Big pond - inhabitant fresh wateroem. It has a cone-shaped, spirally twisted shell with 4-5 curls, a sharp apex and a large opening - the mouth. The shell serves to protect the soft parts of the body of the mollusk, muscles are attached to it from the inside. The shell consists of lime, covered with a layer of greenish-brown horn-like substance. In body pond Three main parts can be distinguished: the trunk, head and leg, but there are no sharp boundaries between them. Through the head, the front of the body and the leg protrude outward from the mouth. Leg at pond muscular When wave-like contractions of muscles run along its sole, the mollusk moves. Leg pond located on the ventral side of the body (hence the name of the class - gastropods).

The body follows the shape of the shell, closely adjacent to its inner surface. Outside it is covered with a skin fold - a mantle. In front of the body goes to the head. A mouth is placed on the underside of the head, and two sensitive tentacles are located on its sides. From touching them, the mollusk quickly draws its head and foot into the sink. Near the bases of the tentacles on the head are in the eye.

Features of life processes: Prudovik feeds on aquatic plants. In his throat, a muscular tongue is placed, covered with hard teeth. Prudovik from time to time he sticks out his tongue and scrapes them, like a grater, the soft parts of plants, which he swallows. Through the throat and esophagus, food enters the stomach, and then into the intestine. The intestine bends loop-like inside the body and ends near the edge of the mantle with an anus. Unlike all previously studied animals at pond there is a digestive gland, a liver whose cells produce digestive juice. Thus, digestive system pond harder than earthworm.

The breath is pulmonary. Rising periodically to the surface of the water, it fills the mantle cavity with fresh air through a circular breathing hole. The walls of the lung are densely braided by blood vessels; here the blood is enriched with oxygen and carbon dioxide is released. Within an hour, the clam rises for breathing 7-9 times. Next to the lung is a muscular heart, consisting of two chambers - the atrium and ventricle. Their walls alternately contract (20-30 times per minute), pushing blood into the vessels. Large vessels pass into the thinnest capillaries, from which the blood goes into the space between the organs. Thus, unlike annelids, the circulatory system of the mollusk is open, since it communicates with the body cavity and blood does not flow through the vessels all the time. From the body cavity, blood is collected in a vessel suitable for the lung, enriched with oxygen and enters the atrium. Blood pond colorless. Excretory organs are represented by one kidney. The main part nervous system pond constitutes a near-pharyngeal congestion of nerve nodes. Nerves depart from them to all the organs of the mollusk.

Reproduction: Hermaphrodite. Puts off a large number of eggs enclosed in transparent mucous cords. Which attach to underwater plants. Small clams with a thin shell come out of the eggs.

Each newcomer to the aquarium business after some time is faced with the fact that the water becomes turbid, and aquatic plants begin to grow uncontrollably. Cleaning the aquarium and putting it in order takes considerable time. But you can get helpers - one of them is a snail pond. She is a natural cleaner of walls and aquarium accessories. In addition, it is interesting to observe snails no less than fish.

The appearance and structure of the snail pond

Lymnaeidae - the name of the pond in Latin. They live in fresh stagnant water or in bodies of water with a slow course.

The common pond snail has a thin-spiral shell with 5-6 curls, usually twisted to the right. Species with left-handed shells are found only in New Zealand and the Sandwich Islands. The degree of its elongation depends on the current in this particular reservoir - the width can be 0.3-3.5 cm, its height is from 1 to 6 cm. There is a large hole in the sink on the front side.

The color of the pond depends on the natural characteristics of the habitat. Most often, sinks are in a brown palette. And the head and body - from tan to blue-black.

The body of the mollusk consists of three sections - the head, trunk and legs. All these parts are tightly attached to the inner surface of the sink. The head of the snail is large, on the head there are flat triangular tentacles, on the edges of them from the inside there are eyes.

The mollusk breathes through an opening protected by a noticeably protruding blade.

