Garden snail (Cepaea hortensis). Prudoviki: description of freshwater mollusks Which group does the common pond snail belong to

Hello, Dear friends!

Prudovik (Limnaea)

Meet Limnaea or pond snail! A gastropod mollusk native to Europe, Asia, North America.

The main difference between the pond snail and some other species gastropods is not only in appearance. The fact is that this mollusk breathes not with gills, but with lungs! Therefore, it can often be found on the surface of the aquarium.

The appearance of the pond snail is as follows: the snail has an elongated, rounded shell shape.

The top of the shell is pointed and has a right slope. The size of the mollusk: it grows up to 50 millimeters in height, and the total diameter of the shell is up to 28 millimeters. As you can see, friends, this is a rather large freshwater snail.

The pond snail also has eyes that are located on the outside of the triangular flat tentacles. The “leg” is relatively short, but rather broad. Basic color: the body of the mollusk itself is gray or grayish-green in color, and the shell is yellow, light yellow or dirty yellow. This snail is not demanding on the quality of water!

As for food, the pond snail, like many types of gastropod mollusks, is omnivorous. He eats the remnants of fish food and their waste products, loves fallen parts that begin to rot. Also, these snails are scavengers and can dispose of dead fish that have begun to decompose. There is only one "minus" in these mollusks - their indefatigable, downright wild appetite! They are constantly chewing! They love succulent plants very much, so keep that in mind, friends! Therefore, I highly recommend planting plants with hard leaves, such as pondweed, in the aquarium: these snails do not like hard plants.

As for the reproduction of pond snails, everything is somewhat simpler for them than for other species. The fact is that pond snails are hermaphrodite mollusks! At a certain period, these snails hang their eggs on the tips of plant leaves. These icicle cocoons are quite easy to spot. Each cocoon contains up to a hundred eggs. All masonry matures within 25-30 days.

Like this interesting snail! There is a lot of controversy about keeping a pond snail in an aquarium. Some argue that this is an evil mollusk, which, apart from trouble, brings nothing else to the aquarium. Others simply do not advise placing it in an aquarium. In general, how many people - so many opinions! The main thing is to regulate their number and that's it! Remove snail eggs from in time. Moreover, the time for finding the caviar of this snail is almost a whole month!

On this I say goodbye to you, dear friends! All the best to you and see you soon!

Found in Russia and Europe different types pond snails. Among them, the largest is the common pond snail, the shell of which can reach 7 centimeters. All species breathe with lungs, therefore, from time to time they are forced to swim to the surface. You can often observe how the pond snail, the photo of which is presented in this article, smoothly and slowly slides along the lower part of the surface water film, picking up oxygen from the air.

If the molluscs, "suspended" in this way, are somehow disturbed, they immediately release an air bubble from the respiratory hole and fall like a stone to the bottom. The eared pond snail is the closest relative of the common one. Its shell reaches 2.5 centimeters, which depends on the abundance of food and the temperature in its reservoir.

The common pond snail and other species of its family (in addition to those listed above, in our reservoirs you can find ovoid, small and marsh) are very variable. In this case, the shapes, sizes, thickness of the shell, color of the body and legs of snails vary. Along with those that have a strong shell, there are species with a very fragile, thin shell that breaks even with the slightest pressure. There may also be various forms whorl and mouth. The color of the body and legs varies from sandy yellow to blue-black.

Structure

The body of the mollusk is enclosed in a spirally twisted shell, which has a mouth and a sharp top. The shell of the common pond snail is covered with a lime layer of a horn-like greenish-brown substance. It is a reliable protection of his soft body.

In the body of a snail, 3 main parts can be distinguished: the leg, head and body - although there are no sharp boundaries between them. Only the front part of the body, leg and head can protrude from the shell through the mouth. The leg is very muscular. It occupies the abdominal area. Such snails are called gastropods. At the same time, sliding on objects with the sole of the foot or hanging to the lower film of water, the mollusk smoothly moves forward.

