop into planula larvae. These in turn develop into juvenile sea anemones, and look for a suitable host, they then grow around.

Symbiosis with Pagurus prideaux

The symbiosis between Pagurus prideaux and Adamsia palliata is a Ektosymbiose. The symbiosis is not obligate, meaning that the symbionts do not depend on each other. It A. palliata specimens were observed, which survived for years without the partner.

The advantages for the anemone primarily consist of mobility. This comes as an enlarged their scope benefit when catching prey and as an extended living space, since they can settle using the hermit on muddy bottoms, where they would otherwise einsedimentieren. In addition, the oxygen supply improved by the movement of the hermit.

The feeding behavior of the cancer provides another advantage: The hermit crab swirls the sand on around them to filter out food, which also benefits the diet of Mantelaktinie.

P. prideaux benefited especially from the stinging cells of Mantelaktinie. When threatened, the sea anemone stinging threads shoots out, still remain liable for several minutes at the snail's shell and thus ensure adequate protection.

If the Mantelaktinie is too large, it lets out a chitinhältiges secretion that the snail shell increased. This has the advantage that it can live longer in the shell, whereby the symbiosis couple does not have to relocate for the anemone hermit. Sometimes it even comes to a complete resolution of the screw shell and the anemone itself forms the housing for the cancer.

The coexistence of symbionts goes so far that P. prideaux "his" Mantelaktinie sometimes mitübersiedelt in a housing relocation.

Taxonomy

The taxonomy of the species has been controversial since the 1980s. After she was done for centuries under the species name palliata, arranged RL Manuel them nomenclatural reasons in 1981 in his book " British Anthozoa " the name Adamsia carciniopados AW Otto, 1823, to. The name comes from palliata originally a publication of Johann Baptist Bohadsch, which was, however, suppressed for nomenclatural purposes by the ICZN, because not all names listed in it are binary ( Opinion 185). Cornelius and Ates 2003, but then argued that the name Adamsia palliata had to be preserved. Before Otto in 1823 had, according to them O.F. Müller 's name palliata 1776 used and thus made available nomenclatural their view. The "World Register of Marine Species" writes the name Adamsia palliata instead Fabricius, 1779 and follows the opinion of Daphne G. Fautin in " Hexacorallians of the world".