Habitat

A water snail pond is found in Europe, Asia, North America and North Africa. In addition to fresh stagnant waters and slow flowing bodies of water, they are found in slightly salted and salty waters, as well as in geysers. In Tibet live at an altitude of 5.5 thousand meters and a depth of 250 meters.

Varieties of pond

The species differ in the shell color characteristic of each locality, its wall thickness, the shape of the rings and mouth, and the color of the legs and bodies.

The common pond (or large snail) is the most common species in the family of gastropods. The length of the conical shell is 4.5-6 cm, its width is 2-3.5 cm. The spiral of the shell has 4-5 rings, which expand significantly with each revolution, ending with an impressive hole size. The color of the semi-transparent walls is brown. The body has a greenish brown tint. This view everywhere inhabits freshwater bodies of the Northern Hemisphere.

The snail is a small pond (it is also called a truncated pond), the shell has an elongated, pointed, with 6-7 revolutions. The turns of rings are twisted to the right. The walls of the shell are thin, but strong, whitish-yellow, almost transparent. It is 1-1.2 cm long and 0.3-0.5 cm wide. The body color is white-gray, uniform, but dark spots are possible on the mantle. This species is widespread in the nature of Russia; it inhabits swampy water bodies and ponds. Sometimes found in low water in dry ponds.

In an ear species, the opening of the shell resembles the human ear - hence the name of this species. The sink is 2.5 to 3.5 cm high, 2.5 cm wide. Its walls are thin, its color is gray-yellow. The shell rings of this mollusk are no more than 4. The shell has an almost round appearance, since the last revolution is quite large in comparison with others. The body is yellowish-green and grayish-green with many specks. The mantle is gray or spotted. It is found in water bodies with different composition of water. Lives on stones, sunken tree trunks, stems and leaves of aquatic plants.

Other famous pond species:

• fiery (cape);
• oval (ovoid);
• marsh.

Wildlife Behaviors and Life Span

IN habitat the pond dwellers feed mainly on plants. But sometimes flies, fish eggs and other similar small aquatic animals eat.

To breathe, they are chosen from the water column to the surface itself. A snail needs to rise at least 6-9 times a day. But species living at a considerable depth, enough oxygen dissolved in water. The mollusk collects water into the pulmonary cavity, flips upside down in the water and slightly draws it into the sink.

In nature, the pond is infrequently possible to find sitting motionless on a snag. The mollusk is almost constantly occupied - it scrapes algae from stones and eats aquatic vegetation. the pond is about 20 cm / min.

Though most Pond dwellers spend their lives in the water column; they survive well in dry ponds and in water that has crusted ice. The mollusk simply seals the shell with a film, and when moisture appears or thawing, it comes to life.

On average, in conditions wildlife the pond's lifespan is only about 9 months. But with the right content, the snail pond in the aquarium can live up to 2 years.

Aquarium content

Prudovik is a gluttonous mollusk. Therefore, it is better not to plant them in carefully grown chic home "herbalists" - you can lose all aquatic plants. Especially snails to taste soft plants with juicy stems and leaves. But in content the pond is unpretentious.

Basic conditions:

• Water temperature in the aquarium should be maintained at 20-26 ° C. In warmer water, the mollusk will actively multiply, which is undesirable in a small volume of water.
• Hardness of water - moderate, lighting is dim (optimally - a low power fluorescent lamp).
• Aquarium volume any one is suitable, the main thing is to control the population, not allowing the pond dwellers to multiply endlessly. If there are too many individuals, diseases can develop.
• you need a rocky one - pebbles are best, but a coarse sandy bottom is acceptable.
• Clean the aquarium with ponds in the usual way, replacing a third of the water every 7 days. Filter you need a powerful one, the direction of the jet is preferably horizontal.

Before settling in new ponds, it is necessary to quarantine them for several days. It is recommended to buy shellfish at pet stores. Since in markets snails can be freshly caught in a pond and infect the entire aquarium with infections.