The body at the same time copies the shape of the shell, adjoining it very closely. It is covered in the front part by a mantle (a special fold). The space between it and the body is called the mantle cavity. The torso in front passes into the head, which has a mouth on the underside, and two sensitive tentacles on the sides. Prudovik at light touch to them instantly draws his leg and head into the shell. Near the bases of the tentacles there is one eye each.

Circulation

Prudovik ordinary structure has quite interesting. So, he has a heart, which pushes the blood into the vessels. In this case, large vessels are subdivided into small ones. And from them already the blood goes into the gaps between the organs. Such a system is called "unclosed". Interestingly, the blood washes each of the organs. Then she again gathers in the vessels that lead to the lung, after which she goes directly to the heart. In such a system, it is much more difficult to ensure the movement of blood than in a closed one, since it slows down between organs.

Breath

Despite the fact that the snail lives in water, it breathes atmospheric air. To do this, the common pond snail, the structure of which is described in this article, floats to the surface of the reservoir and opens a round respiratory hole at the edge of the shell. It leads to the lung - a special pocket of the mantle. The walls of the lung are densely braided. In this place, there is a release carbon dioxide and enrichment of blood with oxygen.

Nervous system

This mollusk has a near-pharyngeal concentration. From them, the nerves extend to all organs.

Food

The snail's mouth leads to the pharynx. There is a muscular tongue covered with teeth ─ the so-called grater. The common pond snail, the photo of which can be seen in this article, scrapes off plaque from all kinds of microorganisms that form on various underwater objects, and also rubs various parts of plants. Food from the pharynx travels to the stomach and then to the intestines. The liver also aids in its digestion. In this case, the intestine opens with an anus into the cavity of the mantle.

movements

If the caught pond snail is put in a jar, it immediately begins to actively crawl along its walls. At the same time, a wide leg extends from the hole in the shell, which serves for crawling, as well as a head with two long tentacles. By sticking the sole of the foot to various objects, the snail glides forward. In this case, sliding is achieved by wave-like, smooth contractions of the muscles, which can be easily observed through the glass of the vessel. Interestingly, the common pond snail can wander along the lower surface of the water, as we have already discussed above. At the same time, it leaves a thin tape of mucus. It stretches across the surface of the water. It is believed that snails moving in this way use liquids, hanging from below to an elastic film that forms on the surface due to this tension.

Such crawling can be easily observed on the calm surface of the reservoir, going on an excursion or relaxing in nature.

If the pond snail, crawling in this way, under a little pressure again plunges into the water, it will be seen how it again, like a cork, rises to the surface. This phenomenon is easily explained: there is air inside the respiratory cavity. He supports the cochlea as the Prudovik can compress his respiratory cavity arbitrarily. In this case, the mollusk becomes heavier, therefore, sinks to the very bottom. But when the cavity expands, it floats to the surface along a vertical line without any push.

Try to immerse a pond snail floating on the surface of a reservoir in water and disturb its soft body with a touch of tweezers or a stick. The leg will immediately pull back into the shell, and air bubbles will come out through the breathing hole. Further, the mollusk will fall to the bottom and will not be able to independently rise to the surface in any other way than climbing on plants, due to the loss of the air float.

reproduction

The pond snail mollusk is a hermaphrodite, although its fertilization is cross. The snail lays eggs that are enclosed in slimy, transparent cords attached to algae. Eggs hatch into small pond snails with very thin shells.

If you still decide to start an ordinary pond snail, then you need to understand that a water temperature of about 22 ˚С and its moderate hardness are considered a prerequisite for its maintenance.

Mollusks, or soft-bodied, live in the sea, in fresh waters and on dry land. The body of mollusks, as a rule, is covered with a shell, under which there is a skin fold - the mantle. The space between the organs is filled with parenchyma. About 100,000 species of molluscs are known. We will get acquainted with representatives of three classes: gastropods, bivalves and cephalopods.

Lifestyle and external structure. In ponds, lakes and quiet backwaters of rivers on aquatic plants you can always find a large snail - a large pond snail. Outside, the body of the pond snail is dressed in a protective spirally twisted shell about 4 cm long. The shell is composed of lime covered with a layer of greenish-brown horn-like organic matter. The shell has a sharp top, 4-5 whorls and a large opening - the mouth.

