Earthworm (lat. Lumbricidae) belongs to a class of invertebrates and earthworms suborder (Haplotaxida).His body is composed of the ring segments, the number of which can reach 320!These animals are widely distributed in all corners of our planet.No it only in Antarctica.Very often the children are interested in how earthworms move.In this article we analyze in detail the issue and at the same time learn about their physical appearance, lifestyle and mode of reproduction.
Lifestyle earthworms
If in the morning or after rain to walk through the garden, vegetable garden, then, as a rule, can be seen on the ground a small handful of soil ejected by worms, and in the puddles and see themselves.Due to the fact that these individuals crawl on the ground after the rain behind them, and the name stuck.Earthworm (photo, above, demonstrates this invertebrate animal) also creeps on the earth's surface at night.As a rule, he prefers humus-rich soil, so it is rare to find in sandstones.Dislikes earthworm and marshy soils.These features are explained by the physiological characteristics Lumbricidae.The fact that the worms breathe entire surface of its body coated mucosal epidermis.In saturated soil moisture solution is too little air.As a result, there is an earthworm pants.By the way, this explains his behavior in the rain.Dry soil is also detrimental to the representatives Haplotaxida: their skin is dry, and breathing stops.In wet and warm weather earthworms (photo below shows the Lumbricidae throughout the "glory") are held closer to the ground.With decreasing temperature, as well as with the onset of the dry season, they crawl down the soil.
Appearance earthworms
Adults reach 30 centimeters in length, although there are some instances and larger sizes.The body of the earthworm slippery, smooth, cylindrical in shape, consists of segments - piecework rings.This constitution is due to lifestyle Lumbricidae: This structure facilitates the movement of soil.Number of piecework rings reaches two hundred.The surface of the body which conditionally might be called back, convex, abdominal - flat and lighter.The body of the earthworm, where its front end is completed, there is a thickening which is called fascia.There are special glands secreting a sticky liquid.During the multiplication of belt formed egg cocoon eggs develop in it.
Getting around earthworms?
representatives Haplotaxida crawl.First they pulled the front end of his body and cling setae, which are located on the ventral side of the rings, the uneven ground.After that there is the contraction of muscles and the back part of the body is pulled forward.The movement of the worm in the ground characterized in that it paves the passages in the soil.This pointed end of the body, he pushes the earth, and after squeezing between its particles.Interestingly, as the earthworms move into denser layers.During the movement, they swallow the earth and passed it through the intestines.The soil worms tend to swallow at a considerable depth, and thrown through the anus is already at the top, near his mink.It is often seen in the summer on the ground in the form of lumps and elongated "laces".
Earthworm and its biology
Worms have well-developed muscles, due to which, and made possible this way of movement.Their muscles are located below the epidermis, in fact, they, along with the skin form a kind of skin-muscular sac.Muscles are arranged in two layers.Immediately below the epidermis are circular muscle and beneath them - the second, thicker longitudinal layer (composed of long contractile fibers).Upon compression of the longitudinal muscles of the earthworm's body becomes thicker and shorter.With the reduction of the ring musculature, on the contrary, - long and thin.Alternate reducing both muscle layers, carried out under the influence of branching in the muscle tissue of the nervous system and causes movement Lumbricidae.
Moving worms greatly facilitated by the presence on the lower part of the body of small bristles.They can feel if you hold a wet finger on the abdomen of the worm from the rear to the front end.With these bristles earthworms not only move in the soil, but also "grab" for the land when they are trying to get.They also help to rise and fall on the work already done by earth moves.This concludes our deal with the question of how to move earthworms, and go on to be as interesting facts about the life Lumbricidae.
Circulatory System Circulatory System
earthworms consists of two longitudinal blood vessels - the ventral and dorsal, as well as connecting them to the branches.Due to muscle contraction of the walls there is a movement of blood throughout the body.Blood earthworms scarlet.With the help of a connection between internal organs, as well as for the exchange of substances.Circulating blood carries nutrients from the digestive compounds, and oxygen coming from the skin.Simultaneously, the tissue is derived from carbon dioxide.In addition, the blood in the organs of excretion outputs the unnecessary and harmful compounds.
Nutrition earthworms
basis of power representatives Haplotaxida make rotten remains of plants.Usually at night earthworms pulls a hole in their leaves, stems and the like.In addition, they can pass through your intestines humus-rich soil.
irritation earthworms
Special senses earthworms do not have.They perceive external stimuli through the nervous system.Worms highly developed sense of touch.Nerve cells that are responsible for it, placed over the entire surface of the skin.The sensitivity of the earthworm is so great that most light tremors make them as fast as possible to hide in burrows or in the deeper layers of the earth.However, the value of sensitive nerve endings is not limited to the function of touch.Scientists have found that using these cells earthworms are able to feel the rays of light.For example, if a worm at night to send the flashlight beam, it will disappear at high speed in a safe place.
answer any irritation on animals, carried out through the nervous system, called reflex.To distinguish different kinds of reflexes.Thus, the reduction of the earthworm body from touching him and his movement the sudden illumination of a safety function.This is a protective reflex.Experiments scientists have shown that earthworms can smell.Because of the sense of smell, they find food.
Reproduction
Earthworms reproduce sexually, though generally protostomes are hermaphrodites.Each representative Haplotaxida have male organs, which are called the testes (in which sperm develop), and the female organs called ovaries (they formed the egg).Earthworm lays its eggs in the mucous cocoon.It is formed of a substance which is released through the band.Next cocoon as clutch slips off the body and pulled together at the ends.It remains in the ground as long as the young worms to pass out of it.Cocoon is to protect the eggs from moisture and other adverse effects.
And what do you want the worms?
This section will be useful for those who think that earthworms are only required for fishing.Of course, the fishermen without them nothing to do without them in the river, but it's not all good from the representatives Lumbricidae.The role of earthworm in nature is so great that it can not be overemphasized.They contribute to the decomposition of organic matter in the soil.In addition, earthworms enrich the land of valuable fertilizer - humus.Also, they are a kind of indicator: if the soil contains a lot of worms, then she is fertile.
full understanding of the role Haplotaxida come to mankind only recently.But now, many farmers prefer to use chemical fertilizer, despite the fact that they kill every living thing.Today, alternative chemicals found - vermicompost and vermicompost.In fact, it is a magic wand to the ground, because they contain large amounts of phosphorus, potassium, nitrogen, that is exactly the substances that are vital for plants to their full height.
Conclusion
Earthworms are an essential element in soil.Let's look at the process.Autumn leaves fall from the trees and veiled the entire surface of the earth.Immediately after the soil bacteria take the case and leaves decomposed compost to the stage.Then pick up the baton of worms that process leaves the stage of vermicompost.Thus get valuable soil fertilizers.