With whom you can live together in the same aquarium

Feeding at home

Prudoviki prefer plant food. They do not need frequent additional top dressing - algae, rotted parts of plants and fish waste are quite enough for nutrition. The mollusks, like a grater, clean all these residues from the walls and soil with long, powerful tongues. You can also give them:

• fresh pumpkin
• apples
• zucchini
• white cabbage,
• broccoli,
• tomatoes
• carrot,
• greenery grown in the country (cut everything into small pieces).

From time to time, ponds need mineral top dressing - calcium is needed for shells. It is contained in chalk, egg shells, sepia - all this must be given in crushed form.

Breeding

Prudoviki are hermaphrodites. Propagate both one at a time and in a flock. Caviar is laid several times during the year. That is, throughout the life of the offspring of about 500 clutches. Clutches of eggs are attached to the leaves of plants.

The masonry consists of small transparent eggs bound together by mucus, forming an oval-shaped sac. If favorable conditions contribute to this, one individual within 4 months makes up to 25 clutches of 80 eggs.

The incubation period is 14-20 days. Newly hatched babies already have thin shells.

Prudoviks reach puberty at about 7 months.

Diseases

These snails are resistant to disease, but they themselves are often carriers of infection (which can hardly be determined by eye). They themselves get sick with a fungus - visually this manifests itself in the form of a white coating on the sink. Therapy - regular baths with manganese and saline solutions, prolonged quarantine.

How much does a snail pond

In order to avoid infections, it is better to purchase ponds in specialized pet stores, rather than from private owners, and not to catch them on their own in water bodies. The average cost of an adult is about 50 rubles.

Contact hazard

In this article, we will consider who the pond is, what features it has, where there is much more about this wonderful clam. What varieties of ponds exist and how they look.

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

Big and small pond

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

Big pond It is about 5 cm long and has many distinctive features from the brothers.

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

Due to the structure of the shell, he received an asymmetric body for a better fit in the "defense", the connection of the shell with the body is due to the muscle. The muscle allows the animal to be drawn into the shell, and with the help of a pronounced leg, the mollusk can crawl back.

In internal structure ponds of any type everything is arranged simply. The main bodies are:

1. digestive complex;
2. leg;
3. eyes;
4. excretion and respiration system;
5. sole and glands of mucus secretion.

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

The circulatory system is open, and the mollusks move due to a powerful leg that glides over any surface due to the secretion secreted by the glands.

These animals are unique and do not need to be killed. . They do not harm anyonenor to gardens, because they feed on plant foods, which are easily processed (that is, weeds of the type ephemera (wheat grass, wood lice). Also, snails have healing properties, they are proper nutrition and use, mucus is secreted that nourishes human skin and regenerates epithelial cells.

Small pond

Who are the ponds in general, you know from the previous paragraphs, now we will focus on the small. In nature, there are several small ponds:

There are small snails in all gardensare small and beautiful appearance. Be supportive of snails, they do no harm, more good.

Common pond

There is an ordinary pond in the middle lane - Russia, Europe. The pond is large, one sink is 7 cm, not including the body. The pond is breathing with nothing more than a miniature lung, the circulatory system is open, feed on hard plant foods, detritus and midges. The external structure does not differ from a large pond, 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 cochlea moves due to the secretion of mucus and the outer sole, which allows it to move quickly enough at different distances. Snail mucus is rarely used in cosmetology, but most often the mollusk is kept for decoration.

Mollusks become attached to people - breeders, so if a snail is loved, then do not give it to others, otherwise the weak heart of the animal will not stand it.

Now let's take a look at the pond photo

Snails big pond

The pond family includes the well-known and widespread around the world freshwater pulmonary mollusks.

Of the large number of species belonging to this family, the common pond is the most famous due to its large size, the largest specimens of which reach 7 centimeters. From early spring to late autumn, one can observe these snails in ponds, in river backwaters, and small lakes. It is interesting to watch how these bulky snails crawl along aquatic plants or along the bottom of a reservoir. Especially a lot of them happen in the middle of summer among floating leaves of egg capsules or water lilies.

Prudoviks are omnivores, therefore, crawling along the leaves and stems of aquatic plants, they scrape off algae from them with a radula, and at the same time absorb small animals that come in their way. Prudovik is one of the most gluttonous inhabitants of fresh water. He eats not only plants and animals, but also corpses.