The body of a pond snail consists of three main parts: head, torso and legs. Only the leg and head of the animal can protrude from the shell through the mouth. The leg of the pond snail is muscular. When undulating muscle contractions run along its sole, the mollusk moves. The leg of the pond snail is located on the ventral side of the body, and therefore it is classified as a class of gastropods. In front, the body passes into the head. A mouth is placed on the underside of the head, and two tentacles are located on its sides. The tentacles of the pond snail are very sensitive: when touched, the mollusk quickly draws its head and leg into the shell. Near the base of the tentacles on the head is an eye.

The body repeats the shape of the shell, closely adhering to it. inner surface. Outside, the body is covered with a mantle, under it there are muscles and parenchyma. A small cavity remains inside the body, in which the internal organs are located.

Food. Prudovik eats aquatic plants. In his mouth is placed a muscular tongue, covered with hard teeth. From time to time, the pond snail sticks out its tongue and scrapes with it, like a grater, the soft parts of plants, which it swallows. Through the pharynx and esophagus, food enters the stomach and then into the intestine. The gut loops inside the body and ends on its right side, near the edge of the mantle, with an anus. Next to the stomach in the body cavity lies a grayish-brown organ - the liver. Liver cells produce digestive juice, which flows through a special duct into the stomach. In this way, digestive system the pond snail is even more complex than that of the earthworm.

Breath. Despite the fact that the pond snail lives in water, it breathes oxygen. atmospheric air. For breathing, it rises to the surface of the water and opens a round breathing hole on the right side of the body at the edge of the shell. It leads to a special pocket of the mantle - a lung. The walls of the lung are densely woven with blood vessels. This is where the blood is enriched with oxygen and carbon dioxide is released. Within an hour, the mollusk rises for breathing 7-9 times.

Circulation. Next to the lung is a muscular heart, consisting of two chambers - the atrium and the ventricle. Their walls alternately contract (20-30 times per minute), pushing blood into the vessels. Large vessels pass into the thinnest capillaries, from which blood exits into the space between the organs. In this way, circulatory system clam is not closed. Then the blood is collected in a vessel suitable for the lung. Here it is enriched with oxygen and enters the atrium through the vessel, and from there into the ventricle. The blood of the pond snail is colorless.

Selection. The pond snail has only one excretory organ - the kidney. Its structure is rather complicated, but in in general terms resembles the structure of the excretory organs of an earthworm.

Nervous system. main part nervous system the pond snail is a near-pharyngeal accumulation of nerve nodes. Nerves depart from them to all organs of the mollusk.

Reproduction. Prudoviks are hermaphrodites. They lay masses of eggs enclosed in transparent, slimy cords that are attached to underwater plants. Eggs hatch into small mollusks with thin shells.

Other gastropods. Among a large number of species of gastropod mollusks, marine ones are especially famous, thanks to beautiful shells. Slugs live on land, so called because of the abundant mucus they secrete. They don't have shells. Slugs live in damp places and feed on plants. Many slugs eat mushrooms, some are found in fields and gardens, causing damage to cultivated plants.

The grape snail is widely known, which is eaten in some countries.

After starting a new aquarium, novice aquarists often face the problem of pollution, the appearance of unwanted algae. There are many ways to clean the aquarium tank, the best of which, perhaps, is biological, that is, adding natural cleaners to fish. Often, fish owners resort to the help of pond snails. They not only help fight pollution, but are also interesting in terms of observing their behavior.

Description, types

The pond snail (lat. Lymnaeidae) is a snail belonging to the genus of pulmonary molluscs. As the name implies, it lives in fresh water bodies with stagnant water or water with a very slow current.

Did you know? Snails are among the most ancient animals on earth. According to scientists, they appeared over 500 million years ago..

