Prudovik ordinary: description, food, enemies and habitat

Anonim

In Russia and Europe, there are different types of pond cleaners. Among them, the largest is the common pond snail, whose shell can reach 7 centimeters. All species breathe light, therefore, from time to time they are forced to float to the surface. It is often possible to observe how the snail pond snail, the photo of which is presented in this article, smoothly and slowly slides along the lower part of the surface film of water, gathering oxygen from the air.

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If the mollusks “suspended” in this way are somehow disturbed, they immediately release a bubble of air from the respiratory orifice and fall like a stone to the bottom. Prudovik eared is the closest relative of the common. Its shell reaches 2.5 centimeters, which depends on the abundance of feed and the temperature in its reservoir.

Prudovik ordinary and other species of its family (except for the above, in our waters can be found ovoid, small and marsh) are very variable. They vary with the shape, size, thickness of the shell, the color of the torso and legs of snails. Along with those that have a strong shell, there are species with a very fragile, thin shell that breaks even with the lightest pressure. Also may be different forms of curl and mouth. The color of the torso and legs varies from sandy-yellow to blue-black.

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Structure

The mollusk's body is enclosed in a spiral-twisted shell, which has a mouth (large opening) and a sharp apex. The shell of an ordinary pond snail is covered with a layer of lime of a hornlike greenish-brown substance. She is a reliable protection of his soft body.

There are 3 main parts in the body of the cochlea: the leg, the head and the body - although there are no sharp boundaries between them. Only the front part of the body, leg and head can protrude out of the shell through the mouth. The leg is very muscular. It occupies the abdominal part of the body. Such snails are called gastropods. At the same time, sliding on the objects by the sole of the foot or hanging on to the lower water film, the clam moves forward smoothly.

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The body at the same time copies the shape of the shell, adhering to it very closely. It is in front of the 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 with a light touch to them instantly pulls into the sink leg and head. Next to the bases of the tentacles are located on one eye.

Circulation

Prudovik ordinary structure is quite interesting. So, he has a heart that pushes blood into the vessels. At the same time large vessels are divided into small ones. And of these, blood is already flowing into the gaps between the organs. This system is called "unlocked". Interestingly, the blood washes every organ. Then she gathers again in the vessels that lead to the lung, and then goes directly to the heart. In such a system, the movement of blood is much more difficult than in a closed one, since it slows down between the organs.

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Breath

Despite the fact that the snail lives in water, it breathes atmospheric air. To do this, the common pond snail, whose structure is described in this article, floats to the surface of the reservoir and opens a respiratory round 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 covered with blood vessels. In this place, carbon dioxide is released and blood is enriched with oxygen.

Nervous system

This mollusk has a pharyngeal concentration of ganglia. From them nerves go to all organs.

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Nutrition

The mouth of the snail leads to the pharynx. There is a muscled tongue covered with teeth, so-called grater. Prudovik ordinary, a photo of which can be viewed in this article, she scrapes plaque from all sorts of microorganisms that are formed on various underwater objects, as well as tert various parts of plants. Food from the pharynx is sent to the stomach, and then to the intestines. Also its digestion contributes to the liver. The intestine opens with the anus in the cavity of the mantle.

Movements

If you put a caught pond snail in a jar, he immediately begins to actively crawl along its walls. At the same time, a wide leg extends from the opening of the shell, which serves for crawling, as well as a head with two long tentacles. Sticking the sole of the foot to various objects, the snail slides forward. In this case, the glide is achieved by undulating, smooth muscle contractions, which can be easily observed through the glass of the vessel. It is interesting that the common prudnik can wander along the lower surface of the water, which we have already mentioned above. In doing so, it leaves a thin ribbon of mucus. It stretches across the surface of the water. It is believed that the cochlea, moving in this way, use the surface tension of the liquid, hanging from below to the elastic film, which is formed on the surface due to this tension.

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

If the mollusk pond snail crawling in this way, under a slight pressure again sinks 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. It supports the snail as a swim bladder. Pondovik its respiratory cavity can compress 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 jolt.

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Try to pond fish, floating on the surface of the reservoir, immersed in water and its soft body to be disturbed with a touch of tweezers or sticks. The foot will immediately be drawn back into the sink, and air bubbles will be released 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, except climbing on plants, due to the loss of the air float.

Breeding

The mollusk pond snail is a hermaphrodite, although its fertilization is cross-sectional. The snail lays eggs, which are enclosed in mucous transparent cords attached to algae. From the eggs appear small pond snails with a very thin shell.

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Content pond

Some aquarists allow the maintenance of pond cleaners in one common vessel, not realizing that this is often simply unacceptable. After all, if, say, an ampullary is grown mainly in artificial conditions (in an aquarium), the snail is placed there directly from a pond, a small lake, or a standing reservoir. Prudoviki, which were caught in natural conditions, are more likely to be a source of infectious diseases and parasites of fish. Very often, young aquarists are offered to purchase mollusks in the poultry market and in various pet stores.

If you decided to start a pond snail, then you need to understand that water temperature is about 22 ° C and its moderate hardness is a prerequisite for its content.

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