Often you can see how the pond, rising to the surface of the water and hanging to it from below with the wide sole of the foot, slides slowly and smoothly in this position due to the surface tension of the water film. Ponds rise to the surface of the water for a reason. Although they are aquatic organisms, but, like all pulmonary mollusks, breathe with the help of a lung and are forced to rise to the surface to "swallow" air. The respiratory opening of the pond, leading to the pulmonary cavity, is wide open. The presence of lungs in pond snails indicates that these animals were descended from land mollusks and have already returned to living in water for the second time.

Pond breeding

When mating, the prudniks mutually fertilize each other, because, like all pulmonary mollusks, they are bisexual creatures. Snail caviar is laid in the form of long, gelatinous, transparent cords that are glued to various underwater objects. Sometimes caviar sticks even to the shell of another individual of the same species. Pond eggs are a complex formation, since the egg cell is immersed in a mass of protein, and on top is covered with a double shell. The eggs, in turn, are immersed in the mucous mass, which is dressed in a special capsule, or cocoon. From the inner wall of the cocoon departs a cord attached at the other end to the outer shell of the egg, as a result of which it appears to be suspended from the wall of the cocoon. The complex structure of egg laying is also characteristic of other freshwater pulmonary mollusks. Thanks to these devices, the egg is provided with nutritious material and is protected by powerful shells. Inside these shells, pond fish develop without a free-floating larva stage. It is likely that such protective devices for pond eggs were inherited from land ancestors, where these devices were more important than when living in water.

The number of eggs in the clutch varies quite widely, as well as the size of the entire clutch - the mucous cord. Sometimes you can count up to 270 eggs in one cocoon.

Ponds differ in extreme variability, and the size of the mollusks, the shape of the shell and its thickness, and the color of the legs and torso vary greatly. Along with large representatives, almost dwarf forms are known that are not mature due to adverse conditions and malnutrition. In some ponds, the shell has thick hard walls, and there are also forms with an extremely thin and brittle shell, which breaks at the slightest pressure. The shape of the mouth and curl is highly variable. The color of the legs and torso of the mollusk varies from blue-black to sandy yellow.

This “propensity” for variability played a large role in the evolution of pond fish. Within the species, a large number of local varieties arose, differing by the listed characteristics, and it is often very difficult to determine that this is a geographic subspecies or variation due to specific living conditions in a given reservoir.

Types of Pond

Along with the common pond, a permanent inhabitant of our inland waters, there is another, also highly variable species - the eared pond. In addition, the ovoid pond, the marsh pond and some others live in stagnant water bodies.

Interesting that in deep water lakes Switzerland found ponds living at considerable depths. Moreover, they are already deprived of the opportunity to rise to the surface to breathe air and have developed another device. The pulmonary cavity of these snails is filled with water, and they breathe oxygen dissolved in water. The absence of gills in the pond, unlike the primary aquatic mollusks, again proves their origin from land snails.

The only representative of our fauna from the genus Mixas is close to the ponds, which differs from them in a very thin and fragile shell, almost completely covered with a mantle. Thus, the shell of this mollusk turned from the outer into the inner. These snails live mainly in floodplain ponds and lakes, where sometimes they breed in huge numbers. However, in the middle of summer, snails disappear, as their life cycle ends in one season.

The sink is spirally twisted, without a lid. In some species (slugs), the shell is reduced. Ganglia are concentrated in the head region, forming a periopharyngeal nerve ring. From the right parietal ganglion, the nerve branch departs to the additional unpaired ganglion. Pulmonary mollusks have one atrium, one lung and one kidney.

fig. 1.
A - top view, B - side view: 1 - mouth, 2 - cerebral ganglion, 3 - pleural ganglion,
4 - parietal ganglion, 5 - visceral ganglion, 6 - liver, 7 - pericardium, 8 - lung, 9 - heart, 10 - kidney, 11 - stomach, 12 - sex gland, 13 - mantle cavity, 14 - leg, 15 - head, 16 - anus, 17 - additional unpaired ganglion.