The body of the mollusk is divided into three parts: head, body and leg. The pond snail has a fine-spiral shell, on which there are five or six whorls, mostly twisted to the right. Left-handed are found in the inhabitants of New Zealand and the Sandwich Islands. The shell opening is large, rounded in front. The shape of the shell depends on what current is characteristic of the reservoir where the snail lives. Its dimensions range from 1 to 6 cm in height and from 0.3 to 3.5 cm in width. The body is tightly attached to the shell. The head of this mollusk is large. It has flat triangular tentacles with eyes on their inner edge. The hole through which the pond snail breathes is protected in the form of an outstanding blade. The color of the snail depends on the living conditions. The shell is usually brown. The head and body can be colored from black with a blue tint to yellow with a brownish tint.
In nature, the pond snail is represented by many species that live in the Northern Hemisphere, on the territory of Eurasia, North Africa, North America. Some of its representatives can be found in geysers, sulphurous, slightly saline and salty waters. You can find them even at an altitude of 5.5 thousand meters in Tibet and at a depth of 250 m.

Did you know?The tiny snail brain is divided into four sections and is quite efficient. Scientists claim that these mollusks have the ability to take independent solutions. After conducting more detailed studies of two neurons that are responsible for the feeling of hunger and the decision to go for food, they decided to use this data to work with the simplest algorithms in robotics.

Each species is distinguished by the characteristic coloration of the shell, body, legs, as well as the shape and thickness of the shell walls, the shape of the whorl and mouth.

Let's take a closer look at the most famous species:

1. Prudovik ordinary, he is big. The largest in our area and the most famous representative of the family. The shell is elongated, conical, 4.5-6 cm long and 2-3.5 cm wide. It is twisted in a spiral with 4-5 turns, which quickly expand, forming a large hole. Its color is brown, the walls are thin and translucent; the body of the mollusk is greenish-gray. The species is widespread, found throughout the Northern Hemisphere in various freshwater reservoirs.
   
2. This species has an elongated, pointed to the top and strong shell. Curls twist to the right, have six to seven turns. The shell is thin, almost transparent, pale yellow. Its dimensions are small: length - 1-1.2 cm, width - 0.3-0.5 cm. The body and mantle of this pond snail are of light gray shades. There are dark spots on the mantle. The species is distributed on the territory of Russia, lives in ponds, swamps, puddles. It can live along the banks of drying water bodies.
   
3. Ear. So named because the mouth of the shell in appearance is very similar to the human ear. Its shell is small - 2.5-3.5 cm in height and 2.5 cm in width. Has thin walls. Painted in greyish yellow. Has up to four turns. The last turn is very large. The body is colored green-gray or yellow-green with numerous inclusions. The mantle can be monophonic - light gray, or spotted. The ear pond snail lives in various reservoirs, lives on plants, snags, stones.
   
4. ovoid or oval. Like the auricular pond snail, the ovoid shell curl makes up a third of the mouth. The shell has thin walls, so it is very fragile. In an adult, it is 2-2.7 cm in height and 1.4-1.5 cm in width. The shape of the mouth is ovoid. The shell is painted light pink, shiny and almost transparent. The body color is light gray or light olive. The mantle is also light grey. Habitat habitats of the egg-shaped pond snail - lakes, quiet rivers. It can live both in the coastal zone and at depth.
5. In the swamp pond snail, the height of the shell reaches 3.2 cm, the width is 1 cm. In appearance, this species is similar to the common pond snail, but differs from it in that its shell has the shape of a sharp cone with a small hole. It is dark brown in color. In addition, the marsh one is smaller than the ordinary one: the height of the shell is 2-3 cm, the width is 1 cm. There are six to seven whorls on the shell. Her walls are thick. The body is greenish gray in color. The mantle is light. It lives in shallow water bodies - swamps, puddles, streams, ponds.
   
6. Frilled or frilled. It got its name due to the fact that its shell is completely or partially covered by a mantle. The shell of the raincoat is shiny, smooth. May be colorless, yellowish or yellow-horny. It is small in size, its height is 1.9 cm, width is 1.2 cm. It has 2.5-4.5 curls. The last one is very big. The shell is shaped like a ball. Mouth - oval, large. The body is painted in olive s gray color with numerous inclusions. The mantle is yellow-brown or yellow-green with large light spots. Lives in lakes, quiet rivers, in shallow water.

