Скачать или смотреть Dotted Sea Slug - Peltodoris atromaculata - Leopardenschnecke

Dotted Sea Slug - Peltodoris atromaculata - Leopardenschnecke

Peltodoris atromaculata, more commonly known as the dotted sea slug or sea cow, is a species of sea slug, a dorid nudibranch, a marine gastropod mollusk in the family Discodorididae. It dwells in salt water up to the depth of 40m. It is exclusively found in precorralligene and coralligene communities and is very common in such communities.

Peltodoris relies exclusively on the sponges Petrosia ficiforms and Haliclona fulva as its food source, which is detects using chemotaxis. There are no other species know to prey on P. ficiforms and H. fulva, due to the fulvinol-like polyacetylenes produced by the sponges as a secondary metabolite, which are known to be cytotoxic. This lack of competition allows Peltodoris to relatively unrestricted by food availability. While Peltodoris prefers to feed on Haliclona over Petrosia, Petrosia are more numerous leading Peltodoris to feed mainly on Petrosia. In rare occasions, Peltodoris will feed on parts of its own mantle tissue. There are no observed daily and seasonal variation in the feeding habits of Peltodoris.

Defense mechanisms
Peltodoris has two main defense mechanisms that have been confirmed: mantle spicules and disruptive coloration. Unlike most dorid species, Peltodoris do not utilize chemical defense through the absorption of cytotoxic chemicals from their prey.

Mantle spicules
The mantle spicules are composed of calcite (CaCO3) and brucite (Mg(OH)2) and fluorite (Ca2F), with calcite making up the largest percentage and fluorite the least. These deter predators by causing physical harm when the predator comes into contact with the spicules.

Disruptive coloration
The bright coloration on the mantle of Peltodoris serves as aposematic signals which warns predators of protective mechanisms, making predators less likely to attack.

Mucus
A colorless mucus secreted from the mantle of Peltodoris both when the animal is stressed and under normal conditions. The fluid has a relatively neutral pH between 6 and 7. However, it is uncertain whether the mucus plays a role in defense.

Autotomy
Certain Peltodoris individuals will undergo autotomy of the mantle margin before death. During this process, most of the mantle is lost except small parts around the gills and head. Most slugs die right after autotomization, a small number are able to survive for a few hours after autotomization but only for maximum 2-3 hours. Unlike in many other animals, autotomy in Peltodoris is not reversible and is not used for defense, but merely a senescent process.

Source: https://en.m.wikipedia.org/wiki/Pelto...

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May 2021, Adriatic Sea, Dalmatia, Croatia