(Fig. 2) - one of the largest land mollusks in Europe. The spherical-swirling shell has 4-4.5 revolutions, reaches a height of 5 cm, a width of 4.5 cm. The shell is usually yellowish-brown in color with dark brown stripes running along it. The color and width of the stripes vary. On the head of a grape snail are two pairs of tentacles, one of which has eyes, the other serves as the organs of smell and touch. It feeds on green parts of plants. Eating vine leaves and buds can be harmful to vineyards.

fig. 2. Grape
snail (Helix pomatia).

The grape snail is a bisexual animal. It has one hermaphroditic gland, in which female and male gametes are formed. The hermaphroditic duct, into which the protein gland flows, leaves the gland. After the infusion of the protein gland, the hermaphroditic duct expands, forming two gutters: a wide one for the ova and a narrow one for the sperm. Next, each of the gutters is converted into independent channels, respectively, the oviduct and vas deferens. The oviduct flows into the uterus, the uterus into the vagina. In addition to the oviduct, the ducts of the receptacle and bags with calcareous needles flow into the uterus. The vagina opens with a genital opening in a special skin retraction - the genital atrium. The vas deferens passes into the ejaculatory canal, piercing the copulative organ, which opens into the genital atrium. During mating, grape snails exchange spermatophores (sperm packets), which are captured by the testes. Fertilization will occur after mating. Eggs that enter the uterus are fertilized by foreign sperm coming from the sperm. The formed eggs are laid in a mink, which the parent individually digs in the soil with its muscular leg.

In some European countries, grape snails are used as food.

fig. 3. Big
pond (Limnea stagnalis).

(fig. 3) and small pond (L. truncatula) - Often found inhabitants of our fresh water bodies. The head carries one pair of tentacles, at the base of which there are eyes. Hermaphrodite. During mating, as in the case of a grape snail, sperm are exchanged, and the eggs are fertilized by foreign sperm. Lay eggs in mucous cords that attach to underwater plants and other objects. Development is direct, without larval stage. They breathe atmospheric oxygen, so they periodically rise to the surface of the water in order to gain a portion of air.

The size of the shell, its shape, the color of the legs and body are characterized by strong variability in a large pond. For example, the color of the body and legs can vary from blue-black to sandy yellow. The length of the shell of a large pond is up to 7 cm. The large pond is omnivorous, feeds not only on plants and small animals, but can also eat dead plant debris and carcasses of animals.

fig. 4.
A - Arion rufus (Arion rufus),
B - limax maximus
(Limax maximus).

A combined group of terrestrial pulmonary mollusks with a partially or fully reduced shell (Fig. 4). On the head next to the mouth opening is a pair of labial tentacles, on top of the eye tentacles that bear eyes. The narrowed section of the body between the head and the mantle is called the "neck". On the neck below, the duct of the gland secreting mucus opens. In addition to this gland, numerous mucous glands are scattered over the entire surface of the body, so the whole body of slugs is covered with mucus. The main purpose of mucus is moisturizing the integument. On the neck to the right is a genital opening. The mantle has the appearance of a flat thickening on the dorsal side of the body. Near the right edge of the mantle there is a respiratory opening leading to the pulmonary cavity. Near the respiratory opening, the anal opening and excretory pore open along the right edge of the mantle. Slugs are bisexual animals. During mating, male gametes are exchanged. Eggs are laid in moist, shaded places.

Most slugs feed on plants, lichens, or fungi. Predatory slugs feed on oligochaetes or other species of mollusks. Active at night, in the afternoon kept in shelter. Slugs settling in areas occupied by agricultural crops can cause significant harm to planted crops. For example, field slug (Agrolimax agrestis) eats sown grains and seedlings of winter wheat and rye, and net slug (Deroceras reticulatum) causes great damage to the harvest of tomatoes and cabbage.

Description of classes, subclasses and orders of the Mollusk type:

• Class Gastropoda

  • Subclass Pulmonata