Habitat in nature

In nature, common pond snails eat mainly plants. However, their diet can also include animal food (flies, fish eggs, etc.) and bacteria. They breathe, crawling out of the water to the surface. On the day they need to carry out from six to nine such lifts. Those snails that live at great depths are able to exist due to the air dissolved in water. They draw water into the lung cavity. Pond snails can swim - they turn the sole upside down and give it a slightly concave shape.

Did you know? Snails have no hearing and voice, very poor eyesight, but their sense of smell is well developed - they are able to smell food at a distance of about two meters from themselves. The receptors are located on their horns.

AT vivo these snails are rarely seen idle, usually they are “in a hurry” somewhere, busy with something - for example, scraping algae from stones. Max Speed, which they can develop - 20 cm per minute.
It is interesting that these mollusks are able to survive when the reservoir dries up, sealing the shell with a dense film, as well as when the pond is covered with ice - after thawing it, they come to life and continue their vital activity. average life expectancy aquarium pond snail- two years in wild nature- nine month.

Prudovik is an unpretentious aquarium inhabitant. The main conditions for its maintenance are water temperature not lower than 22 ° C, its moderate hardness and weak light - preferably fluorescent with a minimum power.
With more warm water snails will breed more often and actively, and this is not desirable for home aquariums. The size of the aquarium is not critical. The soil is rocky. It can be pebbles or coarse sand.

Special cleaning for shellfish is not required. All you need is the standard procedures that every aquarist must follow:

• weekly water change by 30%;
• aeration;
• filtration.

Nutrition, mineral supplements

Every owner of an aquarium who is going to place a pond snail in it will be interested in the question of what he eats and where to get food for him. There will be no problems with this, since he can eat both what the fish did not eat, and their excrement, rotten plants. A person can prepare for him a salad of finely chopped greens, cabbage, zucchini, pumpkin, tomatoes, and other vegetables and fruits.
With the addition of pond snails to the aquarium, you should be careful, because when they reach adulthood, they can be very voracious and eat most underwater vegetation. Occasionally, snails will need to be fed with mineral supplements. The main thing for them is calcium, so you can sprinkle them with crushed eggshells, chalk, sepia.

Important! Do not plant pond snails in a tank where soft and succulent underwater plants grow. It threatens the death of the latter. These snails are too tough for only algae with hard, dense sheets.

Compatibility with other inhabitants of the aquarium

Diseases

Snails rarely get sick. But they themselves serve as a source of infectious ailments for other aquarium inhabitants. Moreover, the danger lies in the fact that usually the presence of an infection in the body of a mollusk does not affect its appearance in any way, therefore it is not always possible to immediately determine whether it is dangerous for fish or not. In a small pond snail, the most common disease is fungal infection - its shell is covered with a white coating.
Treatment will consist in baths with the addition of salt solutions or potassium permanganate. Also, if the mollusk does not consume the necessary amount of vitamins and minerals, the walls of its shell can become thin and get damaged. When observing this problem, it is worth feeding the snail with substances containing calcium. Small cracks will disappear on their own some time after the start of treatment. But the deep ones will need to be “glued” with a special preparation sold in zoological stores.

Breeding

Pond snails reach sexual maturity at six to eight months. Since they have no sexual differences, representatives of the pond family reproduce by laying eggs, usually from 20 to 130 per clutch. This process can occur in them several times a year, and in a lifetime one individual is capable of producing offspring about five hundred times. Mollusks lay their eggs on the leaves of plants. Incubation occurs within 14-20 days. The eggs hatch into thin-shelled babies. Thus, pond snails, in addition to being very voracious, are also prolific. Therefore, the question of their breeding among aquarists is not worth it. More often another problem arises - how to prevent their frequent reproduction and overpopulation of the aquarium. If the task is to breed these mollusks, then you can stimulate the breeding process by raising the water temperature by a couple of degrees.

Did you know? The largest sea snail is considered to be the giant Australian trumpeter, whose shell reaches 91 cm and weighs 18 kg. The tiger Achatina is recognized as the largest land mollusk - with a shell 27.5 cm high and weighing about 1 kg.

