Nudibranchs are a large group of gastropod sea snails. Most of these creatures are relatives of ordinary land slugs. However, nudibranch mollusks differ from the latter by a number of unique morphological features. Proceeding from this, they are ranked as a special, separate detachment of mollusks, where there are thousands of different species.
Appearance
Nudibranch mollusks are morphologically similar to ordinary garden snails. The base of the body of these miniature inhabitants of the seas and oceans is a flat leg, which serves as a means of transportation for them. In the front of the body there are stalked outgrowths. At the ends of the latter are tiny, barely distinguishable eyes. These processes also serve as an organ of smell for nudibranch mollusks.
As for the shell familiar to snails, nudibranchs have none. Their body, outwardly similar to a sponge, is not covered by anything. For most of them, the protection from natural enemies in the environment is poison, which is produced by special cells.
Internal structure
Nudibranch mollusks according to the internal structure of the body are divided into several groups: eolidides and doridids. Representatives of doridids have gills located in the back of the body. The large liver is responsible for the digestion and filtering of substances entering the body. Doridids have a genital opening on the right side.
The mollusks of the eolidida group do not have real gills. They are replaced by the so-called papillas - elongated outgrowths that are arranged in rows on the back of such creatures and produce oxygen from the water. The liver, which is responsible for filtering substances coming from the environment, is divided into separate shares. Like the previous group of mollusks, eolidides have a genital opening, which is always located on the right side. When reproducing, such creatures come into contact with bodies for several moments and fertilize germ cells.
Nutrition
Representatives of nudibranch mollusks feed on small marine creatures. Mostly sedentary organisms become their prey: sponges, sitting jellyfish, bryozoans, sea anemones. Among some species, cases of cannibalism have been recorded, in particular, eating egg-laying of their own kind.
Nudibranchs seek prey by smell. Having found a potential victim, the mollusks crawl on top of it, after which they begin to scrape soft tissues with a radula - a hard grater located in the oral cavity.
Habitat
Nudibranch mollusks are marine animals. Their greatest concentration is observed in tropical regions. They live at a relatively shallow depth. However, among the nudibranchs there are also such mollusks that they are able to conduct active life in the polar waters.
Such creatures are hermits and do not stray into groups. They have no permanent habitats. Throughout life, mollusks are in constant motion, trying to get food for food. True, nudibranch mollusks move extremely slowly. Therefore, they are unable to travel considerable distances from the place of birth.
Sheep leaf
Let's find out all about the nudibranch mollusk sheep leaf. In fact, little is known about this creature today. Outwardly, the mollusk resembles a luminous tangle, which as if consists of greenish fur. In the body of the animal are special cells that produce oxygen through photosynthesis. The front of the slug resembles the head of a tiny lamb, for which the creature got its unusual name. Sheep leaf inhabits the mollusk on the run of the Philippines, Indonesia and Japan.
Glaucus
The nudibranch clam glaucus outwardly resembles a man-made brooch than a sea slug. On the sides of its elongated body of a bluish tint are several pairs of branched processes.
This close relative of snails spends the bulk of time near the surface of the water and does not like to sink to the bottom. To maintain the buoyancy of its own body, the mollusk swallows a bubble of air.
Clam Glaucus is a poisonous creature. Toxic substances it is obtained with food. His main prey are the Portuguese jellyfish , which are known for their extremely poisonous tentacles. Moving in the water column, Glaucus attaches himself to the body of a jellyfish and, as necessary, separates pieces of flesh from it, which he uses as food and matter for laying fertilized eggs.
Nudibranch clam golden lace
We continue to consider the most unusual representatives of the nudibranch order. A very interesting creature is a mollusk called golden lace. In fact, the creature is similar to a piece of lace fabric that shimmers with a bright glow. This peculiar snail without a shell was recently discovered in the Hawaiian Islands.
Janolus
Nudibranch mollusk, Janolus, is another rather unusual underwater creature. This marine inhabitant lives in deep water zones at the very bottom. Outwardly, it resembles a horned snail, whose translucent body is strewn with luminous spikes. In the distance, this tiny nudibranch is like an exotic flower.
Finally
As you can see, there are quite a lot of varieties of such extraordinary creatures as nudibranch mollusks. All of them have a strange and bright look. Therefore, they are in demand among aquarium lovers. In fact, nudibranchs are not only a real decoration of nature, but also take part in the formation of marine ecosystems.