Snails do not have to be planted in the aquarium themselves. They may appear unexpectedly - their eggs are brought along with underwater plants. In this case, the owner needs to organize their proper maintenance and ensure that the number of individuals does not exceed the capacity of the aquarium tank. If you manage to control their reproduction, then the presence of pond snails will certainly benefit the fish dwelling - they can help get rid of unfriendly algae that settle on the decor, walls and plants, and keep their place of residence clean. Shellfish are indispensable cleaners for spawning aquariums. Overpopulation by snails threatens with oxygen deficiency, because of which, first of all, the fish will suffer. Thus, pond snails are possible, but not desirable, to be kept in an aquarium. On the one hand, they are able to clean the tank, get into places where they can’t get human hand, get rid of unnecessary algae. In addition, they do not require special care and nutrition. On the other hand, these snails can cause serious damage to underwater plants and, as a result, the beauty of the aquarium. They are often placed in an aquarium without live algae by beginners. Experienced aquarists prefer to deal with snails of other species.

In this article, we will consider who a pond snail is, what features it has, where it is found, and much more about this wonderful mollusk. What types of pond snails exist and what do they look like.

Any from pond snails, whether ordinary, small or large, is a snail that lives in ponds and gardens where there is enough moisture.

Large and small pond

The large pond snail belongs to the class of gastropods, which is the most numerous and diverse in comparison with other classes of gastropods. There are more than 90 thousand species of such mollusks in nature, and their habitat is not only ponds, but also the sea and land.

big pond snail is about 5 cm long and many distinctive features from brothers.

Let's talk about the external structure of a large pond snail. It consists of three parts that are noticeable and perfectly distinguishable from each other. The body outside the shell is covered with a mantle to protect the internal mucosa, the shell of a mollusk is twisted for convenience in a spiral of 5 turns. This structure of the shell provides reliable protection of the body from irritants, mechanical damage. . The sink contains lime for the basis of the structure of spirals, and covers it from above organic matter horn-like type (this is on the horns of cattle, etc.).

Due to the structure of the shell, he received an asymmetric body for better accommodation in the "protection", the connection of the shell with the body is carried out due to the muscle. The muscle ensures that the animal is drawn into the shell, and with the help of a pronounced leg, the mollusk can crawl back.

In internal structure pond snails of any type, everything is arranged simply. The main organs are:

1. digestive complex;
2. leg;
3. eyes;
4. excretory and respiratory system;
5. sole and mucus secretion glands.

The snail feeds on plant food in a crushed form, then food from the tongue (has a “grater”) passes into the throat, is processed by the secretion of splitting and processed in the stomach and intestines.

The circulatory system is open, and the molluscs move due to the powerful leg, which glides over any surface thanks to the secret secreted by the glands.

These animals are unique and do not need to be killed. . They don't harm a person, nor gardens, because they feed on plant foods that are easily processed (that is, weeds of the ephemeral type (wheatgrass, wood lice). Snails also have healing properties, they are proper nutrition and application secrete mucus that nourishes human skin and produce regeneration of epithelial cells.

Small pond snail

Who are the puddlers in general, you know from the previous paragraphs, now we will talk about small things. In nature, there are several small pond snails:

Small snails are in all gardens, are small in size and beautiful appearance. Be supportive of snails, they do no harm, more good.

common pond snail

Meets common pond snail in middle lane- Russia, Europe. The pond snail has a large size, one shell is 7 cm, not including the body. The pond snail breathes with nothing more than miniature lungs, the circulatory system is not closed, they feed on hard plant foods, detritus and midges. External structure does not differ from a large pond snail, except that the body does not always correspond to the size of the shell, sometimes smaller than the shell. Shell color - mother-of-pearl, brown. Body color - brown, gray, white.

Snails can easily survive both in nature and in the artificially created environment of a terrarium, aquarium. The snail moves thanks to the secretion of mucus and the outer sole, which allows it to move quickly enough over various distances. Snail mucus is rarely used in cosmetology, but most often the mollusk is kept for decoration.

Mollusks are attached to people - breeders, so if you fell in love with a snail, then do not give it to others, otherwise the weak heart of the animal will not stand it.

And now let's take a look at the photo of the pond

Snails big pond